INNOVATE DLG1 Wideband O2 Oxygen Sensor Tuning Diagnostics Logging Air Fuel Ratio etc

[Jay2Cor517]

Hey Gregski, in post #68 you said there was a "gotcha" with the gauge--that it didn't come with a patch cable to work with the rest of the equipment. Is the correct part number for that cable 3846?

[Gregski]

Originally Posted by Jay2Cor517

Hey Gregski, in post #68 you said there was a "gotcha" with the gauge--that it didn't come with a patch cable to work with the rest of the equipment. Is the correct part number for that cable 3846?

that looks right, you need the male male ends like on this cable to go between the female female ends of the gauges, so this is it

[Gregski]

first of all thank you all for reading and providing positive feedback, I am trying really hard to keep this very detailed to see if we can help each other out

so its been a while since I tinkered with the truck, here in California we went from 4 years of drought to one of the most rainiest seasons in 30 years, point being the temperature and humidity extremes were insane for carburetor tuning so I limped through the winter

the last thing I just did was replace the Accelerator Pump Cam, to see if I could fix the lean stumble\hesitation condition under light throttle acceleration, truck accelerates fine when I step on the throttle, but if I am pulling away from the green light with a cop next to me or my grandma in the passenger seat, the truck leans out way too much, like 20 AFR

I'll be honest with you I was a bit intimidated at first, I did not understand what the cam does, I understood what the nozzle aka squirted did, and I upped mine from a .031 to a .035 but again what does the cam do

well recently I re read a chapter in Dave Emmanuel's HOLLEY CARBURETORS Performance, Street, and Off-Road Applications book, and finally the light bulb went on.

"... the accelerator pump cam is a timing device."

so armed with that mantra I remembered these cam graphs, so I pulled one up and stared at it, now I still aint no expert, but I like to know what the extremes are, ie whats the minimum, whats the maximum, type a mentality,

and here we see that the Blue Cam delivers a shot the soonest, and the Pink Cam delivers a shot the latest and everything else falls somewheres in the middle, ok, cool, we can work with that (I think)

[Gregski]

remember the Accelerator Pump is just a helper, there are two circuits in the carb (for purposes of this discussion we won't bring in the secondary circuit), the idle circuit and the main circuit. The Accelerator Pump helps with the transition from the way gasoline oozes in the the carb via the Idle Circuit, to the way it gets sucked in via the main jets/circuit using the vacuum created with higher RPMs (venturi vacuum ie vacuum inside the carbs throat, not intake manifold vacuum, there's a difference) so when the gas pedal is pressed down a ton of air enters the carb, and the gasoline goes ah snap, that's our queue, here we go boys, and the Accelerator Pump gives the gasoline a kick in the pants to get in there as fast as the air did, once the gasoline starts being sucked in with the air, the Accelerator Pump takes a break cause it's work is done, then you are running on the Main Circuit

so the first thing you have to do is find out what color accelerator pump cam you have, and just as importantly what hole is it screwed in at, there are two holes, #1 and #2 on the carb bracket, and the cams themselves can have anywhere from 1 to 3 holes

well I like to remove the cam and look at it, that way I can wipe it clean and see if it is damaged or warn out, so mine turns out to be Orange and it was in the #2 position

Ok, so I think I just got lucky cause I said I am going to try the Blue Cam in the #2 position to get the squirt of gasoline as fast as possible and see what that does, and if that makes it worse, I will go the other way and try the Pink Cam second hole in the #1 hole in the bracket, to get a delayed shot, this is all based on the graph above, I was going to try the two extremes

turns out the Blue Cam works amazeballz so I just left it in, light throttle acceleration be damned, truck runs fantastic!

[LT7A]

Glad to hear that you got Rusty's acceleration back on track. I read these updates avidly and I hope to become as adept with the Q-jet as you are with your Holley. Not trying to start a Q vs. H controversy here. I just plan to work with what I have until it runs out of steam.

I got a chuckle out of your response here:

Originally Posted by Gregski

makes for great conversation and takes the pick up line to a whole new level: "hey baby I can make your engine run at a perfect stoic 14.7 AFR all day long!" jk

I know you're married, but if you weren't... There's gotta be places in Sacramento where you can drop the "you won't believe how high my vacuum is at idle speed" line. Poor unsuspecting gal will think that you're a catch because you do a lot of housework even when you're feeling lazy.

OK, it's a bit of a stretch and it barely moved the needle on my humor-meter, but it makes your wit look just that much sharper.

[rgunlock]

I've just re-read this thread because I'm to the point on my truck build that I'm ready to dial in the tune. Want to commend you again Gregski on the detail you provide here, although I wish the carb detail were Q-Jet

So it's been about a year and a half since you last posted so you've been through all your seasons again. Are you cycling through known carb "recipes" now as climate changes? Do you find that you're still paying any attention to these guages?

I'm also wondering whether some of the other guys that indicated they were ready to pull the trigger on one of these setups were able to duplicate your success?

[Gregski]

Originally Posted by rgunlock

I've just re-read this thread because I'm to the point on my truck build that I'm ready to dial in the tune. Want to commend you again Gregski on the detail you provide here, although I wish the carb detail were Q-Jet

Thank you, I must admit there's been times when I refer back to my own threads, I'm just waiting for the day I start arguing with myself, ha ha. On a serious note there's a guy on YouTube that gives some serious love to the Q-Jets wish I could provide you a linky link, search and ye shall find.

Originally Posted by rgunlock

So it's been about a year and a half since you last posted so you've been through all your seasons again. Are you cycling through known carb "recipes" now as climate changes? Do you find that you're still paying any attention to these gauges?

I read the gauges daily, stare at them at every red light, keeps me from texting on my cell phone, jk. The truck and I have been through a lot since I last posted, ie an entire brand new Edelbrock Top End swap. Check out the sister thread Restoring Rusty for the details. I live in California so I was making adjustments during the fire season cause of the smokey air. It's first week of Fall now and I think Rusty is do for a Fall tweak now.

Originally Posted by rgunlock

I'm also wondering whether some of the other guys that indicated they were ready to pull the trigger on one of these setups were able to duplicate your success?

me too, best of luck to you allz

[Gregski]

alright so here is an update two years and about 17,000 miles later

1. for some strange reason the AFR gauge started cutting out on me a few weeks ago, it sometimes won't turn on at all, I have to hit the dash with my fist Old Skool style for it to come on, yet sometimes it comes on just fine. I mentioned this to Mopar Seth, my buddy running the same setup on his Dodge 100 pickup and he says you know what mine started doing the same thing, I think he only had his for 1 year.

2. one of the two O2 sensors died so the gauge shows the E8 error, I tried to clean it gently but no dice, it's kaput

so I ordered two BOSH LSU 4.9 name brand O2 sensors online, they aren't cheap, I think $50 bucks a pop is the best deal I could find, I bought two so that I replace both of them at the same time so they get even reading, is my logic anyway

and tonight I got tired of the cutting out gauge so I tore the gauge cluster out and checked my wiring and low and behold I was actually surprised how nice and tight all the connections were so I don't think it was my amateur installation

[akart]

Starting w/that 1460 Holley carb about how much money did you spend on all those Holley parts? You know like 1450 kit. springs,pumps,jets and all that stuff. Can't wait to check out my Edelbrock 1405. I did change out some rods and jets as recommended on this forum. Runs great 13 MPG mixed and plenty of snort. Idles well... Wonder if I should just leave well enough alone. A couple hundred bucks could buy (I was gong to say a lot) of gas and there is the bit of welding and the time........ I am getting old!

[Gregski]

Originally Posted by akart

Starting w/that 1460 Holley carb about how much money did you spend on all those Holley parts? You know like 1450 kit. springs,pumps,jets and all that stuff. Can't wait to check out my Edelbrock 1405. I did change out some rods and jets as recommended on this forum. Runs great 13 MPG mixed and plenty of snort. Idles well... Wonder if I should just leave well enough alone. A couple hundred bucks could buy (I was gong to say a lot) of gas and there is the bit of welding and the time........ I am getting old!

That is a great question and the honest answer is I don't know maybe $400 in total in the very end. Keep in mind when I bought that Holley carb I did not know anything about Holley carbs, if I was to do it again I would spend more money and get a QuickFuel carb which is based on the Holley modular design but offers full tunability, they are a company down the street from Holley, ha ha.

It's not about the money/time wasted on tinkering with this, it is not just about fuel economy either ie MPGs it is about running a healthy motor, not over heating it, not fouling the plugs. A happy engine is a happy truck is a happy driver!

I run an Edelbrock 1407 (3028) carb on my '71 GMC (350 V8 automatic) I will be buying AFR gauges for that truck soon, maybe switching brands and going with AEM instead, and can't wait to tinker with metering rods etc. ha ha, I hope to do a write up on that as well, should be fun, it's a different animal with an automatic transmission and all

[rgunlock]

Hi Greg, just got my AFR and vacuum gauges hooked up yesterday. On my drive into work this morning, I was surprised to find that I'm apparently running too lean with my QJet most of the time, particularly at idle. Back on post #99 you describe what your targets were for idle, part throttle, etc. Did you find a good single info source providing target range for each case, or is that something you've come up with yourself from all the books, articles, etc. you've read. Also, I assume that your target AFR ranges aren't specific to your Holley carb, but thought I'd ask. thanks, Rick

[Gregski]

Originally Posted by rgunlock

Hi Greg, just got my AFR and vacuum gauges hooked up yesterday. On my drive into work this morning, I was surprised to find that I'm apparently running too lean with my QJet most of the time, particularly at idle. Back on post #99 you describe what your targets were for idle, part throttle, etc. Did you find a good single info source providing target range for each case, or is that something you've come up with yourself from all the books, articles, etc. you've read. Also, I assume that your target AFR ranges aren't specific to your Holley carb, but thought I'd ask. thanks, Rick

awesome and yes my numbers come from aggregation of sources plus my own experiences, since doing this write up I have given up chasing the perfect 14.7 for idle now 13.5 is fine

so 15ish for cruise

12ish for power

keep in mind this is the worst time of the year to tune, humidity, temp, humidity, and humidity lol

but play around, divide and conquer

[rgunlock]

Thanks for the response, and basically for making me aware of this tool and its usefulness. Humid or not, right now my idle after driving several miles (fully warmed up) is between 15 and 17 so I'm thinking some tweaking of the mixture is in order. I have such a strong fuel smell that I was just sure I was idling rich. But, then again I'm already at 15.1-15.4 at cruise so that seems to be good. Amazing what you can find out after a single drive with one of these gauges.

[Gregski]

Originally Posted by rgunlock

Thanks for the response, and basically for making me aware of this tool and its usefulness. Humid or not, right now my idle after driving several miles (fully warmed up) is between 15 and 17 so I'm thinking some tweaking of the mixture is in order. I have such a strong fuel smell that I was just sure I was idling rich. But, then again I'm already at 15.1-15.4 at cruise so that seems to be good. Amazing what you can find out after a single drive with one of these gauges.

before going twisting away your idle mixture screws please do the following:

1. check your timing, if its low like 10° bump it to 12° then test drive it, you may need to decrease your idle speed a bit to compensate for the higher RPMs, observe the gauge, then bump it to 14°, rinse, lather, repeat

2. check/adjust float levels before twisting the idle mixture screws

not preachin' or soap boxin' just honestly trying to help

[truckin 79]

Anyone else using a air/fuel gauge? I put in a previous thread that I have had trouble passing emissions in CO. I thought I fixed it with EGR replacement but that was wishful thinking. I took to a local garage and asked them to see if they could get it within limits to pass emissions. They charged me 100 bucks and said carb needs rebuilt. I just rebuilt carburetor and the guy says well then you need to buy another carb. I buy another carb rebuilt from Rockauto 260 and take to emissions station, I thought I felt a little improvement while driving truck. Well with new carb it failed even worse then old carb. I thought I would buy a A/F gauge and luckily Gregski has a good write up on install and tuning. I just wanted to know if people who had these gauges averaged the 14.7 or what readings were like. I bought a AER gauge from Ebay 170, I thought it was better then paying some mechanic who did not really care anyway.
Oh yeah thanks alot Gregski for all the great info on this and other thread. I think you should print out all these pages out and sell online as a how to book.

[Gregski]

Originally Posted by truckin 79

...I put in a previous thread that I have had trouble passing emissions in CO.

I am sorry to hear about your SMOG woes, living in California (pronounced Emission Constraint Capitol of the Globe) I feel your pain, though here vehicles like my truck 1975 and older are exempt thank god

couple tips if I may:

0. read the SMOG report, it tells you where you failed and how bad, I had a car that would pass emissions but fail some other thing like visual inspection or something cause a hose was missing, or some nonsense like that, how bad does it say you missed the cut off by?

1. check your timing with a timing light

2. do not SMOG a cold vehicle, take it for a nice 30 mile drive on the freeway on a day where the SMOG shop won't be busy, and then pull up right to their car port ready for a test

3. check your timing, is your coil good or bearly limping along

4. do not fall for any of that Sea Foam crap, if you feel like wasting your money on snake oils, please send the cash to me instead, ha ha

5. read your spark plugs, put in new ones, gap them properly, are you using an HEI distributor if so are the plugs gapped big like .045 or even .050

6. hey, have you checked your timing, ha ha

7. I change my oil and oil filter and air filter before smoking a gross poluter as well, every bit helps, plus it's just good overall maintenance

8. how old is your muffler, maybe a new $100 turbo one will help

Originally Posted by truckin 79

I just wanted to know if people who had these gauges averaged the 14.7 or what readings were like.

That is a great question, and as a newb we all chase that perfect stoic number, but as we get more experienced we realize tuning a bit richer is more realistic, so shoot for like 13.5. However remember there are three conditions and 14.7 is not acceptable for all of them.

1. idling at a red light (ok shoot for 14.7) but more likely be happy with 13.5, always safer for the engine to run richer than leaner, too lean can damage your engine

2. cruising on the freeway, acceptable range is 15.5(ish) as it does not take much horse power to keep the vehicle moving, something like 40 horse will do it

3. power, use the poor man's dyno for this, aka a nice hill on the freeway, with no heavy traffic around floor it up that hill and have a buddy watch that AFR gauge, for a chevy small block 11.5 AFR is a nice horse power pull

of course all these numbers are just a guide, your engine/truck may want to ebb and flow a bit differently

Originally Posted by truckin 79

Oh yeah thanks alot Gregski for all the great info on this and other thread. I think you should print out all these pages out and sell online as a how to book.

thank you so much, I appreciate that, I need to graduate to making videos, but I have the face for radio, ha ha

[truckin 79]

So still interested in anyone with familiarity with A/F on a Q-jet. I drive my 79 to the junkyard on weekends, not a daily driver. So truck usually starts right up after two cranks with choke down on cold morning A/F is about 12. As truck warms up on cold mornings going to junkyard about 35 miles (40 minutes one way)away I get 14-15 at stop lights and 16 A/F while cruising about 55-65 there. When I start the drive back home truck at stop lights hits about 16-17 A/F and while cruising at 55-65 hits about 17-18 sometimes gauge wont read how lean. If I step on gas it hits 13 but once out of gas I start getting 17-18 at cruise and idle. I am about 12 degress BTDC right now and seems to run okay, I am just worried that I am running to lean. The truck does not back fire or stumble while driving. On acceleration it kind of sounds like put-put-put out of the exhaust.

[rgunlock]

I haven't done any changes to my tune since my last posts. Was told by a knowledgeable source that with my GM Performance 350/290 I'd never be able to tune my Quadrajet so I'm happy with it unless I first change out the cam. Too much cam for too low of compression ratio. That said, I get 15-15.5 at cruise (1800-2000 RPM) and after the truck is totally warmed up it bounces around between 16-18 idling at ~800 RPM at lights. Much lower numbers when the choke is still involved. My base timing is at about 16 BTDC.

[Loco83]

[Gregski]

Originally Posted by Loco83

LOL, and get it wrong 90% of the time, ha ha, but hey some people don't like money (think sending all that rich fuel out the tail pipe)

[truckin 79]

I did try tuning by ear and RPM gauge and still failed emissions. I think the O2 gauge is still a good investment especially for trying to tune your carburetor. It can also be a bit distracting just watching the gauge all the time to see what air/fuel is doing. It is good to know someone is getting similar numbers. I thought the altitude in CO was causing the overly lean condition. The funny thing is the other day I found a good plastic air intake hose at the junkyard and put on the truck. It was still kind of dirty but to cold in CO to wash with soap and water. I will once the weather gets nicer but so far air/fuel has gotten better. On the last couple trips to junkyard the truck has not leaned out past 18 while cruising and at idle it is about 15. It honestly seems a little peeper off the line with just the plastic air hose installed . It is still kind of doggy past 40 miles an hour. I need to adjust the kick down switch on the th400 I think. I step on gas all way to the floor and I dont feel it down shift. Oh well one more thing to mess with.

[Gregski]

Originally Posted by truckin 79

I did try tuning by ear and RPM gauge and still failed emissions. I think the O2 gauge is still a good investment especially for trying to tune your carburetor. It can also be a bit distracting just watching the gauge all the time to see what air/fuel is doing. It is good to know someone is getting similar numbers. I thought the altitude in CO was causing the overly lean condition. The funny thing is the other day I found a good plastic air intake hose at the junkyard and put on the truck. It was still kind of dirty but to cold in CO to wash with soap and water. I will once the weather gets nicer but so far air/fuel has gotten better. On the last couple trips to junkyard the truck has not leaned out past 18 while cruising and at idle it is about 15. It honestly seems a little peeper off the line with just the plastic air hose installed . It is still kind of doggy past 40 miles an hour. I need to adjust the kick down switch on the th400 I think. I step on gas all way to the floor and I dont feel it down shift. Oh well one more thing to mess with.

sounds like you are making great incremental progress, and that's what it is all about, hey you want your truck to run like she's never ranned before, ha ha

take her to get that new LS engine for an LS Swap, I swear that SBC will sense it's days are numbered and it will be on it's best behaviour

[MySons68C20]

GREAT thread Gregski!! I just finished reading the whole thing and it is filled with tons of helpful info. This will help immensely getting my QFT 750 carb set up correctly.
Thanks so much for the stellar write up & pics!
I know this is an older thread but it needs to be back to the top.

[Gregski]

Originally Posted by MySons68C20

GREAT thread Gregski!! I just finished reading the whole thing and it is filled with tons of helpful info. This will help immensely getting my QFT 750 carb set up correctly.
Thanks so much for the stellar write up & pics!
I know this is an older thread but it needs to be back to the top.

man you just made my day, thanks for the kind words, sometimes I think only my mom reads these, sometimes I think not even she does, I know I don't, ha ha

[doowopper]

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