LQ4 Engine Wire Harness - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sandemonium · 01-05-2007, 04:24 PM

Hello,

While this is my first post I have been lurking on the board for quite awhile.

Many of you have helped more than you know on several occasions with my truck.

I have a '69 Chevy shortbed 2wd that I purchased in Nevada, while I thought I was getting a good deal on the truck I didn't find out what I really bought until I got the truck home to Phoenix and started to disassemble. Needless to say this is turning into a very involved project. The cab had more than it's share of rust, luckily I found a donor cab that is in much better shape.

I am doing a frame off with the help of my 16 year old son and we have made quite a bit of progress.

We have installed 4 wheel disk brakes, a 3/5 lowering kit, Front/Rear Sway Bar, Aluminum Gas Tank, New Upper / Lower cross shafts, Auburn Posi, 4.10 Ring and Pinion, New Axles & most all new sheetmetal.

I am feeling fairly confident that my chassis will work well, but wont know for sure until I actually get it running.

I have ordered an LQ4 with a 4L80E and I am trying to research the available engine wire harnesses available. So far the three I have found are from Speartech, PCMAmerica & Painless.

I have tried searching for the answers, but keep reaching a dead end.

If someone has experience with a wire harness solution I would appreciate hearing from you.

Sorry this post was so long........

Thank you,

Bob

68GenIII · 01-05-2007, 04:34 PM

Bob, I am working on the same swap. I have not decided on a wire harness either. I am pretty sure Im going to use this guy www.Wait4Meperformance.com 574-267-3630. He seem to know his stuff and is very reasonable. Where in Phoenix are you?

Sandemonium · 01-06-2007, 01:12 AM

Quote:

Originally Posted by 68GenIII

Bob, I am working on the same swap. I have not decided on a wire harness either. I am pretty sure Im going to use this guy www.Wait4Meperformance.com 574-267-3630. He seem to know his stuff and is very reasonable. Where in Phoenix are you?

Thank you for the reply.....

I am located in the far north part of Phoenix. Up near Anthem.

Good Luck on your build

shifty · 01-05-2007, 04:55 PM

I can give you a reeaaaaallly good fill-in on this:

http://67-72chevytrucks.com/vboard/s...&postcount=111

http://67-72chevytrucks.com/vboard/s...&postcount=113

Read those two posts or just read THIS PAGE of THIS THREAD.

Wiat4Me is great, but you are required to have a harness first of all, then on top of that, you're only going to get a harness back that will require more wiring on your part to add relays and other crap, which means you need to dig into schematics and other crap. Wait4Me is the absolute cheapest way to go if you don't mind doing your homework.

Speartech is going to give you the least expensive way to get a true plug-n-play harness. It will come with fuses, your fan relays, the fuel pump relay, extra wiring based on where you need the PCM to sit, etc.

Click on the link in my signature to "LS1Tech buildup" for about 13 pages of this install with an LS1 ... they're all GenIII engines and are all roughly the same. Main exception between the LQ4 and the LS1 are:

- Taller intake
- LQ4 always uses a supply and return fuel line directly to the fuel rail (Vette LS1 does, but not F-Body typically)
- The front layout on the LQ4 and LQ9 are different from the LS1; the alternator and A/C compressor are in diff't locations if I remember right, they are mounted high instead of low.

I highly recommend subscribing at LS1tech, and paying special attention to the Conversions and Hybrids forum - they specialize in that engine and you will find so much help there it is silly. A lot of guys here are doing the swap, but even all of them combined cannot amount to the knowledge base at LS1tech

68 short step · 01-05-2007, 07:08 PM

Quote:

Originally Posted by shifty

I can give you a reeaaaaallly good fill-in on this:

http://67-72chevytrucks.com/vboard/s...&postcount=111

http://67-72chevytrucks.com/vboard/s...&postcount=113

Read those two posts or just read THIS PAGE of THIS THREAD.

Wiat4Me is great, but you are required to have a harness first of all, then on top of that, you're only going to get a harness back that will require more wiring on your part to add relays and other crap, which means you need to dig into schematics and other crap. Wait4Me is the absolute cheapest way to go if you don't mind doing your homework.

Speartech is going to give you the least expensive way to get a true plug-n-play harness. It will come with fuses, your fan relays, the fuel pump relay, extra wiring based on where you need the PCM to sit, etc.

Click on the link in my signature to "LS1Tech buildup" for about 13 pages of this install with an LS1 ... they're all GenIII engines and are all roughly the same. Main exception between the LQ4 and the LS1 are:

- Taller intake
- LQ4 always uses a supply and return fuel line directly to the fuel rail (Vette LS1 does, but not F-Body typically)
- The front layout on the LQ4 and LQ9 are different from the LS1; the alternator and A/C compressor are in diff't locations if I remember right, they are mounted high instead of low.

I highly recommend subscribing at LS1tech, and paying special attention to the Conversions and Hybrids forum - they specialize in that engine and you will find so much help there it is silly. A lot of guys here are doing the swap, but even all of them combined cannot amount to the knowledge base at LS1tech

x2 ls1 tech is very helpful

Sandemonium · 01-06-2007, 01:10 AM

Thank you for the feedback. I will continue my research with the LS1Tech forum. At this point I will dig a little deeper with Speartech and PCMAmerica.

Thank you again,

Bob

stsalvage · 01-06-2007, 06:15 AM

I LIKE TO SAY THIS BUT I KNOW I WILL GET BEAT DOWN ON THIS ONE BUT i HATE COMPUTORS IN OLD TRUCKS OR OLD HOT RODS THEY DONT LAST THE SILANOIDS FADE OR GO BAD AND TRYING TO FIND WHICH ONE WENT BAD IS ANOTHER STORY AND ONE YOU NEED TO CHASE DOWN ITS LIKE WHEN THE 1987 THROTAL BODYS CAME ON THE MARKET I'VE HEARD SO MANY HOROR STORYS ABOUT THE GOAST CODES ABOUT THE CODE 42 OR CODE 44 MEANING ECM I HAVE 3 GUYS THAT WORKED ON THEM TRUCKS BACK THEN IT WAS JUNK TECKNOIGY THEY USED IT 1 YEAR THEN WENT TO FUEL INJETED ALL I CAN SAY IS GO BUY THE CRATE ENG AND TRANS WITH COMPUTOR HARNESS THAT YOU WANT AND IT WILL COME COMPLETE ALL YOU HAVE TO DO IS FINE OUT WHERE TO REDILL THE MOTOR MOUNTS AND WHERE IN THE CAB WILL YOU CUT IN TO PUT THE 500 WIREING HARNESS IN AND WHERE TO PUT THE COMPUTOR TRUST ME IF YOU JUST PEACE IT TO GATHER YOU WILL GET A LOT OF FLASH CODES AND ONE BAD THING IF YOU DRIVE THE 4L60E OR THE OTHER ONE ANY DISTANCE WITH OUT IT BEING RIGHT PLAN ON HAVING THE TRANSMISSION REBUILT CUS YOU WILL FRY ONE OF THE CLUCH PACKS AND SILANIOLDS PACKS ME I LIKE NONE COMPUTOR STUFF IT LAST LONGER AND IT COST A LOT CHEEPER WHEN IT BRAKES LIKE THE 700R4 FROM 1987 TO 1992 AND I'M NOT ONE FOR FUEL INJETED I LIKE THE GOOD OLD CARB YA THE GAS MILAGE IS NOT THE BEST BUT ITS A OLD TRUCK BUT THAT ME I SAY LEAVE THEM SIMPLE YOU MAKE IT HARDER THEN IT IS THEN ITS NOT AS FUN TO WORK ON THESE TRUCKS WHERE THE MOST SIMPLEST TRUCKS TO WORK ON FROM ANY TRUCKES EVER BUILT BUT I DO UNDERSTAND TO BE DIFFRENT

68GenIII · 01-06-2007, 10:18 AM

Quote:

Originally Posted by stsalvage

I LIKE TO SAY THIS BUT I KNOW I WILL GET BEAT DOWN ON THIS ONE BUT i HATE COMPUTORS IN OLD TRUCKS OR OLD HOT RODS THEY DONT LAST THE SILANOIDS FADE OR GO BAD AND TRYING TO FIND WHICH ONE WENT BAD IS ANOTHER STORY AND ONE YOU NEED TO CHASE DOWN ITS LIKE WHEN THE 1987 THROTAL BODYS CAME ON THE MARKET I'VE HEARD SO MANY HOROR STORYS ABOUT THE GOAST CODES ABOUT THE CODE 42 OR CODE 44 MEANING ECM I HAVE 3 GUYS THAT WORKED ON THEM TRUCKS BACK THEN IT WAS JUNK TECKNOIGY THEY USED IT 1 YEAR THEN WENT TO FUEL INJETED ALL I CAN SAY IS GO BUY THE CRATE ENG AND TRANS WITH COMPUTOR HARNESS THAT YOU WANT AND IT WILL COME COMPLETE ALL YOU HAVE TO DO IS FINE OUT WHERE TO REDILL THE MOTOR MOUNTS AND WHERE IN THE CAB WILL YOU CUT IN TO PUT THE 500 WIREING HARNESS IN AND WHERE TO PUT THE COMPUTOR TRUST ME IF YOU JUST PEACE IT TO GATHER YOU WILL GET A LOT OF FLASH CODES AND ONE BAD THING IF YOU DRIVE THE 4L60E OR THE OTHER ONE ANY DISTANCE WITH OUT IT BEING RIGHT PLAN ON HAVING THE TRANSMISSION REBUILT CUS YOU WILL FRY ONE OF THE CLUCH PACKS AND SILANIOLDS PACKS ME I LIKE NONE COMPUTOR STUFF IT LAST LONGER AND IT COST A LOT CHEEPER WHEN IT BRAKES LIKE THE 700R4 FROM 1987 TO 1992 AND I'M NOT ONE FOR FUEL INJETED I LIKE THE GOOD OLD CARB YA THE GAS MILAGE IS NOT THE BEST BUT ITS A OLD TRUCK BUT THAT ME I SAY LEAVE THEM SIMPLE YOU MAKE IT HARDER THEN IT IS THEN ITS NOT AS FUN TO WORK ON THESE TRUCKS WHERE THE MOST SIMPLEST TRUCKS TO WORK ON FROM ANY TRUCKES EVER BUILT BUT I DO UNDERSTAND TO BE DIFFRENT

Ever seen the movie "The Anchor Man"? That one part when there in the bosses offices and the character Brick Tanalin (sp?) says " I DONT KNOW WHAT WERE YELLING ABOUT!"

That just kind of how I felt when I read that last post.

I totally disagree with this last post. Computers are way more reliable and run 10x's better then any carb! PCM's (computers) have come along way since the ones you are describing. The 80's computers well thats a different story.

shifty · 01-06-2007, 03:40 PM

Quote:

Originally Posted by stsalvage

I LIKE TO SAY THIS BUT I KNOW I WILL GET BEAT DOWN ON THIS ONE BUT i HATE COMPUTORS IN OLD TRUCKS OR OLD HOT RODS THEY DONT LAST THE SILANOIDS FADE OR GO BAD AND TRYING TO FIND WHICH ONE WENT BAD IS ANOTHER STORY AND ONE YOU NEED TO CHASE DOWN ITS LIKE WHEN THE 1987 THROTAL BODYS CAME ON THE MARKET I'VE HEARD SO MANY HOROR STORYS ABOUT THE GOAST CODES ABOUT THE CODE 42 OR CODE 44 MEANING ECM I HAVE 3 GUYS THAT WORKED ON THEM TRUCKS BACK THEN IT WAS JUNK TECKNOIGY THEY USED IT 1 YEAR THEN WENT TO FUEL INJETED

A couple of notes:

You can run these new fuel injected LS and LQ engines with a carb. It's actually really cheap and easy, but you lose the gas mileage.

I've never heard of a "silanoid" (solenoid) going bad in a PCM on a GenII engine. If it ever did, $50-100 gets you a new PCM. Problem solved.

If you had a choice between running a straight six or crate motor getting 5-8mpg, or an engine with the same displacement and more power getting upwards of 20mpg, which would you choose?

Quote:

Originally Posted by stsalvage

ALL I CAN SAY IS GO BUY THE CRATE ENG AND TRANS WITH COMPUTOR HARNESS THAT YOU WANT AND IT WILL COME COMPLETE ALL YOU HAVE TO DO IS FINE OUT WHERE TO REDILL THE MOTOR MOUNTS AND WHERE IN THE CAB WILL YOU CUT IN TO PUT THE 500 WIREING HARNESS IN AND WHERE TO PUT THE COMPUTOR TRUST ME IF YOU JUST PEACE IT TO GATHER YOU WILL GET A LOT OF FLASH CODES AND ONE BAD THING IF YOU DRIVE THE 4L60E OR THE OTHER ONE ANY DISTANCE WITH OUT IT BEING RIGHT PLAN ON HAVING THE TRANSMISSION REBUILT CUS YOU WILL FRY ONE OF THE CLUCH PACKS AND SILANIOLDS PACKS

I have never, ever heard of anyone having these problems you've mentioned, and I hang out at a forum where people stick these engines and trannies into everything from Mini Coopers to Ford Mustangs and they run for years like they were meant to be there!

The 4l60e has problems. It's a 700R4 for all intents and purposes. Not exactly a crowning achievement in GM's history. 4l80e would be a better choice.

============ EDIT:

I'd like to add one thing about Speartech - they also test every harness they make on an engine to ensure no codes are thrown and there are no cut/frayed/fried wires. This is something not many other places offer.

You only need the one harness. It's really easy to install. There aren't fifty million harnesses to wire in, a single half-dollar sized hole in the firewall with a grommet will get the wires into the cab. Easy as pie. On most harnesses, you only have three things to hook up - purple wire (tie your stock lead from engine bay into harness), then battery power (constant) and ACC power.

68 short step · 01-06-2007, 04:32 PM

Quote:

Originally Posted by stsalvage

I LIKE TO SAY THIS BUT I KNOW I WILL GET BEAT DOWN ON THIS ONE BUT i HATE COMPUTORS IN OLD TRUCKS OR OLD HOT RODS THEY DONT LAST THE SILANOIDS FADE OR GO BAD AND TRYING TO FIND WHICH ONE WENT BAD IS ANOTHER STORY AND ONE YOU NEED TO CHASE DOWN ITS LIKE WHEN THE 1987 THROTAL BODYS CAME ON THE MARKET I'VE HEARD SO MANY HOROR STORYS ABOUT THE GOAST CODES ABOUT THE CODE 42 OR CODE 44 MEANING ECM I HAVE 3 GUYS THAT WORKED ON THEM TRUCKS BACK THEN IT WAS JUNK TECKNOIGY THEY USED IT 1 YEAR THEN WENT TO FUEL INJETED ALL I CAN SAY IS GO BUY THE CRATE ENG AND TRANS WITH COMPUTOR HARNESS THAT YOU WANT AND IT WILL COME COMPLETE ALL YOU HAVE TO DO IS FINE OUT WHERE TO REDILL THE MOTOR MOUNTS AND WHERE IN THE CAB WILL YOU CUT IN TO PUT THE 500 WIREING HARNESS IN AND WHERE TO PUT THE COMPUTOR TRUST ME IF YOU JUST PEACE IT TO GATHER YOU WILL GET A LOT OF FLASH CODES AND ONE BAD THING IF YOU DRIVE THE 4L60E OR THE OTHER ONE ANY DISTANCE WITH OUT IT BEING RIGHT PLAN ON HAVING THE TRANSMISSION REBUILT CUS YOU WILL FRY ONE OF THE CLUCH PACKS AND SILANIOLDS PACKS ME I LIKE NONE COMPUTOR STUFF IT LAST LONGER AND IT COST A LOT CHEEPER WHEN IT BRAKES LIKE THE 700R4 FROM 1987 TO 1992 AND I'M NOT ONE FOR FUEL INJETED I LIKE THE GOOD OLD CARB YA THE GAS MILAGE IS NOT THE BEST BUT ITS A OLD TRUCK BUT THAT ME I SAY LEAVE THEM SIMPLE YOU MAKE IT HARDER THEN IT IS THEN ITS NOT AS FUN TO WORK ON THESE TRUCKS WHERE THE MOST SIMPLEST TRUCKS TO WORK ON FROM ANY TRUCKES EVER BUILT BUT I DO UNDERSTAND TO BE DIFFRENT

they used TBI from 1987 to 1996 (almost 10 yrs) not 1 year, in c1500 trucks..
and codes
42=HO2S bank 1 sen 3 heater circuit
44=HO2S bank 1 sen 3 heater circuit high
so mabey yer fryends is wrongs....
very reliable..... and if you buy one i'll help ya for free install it and get it working..

billyjo · 01-06-2007, 11:20 AM

I had Speartech do my harness and don't have any complaints. Service and knowledge were A+.

Bill

stsalvage · 01-12-2007, 01:51 AM

i have a 1987 chevy truck with the tbi and most wiring shops tell me there a nightmear to work on when it comes to wire harness this truck likes to palsate it runs fine in choke mode but you even get next to the gas pedal it all chanes it gose up and down i've changed every madgal under that hood chanded the tbi injectors and you people tell me there so easy to work on took it to 1 gm dealer hip cost me 400.00 never found problem but told me the intake was sucking air so they had to put a new intak gasket in and did a carb cleaning 3 days later problem came back i think they cleared the codes and the problem went away and sence you can't just hook up a computor to this harness cus there is no reader out there you have to whach the blinky lights for the codes so you got any more bight ideas this is why most GM dealer ship people don't work on 10 15 year old cars or trucks with computors cus every body and there mothers been under the hood this wire harness is still all factory one GM muhcanic told me it may be a fuse able link getting week or going bad i said where do i find it he luaghed and said go get a volt metter and have fun every GM guy has told me the fist TBI unit come out in the camaros they where junk the tbi for the 1987 truck was all buy it self meaning the computor is diffrent then the one in the 1988 they did sevral updates to fix the bugs in the ecu so if you lived in calif i pay you or bet you 500 that you could not figure it out for 500.00 or find all the problems it has now one of the guys did say sence you have a 350 instead of the 305 that might be a problem in my 1987 short bed fleet side with the 5.7 700R4 factory truck came with 5.0 or what ever the litter it is for a 305 but had a lot of people luagh at me for that one hate computors you can keep your milage cus the parts and working on this new stuff cost what a new eng cost for a none computor 5.7 350 brand new changing the spark plugs under teh hood of a 2000 chevy frord or dodge is 400.00 so much stuff you have to remove and i hearwhen the injectors go bad or the coil packs there 130.00 each and there 8 of them man for the long road a head of me i rather not be tracked by the goverment in the tracking device or the new fileing device on every new car bult it keeps a log on how fast you drive where you drive and what you do in your car NO thanks i will stay with my 15 a mile a gallon any day

Deuce · 01-12-2007, 02:41 AM

Have any pics of the truck??

BUDDY · 01-12-2007, 03:14 PM

Quote:

Originally Posted by stsalvage

i have a 1987 chevy truck with the tbi and most wiring shops tell me there a nightmear to work on when it comes to wire harness this truck likes to palsate it runs fine in choke mode but you even get next to the gas pedal it all chanes it gose up and down i've changed every madgal under that hood chanded the tbi injectors and you people tell me there so easy to work on took it to 1 gm dealer hip cost me 400.00 never found problem but told me the intake was sucking air so they had to put a new intak gasket in and did a carb cleaning 3 days later problem came back i think they cleared the codes and the problem went away and sence you can't just hook up a computor to this harness cus there is no reader out there you have to whach the blinky lights for the codes so you got any more bight ideas this is why most GM dealer ship people don't work on 10 15 year old cars or trucks with computors cus every body and there mothers been under the hood this wire harness is still all factory one GM muhcanic told me it may be a fuse able link getting week or going bad i said where do i find it he luaghed and said go get a volt metter and have fun every GM guy has told me the fist TBI unit come out in the camaros they where junk the tbi for the 1987 truck was all buy it self meaning the computor is diffrent then the one in the 1988 they did sevral updates to fix the bugs in the ecu so if you lived in calif i pay you or bet you 500 that you could not figure it out for 500.00 or find all the problems it has now one of the guys did say sence you have a 350 instead of the 305 that might be a problem in my 1987 short bed fleet side with the 5.7 700R4 factory truck came with 5.0 or what ever the litter it is for a 305 but had a lot of people luagh at me for that one hate computors you can keep your milage cus the parts and working on this new stuff cost what a new eng cost for a none computor 5.7 350 brand new changing the spark plugs under teh hood of a 2000 chevy frord or dodge is 400.00 so much stuff you have to remove and i hearwhen the injectors go bad or the coil packs there 130.00 each and there 8 of them man for the long road a head of me i rather not be tracked by the goverment in the tracking device or the new fileing device on every new car bult it keeps a log on how fast you drive where you drive and what you do in your car NO thanks i will stay with my 15 a mile a gallon any day

Man, that is a lot more typing than it's worth. Suggestion, type it in Microsoft WORD first & spellcheck, fix the problems, then copy & paste to here.

I can't talk that long without losing my breath.

Later,
Buddy

68 short step · 01-12-2007, 02:43 PM

alot of people seem to laugh at you, and judgeing from how you spell, your grammer in typing , i can only imagine what you talk like......i would love to help you out ( and i would/could fix it for ya, but i live in texas) spark plugs in 00 trucks could'nt be easier (actually look at one).... and i dont know about all this government tracking deal (who cares about a salvage yard guy anyway, when we cant even track down oshma bin-ladin?)

shifty · 01-12-2007, 05:29 PM

I had to stop about 1/3 way through. Not trying to be insulting, I'm just trying to communicate here. If nobody ever says anything, then you could walk around not knowing forever.

pcmcobra · 01-12-2007, 05:29 PM

www.ls1truck.com
www.nelsonperformance.com

onetonk5 · 01-12-2007, 07:17 PM

does anyone other than s&p make a/c brackets to put the comp up top?what kind of power/mileage can you get out of a truck 5.3 with what computer work?

shifty · 01-12-2007, 07:49 PM

I'll try to answer both. These are really questions for the LS1tech forum, though.

I am 90% sure that you can swap the stock brackets from a 4.8->5.3->5.7->6.0. If you are not happy with the location of peripherals, you should be able to take stock brackets from a vehicle you want and go from there, *i think*. Don't quote me on that. Most guys just get 1/4" plate steel and make their own by welding nuts on the plates and mounting stuff approximately where they should be to hold stuff in place.

I know with the LS1 in particular, maybe not with the other GenIII engines like the LQ4 and LQ9, the A/C compressor is mounted on its own belt in order to isolate it from everything else (this is for performance/power reasons, from what I read in a book).

With regard to mileage, around town 18-21 is what I hear most people getting with a reprogrammed GenIII engine. On the highway, with 3.73 gears, I have heard of people getting 23-27mpg depending on the model of truck, the engine and the tuning. Most people lose mpg because they want that added power kick

onetonk5 · 01-12-2007, 08:01 PM

one of the hot rod shows on spike used a gen3 motor with some kind of prototype bracket system and even had the top rad hose on the motor in a gen2 location.......can remember who made the setup....anyone?
you see any problem with a 5.3 700r4 205 combo? stand alone harness on motor and tci or other kit on the 700?i want to be able to drive my blazer like i want to and have to power i want and not watch the needle fall like it does now. i would imagine with a lifted 4x that oil pan choice isnt that important....or is there a preference?

onetonk5 · 01-12-2007, 08:20 PM

whats the difference other than .7 liter between the 5.3/6.0?

68 short step · 01-12-2007, 08:31 PM

Quote:

Originally Posted by onetonk5

whats the difference other than .7 liter between the 5.3/6.0?

heads, bigger bore, and stroke sorry i cant be more specific...

68GenIII · 01-22-2007, 02:29 AM

Quote:

Originally Posted by 68 short step

heads, bigger bore, and stroke sorry i cant be more specific...

The stroke is the same, actually all the gen iii motors (5.3, LS1, LS6, LS2, 6.0) share the same stroke except the 4.8. and the LS7.

shifty · 01-12-2007, 10:35 PM

Quote:

Originally Posted by onetonk5

you see any problem with a 5.3 700r4 205 combo?

similar install was done in a truck using a carb in one of the two major classic truck magazines over the past year.

longhorn71 · 01-13-2007, 02:26 AM

now i have not done alot of swaps with fuel injection but the tbi set up is real easy to work with or swap to a differenet truck.the tbi does have it problems with injector but the 87 k5 blazer we have has 400,000 kms on the orginal drivetrain with no problems.Last summer i did a body swap on it.the body i found that has in better shape was an 85 one.We swaped the body and added put the fuel injection back in it with out any probelms.it took about 3 nights after work to swap the bodies around and get it running agian

the 6.0 liter from the truck there was 2 different ones.....one with aluminum heads or the cast iron ones.the 6.0 liters in the work trucks(serria 3500 srw long boxs)get about 13-15 miles to the gallon 9were i work there is 9 of them in the fleet 2002-2006s)They all have 4.10s in them and get drove HARD in the oilfeild.one truck has 600,000 kms on it and only the water pump has been changed.It still pulls just as good as the new truck that has 20,000 on it.
Just if you do swap a 6.0 liter make sure you put the 4l80e behind it cause they will destroy the 4l60e s fast.

01-05-2007, 04:24 PM	#1
Sandemonium Proud owner of a 55.1 AD Join Date: Oct 2006 Location: Desert Hills, AZ Posts: 460	LQ4 Engine Wire Harness Hello, While this is my first post I have been lurking on the board for quite awhile. Many of you have helped more than you know on several occasions with my truck. I have a '69 Chevy shortbed 2wd that I purchased in Nevada, while I thought I was getting a good deal on the truck I didn't find out what I really bought until I got the truck home to Phoenix and started to disassemble. Needless to say this is turning into a very involved project. The cab had more than it's share of rust, luckily I found a donor cab that is in much better shape. I am doing a frame off with the help of my 16 year old son and we have made quite a bit of progress. We have installed 4 wheel disk brakes, a 3/5 lowering kit, Front/Rear Sway Bar, Aluminum Gas Tank, New Upper / Lower cross shafts, Auburn Posi, 4.10 Ring and Pinion, New Axles & most all new sheetmetal. I am feeling fairly confident that my chassis will work well, but wont know for sure until I actually get it running. I have ordered an LQ4 with a 4L80E and I am trying to research the available engine wire harnesses available. So far the three I have found are from Speartech, PCMAmerica & Painless. I have tried searching for the answers, but keep reaching a dead end. If someone has experience with a wire harness solution I would appreciate hearing from you. Sorry this post was so long........ Thank you, Bob

01-05-2007, 04:34 PM	#2
68GenIII Registered User Join Date: Apr 2006 Location: Fort Walton Beach, FL Posts: 257	Re: LQ4 Engine Wire Harness Bob, I am working on the same swap. I have not decided on a wire harness either. I am pretty sure Im going to use this guy www.Wait4Meperformance.com 574-267-3630. He seem to know his stuff and is very reasonable. Where in Phoenix are you? __________________ 68 lwb to swb Cummins swap in the works. I promise it will be cool someday.

01-05-2007, 04:55 PM	#4
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	Re: LQ4 Engine Wire Harness I can give you a reeaaaaallly good fill-in on this: http://67-72chevytrucks.com/vboard/s...&postcount=111 http://67-72chevytrucks.com/vboard/s...&postcount=113 Read those two posts or just read THIS PAGE of THIS THREAD. Wiat4Me is great, but you are required to have a harness first of all, then on top of that, you're only going to get a harness back that will require more wiring on your part to add relays and other crap, which means you need to dig into schematics and other crap. Wait4Me is the absolute cheapest way to go if you don't mind doing your homework. Speartech is going to give you the least expensive way to get a true plug-n-play harness. It will come with fuses, your fan relays, the fuel pump relay, extra wiring based on where you need the PCM to sit, etc. Click on the link in my signature to "LS1Tech buildup" for about 13 pages of this install with an LS1 ... they're all GenIII engines and are all roughly the same. Main exception between the LQ4 and the LS1 are: - Taller intake - LQ4 always uses a supply and return fuel line directly to the fuel rail (Vette LS1 does, but not F-Body typically) - The front layout on the LQ4 and LQ9 are different from the LS1; the alternator and A/C compressor are in diff't locations if I remember right, they are mounted high instead of low. I highly recommend subscribing at LS1tech, and paying special attention to the Conversions and Hybrids forum - they specialize in that engine and you will find so much help there it is silly. A lot of guys here are doing the swap, but even all of them combined cannot amount to the knowledge base at LS1tech __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM. Last edited by shifty; 01-05-2007 at 04:58 PM.

01-06-2007, 01:10 AM	#6
Sandemonium Proud owner of a 55.1 AD Join Date: Oct 2006 Location: Desert Hills, AZ Posts: 460	Re: LQ4 Engine Wire Harness Thank you for the feedback. I will continue my research with the LS1Tech forum. At this point I will dig a little deeper with Speartech and PCMAmerica. Thank you again, Bob

01-06-2007, 06:15 AM	#7
stsalvage Scrapper 1 Join Date: Jan 2007 Location: Riverside Calif Posts: 1,649	Re: LQ4 Engine Wire Harness I LIKE TO SAY THIS BUT I KNOW I WILL GET BEAT DOWN ON THIS ONE BUT i HATE COMPUTORS IN OLD TRUCKS OR OLD HOT RODS THEY DONT LAST THE SILANOIDS FADE OR GO BAD AND TRYING TO FIND WHICH ONE WENT BAD IS ANOTHER STORY AND ONE YOU NEED TO CHASE DOWN ITS LIKE WHEN THE 1987 THROTAL BODYS CAME ON THE MARKET I'VE HEARD SO MANY HOROR STORYS ABOUT THE GOAST CODES ABOUT THE CODE 42 OR CODE 44 MEANING ECM I HAVE 3 GUYS THAT WORKED ON THEM TRUCKS BACK THEN IT WAS JUNK TECKNOIGY THEY USED IT 1 YEAR THEN WENT TO FUEL INJETED ALL I CAN SAY IS GO BUY THE CRATE ENG AND TRANS WITH COMPUTOR HARNESS THAT YOU WANT AND IT WILL COME COMPLETE ALL YOU HAVE TO DO IS FINE OUT WHERE TO REDILL THE MOTOR MOUNTS AND WHERE IN THE CAB WILL YOU CUT IN TO PUT THE 500 WIREING HARNESS IN AND WHERE TO PUT THE COMPUTOR TRUST ME IF YOU JUST PEACE IT TO GATHER YOU WILL GET A LOT OF FLASH CODES AND ONE BAD THING IF YOU DRIVE THE 4L60E OR THE OTHER ONE ANY DISTANCE WITH OUT IT BEING RIGHT PLAN ON HAVING THE TRANSMISSION REBUILT CUS YOU WILL FRY ONE OF THE CLUCH PACKS AND SILANIOLDS PACKS ME I LIKE NONE COMPUTOR STUFF IT LAST LONGER AND IT COST A LOT CHEEPER WHEN IT BRAKES LIKE THE 700R4 FROM 1987 TO 1992 AND I'M NOT ONE FOR FUEL INJETED I LIKE THE GOOD OLD CARB YA THE GAS MILAGE IS NOT THE BEST BUT ITS A OLD TRUCK BUT THAT ME I SAY LEAVE THEM SIMPLE YOU MAKE IT HARDER THEN IT IS THEN ITS NOT AS FUN TO WORK ON THESE TRUCKS WHERE THE MOST SIMPLEST TRUCKS TO WORK ON FROM ANY TRUCKES EVER BUILT BUT I DO UNDERSTAND TO BE DIFFRENT Last edited by stsalvage; 01-06-2007 at 06:24 AM. Reason: SPELLING AND DID NOT EXPLAINE IN GOOD DETAL WHAT WHAT I WANTED TO SAY SORRY

01-06-2007, 11:20 AM	#11
billyjo Junior Member Join Date: Oct 2005 Location: Vancouver, WA Posts: 95	Re: LQ4 Engine Wire Harness I had Speartech do my harness and don't have any complaints. Service and knowledge were A+. Bill __________________ 1972 K/5 4x4, Radixed LS1 6.0, 428HP/445TQ, Lingenfelter GT2-3 cam, WCCH 90mm J-Tube, LS2 90mm TB, Stainless Works Headers, NV4500, 4.56 gears, Detroit Lockers, 14 bolt FF, Dana 60, 4 wheel disk Hydro Brakes, dual electric fans, Autometer guages, 4" lift, Zero Rates, Weld Evo Velocity XT8 wheels, 35x12.5x17 Super Swamper SSR's..... http://s72.photobucket.com/albums/i1...tos/?start=all

01-12-2007, 01:51 AM	#12
stsalvage Scrapper 1 Join Date: Jan 2007 Location: Riverside Calif Posts: 1,649	Re: LQ4 Engine Wire Harness i have a 1987 chevy truck with the tbi and most wiring shops tell me there a nightmear to work on when it comes to wire harness this truck likes to palsate it runs fine in choke mode but you even get next to the gas pedal it all chanes it gose up and down i've changed every madgal under that hood chanded the tbi injectors and you people tell me there so easy to work on took it to 1 gm dealer hip cost me 400.00 never found problem but told me the intake was sucking air so they had to put a new intak gasket in and did a carb cleaning 3 days later problem came back i think they cleared the codes and the problem went away and sence you can't just hook up a computor to this harness cus there is no reader out there you have to whach the blinky lights for the codes so you got any more bight ideas this is why most GM dealer ship people don't work on 10 15 year old cars or trucks with computors cus every body and there mothers been under the hood this wire harness is still all factory one GM muhcanic told me it may be a fuse able link getting week or going bad i said where do i find it he luaghed and said go get a volt metter and have fun every GM guy has told me the fist TBI unit come out in the camaros they where junk the tbi for the 1987 truck was all buy it self meaning the computor is diffrent then the one in the 1988 they did sevral updates to fix the bugs in the ecu so if you lived in calif i pay you or bet you 500 that you could not figure it out for 500.00 or find all the problems it has now one of the guys did say sence you have a 350 instead of the 305 that might be a problem in my 1987 short bed fleet side with the 5.7 700R4 factory truck came with 5.0 or what ever the litter it is for a 305 but had a lot of people luagh at me for that one hate computors you can keep your milage cus the parts and working on this new stuff cost what a new eng cost for a none computor 5.7 350 brand new changing the spark plugs under teh hood of a 2000 chevy frord or dodge is 400.00 so much stuff you have to remove and i hearwhen the injectors go bad or the coil packs there 130.00 each and there 8 of them man for the long road a head of me i rather not be tracked by the goverment in the tracking device or the new fileing device on every new car bult it keeps a log on how fast you drive where you drive and what you do in your car NO thanks i will stay with my 15 a mile a gallon any day

01-12-2007, 02:41 AM	#13
Deuce Registered User Join Date: Apr 2004 Location: Calgary, Alberta,Canada Posts: 1,595	Re: LQ4 Engine Wire Harness Have any pics of the truck?? __________________ I know what your thinking.......I have ESPN. Sometimes it's easier to do things the hard way. Fesler Built 1968 Chevy C10....Must resist the urge to mess with it!!

01-12-2007, 02:43 PM	#15
68 short step Senior Member Join Date: Aug 2005 Location: tulsa OK Posts: 3,070	Re: LQ4 Engine Wire Harness alot of people seem to laugh at you, and judgeing from how you spell, your grammer in typing , i can only imagine what you talk like......i would love to help you out ( and i would/could fix it for ya, but i live in texas) spark plugs in 00 trucks could'nt be easier (actually look at one).... and i dont know about all this government tracking deal (who cares about a salvage yard guy anyway, when we cant even track down oshma bin-ladin?)

01-12-2007, 05:29 PM	#16
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	Re: LQ4 Engine Wire Harness I had to stop about 1/3 way through. Not trying to be insulting, I'm just trying to communicate here. If nobody ever says anything, then you could walk around not knowing forever. __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

01-12-2007, 05:29 PM	#17
pcmcobra Registered User Join Date: Aug 2006 Location: Florida Posts: 1,684	Re: LQ4 Engine Wire Harness www.ls1truck.com www.nelsonperformance.com

01-12-2007, 07:17 PM	#18
onetonk5 Cereal Killer Join Date: Jan 2006 Location: Montgomery, Alabama Posts: 639	Re: LQ4 Engine Wire Harness does anyone other than s&p make a/c brackets to put the comp up top?what kind of power/mileage can you get out of a truck 5.3 with what computer work?

01-12-2007, 07:49 PM	#19
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	Re: LQ4 Engine Wire Harness I'll try to answer both. These are really questions for the LS1tech forum, though. I am 90% sure that you can swap the stock brackets from a 4.8->5.3->5.7->6.0. If you are not happy with the location of peripherals, you should be able to take stock brackets from a vehicle you want and go from there, i think. Don't quote me on that. Most guys just get 1/4" plate steel and make their own by welding nuts on the plates and mounting stuff approximately where they should be to hold stuff in place. I know with the LS1 in particular, maybe not with the other GenIII engines like the LQ4 and LQ9, the A/C compressor is mounted on its own belt in order to isolate it from everything else (this is for performance/power reasons, from what I read in a book). With regard to mileage, around town 18-21 is what I hear most people getting with a reprogrammed GenIII engine. On the highway, with 3.73 gears, I have heard of people getting 23-27mpg depending on the model of truck, the engine and the tuning. Most people lose mpg because they want that added power kick __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

01-12-2007, 08:01 PM	#20
onetonk5 Cereal Killer Join Date: Jan 2006 Location: Montgomery, Alabama Posts: 639	Re: LQ4 Engine Wire Harness one of the hot rod shows on spike used a gen3 motor with some kind of prototype bracket system and even had the top rad hose on the motor in a gen2 location.......can remember who made the setup....anyone? you see any problem with a 5.3 700r4 205 combo? stand alone harness on motor and tci or other kit on the 700?i want to be able to drive my blazer like i want to and have to power i want and not watch the needle fall like it does now. i would imagine with a lifted 4x that oil pan choice isnt that important....or is there a preference?

01-12-2007, 08:20 PM	#21
onetonk5 Cereal Killer Join Date: Jan 2006 Location: Montgomery, Alabama Posts: 639	Re: LQ4 Engine Wire Harness whats the difference other than .7 liter between the 5.3/6.0?



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01-13-2007, 02:26 AM	#25
longhorn71 Senior Member Join Date: Sep 2004 Location: CANADA Posts: 1,681	Re: LQ4 Engine Wire Harness now i have not done alot of swaps with fuel injection but the tbi set up is real easy to work with or swap to a differenet truck.the tbi does have it problems with injector but the 87 k5 blazer we have has 400,000 kms on the orginal drivetrain with no problems.Last summer i did a body swap on it.the body i found that has in better shape was an 85 one.We swaped the body and added put the fuel injection back in it with out any probelms.it took about 3 nights after work to swap the bodies around and get it running agian the 6.0 liter from the truck there was 2 different ones.....one with aluminum heads or the cast iron ones.the 6.0 liters in the work trucks(serria 3500 srw long boxs)get about 13-15 miles to the gallon 9were i work there is 9 of them in the fleet 2002-2006s)They all have 4.10s in them and get drove HARD in the oilfeild.one truck has 600,000 kms on it and only the water pump has been changed.It still pulls just as good as the new truck that has 20,000 on it. Just if you do swap a 6.0 liter make sure you put the 4l80e behind it cause they will destroy the 4l60e s fast.

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