5.3 first start wont start

[mrhino]

I need a little help guys, went to start my 5.3 project for the first time today and it wont start. here's the deal. It has 58psi on the fuel rail, it has spark, it sounds just like the timing is off. shot to shots of starting fluid in the throttlbody and it fires right up and and will run for a second or so till the either is gone. So it sounds like the injectors aren't working, but i checked and they all have power. What else would be keeping it from running on its own. thanks for the help

[68GMCCustom]

I have heard of people having to do a crank related "relearn" to the PCM. Kind of like a crank position sensor/PCM calibration.

[foamypirate]

Originally Posted by 68GMCCustom

I have heard of people having to do a crank related "relearn" to the PCM. Kind of like a crank position sensor/PCM calibration.

As far as I am aware, this shouldn't prevent the engine from starting. It should just give a CEL.

[glock35ipsc]

Something to check..... this happened to me when I went to fire mine for the first time, only on the ignition coil side. But the same theory applies; be sure that the trigger wire for your fuel pump relay has 12VDC in BOTH the run AND crank position. On mine, I had 12VDC to the ignition relay when the key was in the run position, but power disappeared when the key was in the crank position. Found a wire that had power during both positions, and it fired right up.

Also, you have power to the injectors, but have you checked to be sure they are actually pulsing fuel? I have heard of many, many cases of someone trying to start a bone yard Gen III/LS engine for the first time after it has been sitting for several months, only to find out most if not all of the injectors were plugged.

[mrhino]

Originally Posted by glock35ipsc

Something to check..... this happened to me when I went to fire mine for the first time, only on the ignition coil side. But the same theory applies; be sure that the trigger wire for your fuel pump relay has 12VDC in BOTH the run AND crank position. On mine, I had 12VDC to the ignition relay when the key was in the run position, but power disappeared when the key was in the crank position. Found a wire that had power during both positions, and it fired right up.

Also, you have power to the injectors, but have you checked to be sure they are actually pulsing fuel? I have heard of many, many cases of someone trying to start a bone yard Gen III/LS engine for the first time after it has been sitting for several months, only to find out most if not all of the injectors were plugged.

Ill check that i have 12v to the injectors and fuel pump on crank. how would i check to see if they are actually pulsing fuel. I was also thinking if I had each injectors plug in to the correct pigtail,

[mrhino]

I checked and I Do have power in the start and run position, after cranking it for the check I felt each header tube and only one (cylinder 4)was hot. so I think you are ont to something about the injectors being clogged. I pulled the rail loose and sure enough only cylinder 4's injectors was wet. Although not a junk yard engine, it has been sitting around a few years. what do suggest as my best coarse of action to cleaning them.

[Thealien]

Some have had success soaking the pintle end (don't get the electrical connector part wet) in seafoam.

There are a few cleaning/balancing companies out there that will clean a set for between $1-200?

I got lucky and found an exact set taken out of an engine with only 100 miles on them and had the guy next day air them to me. The total cost with shipping was about $150-175 or about the cost of 2 new injectors. Mine has been running great for 2000+ miles now!!

Good luck

[mcbassin]

If you soak them in seafoam or equivelent don't go too deep. I would just soak the tip. You might want to take the orings off too.
good luck!

[Big Port Jimmy 6]

I have a local parts store that services injectors, call around to the non big box parts store in your area and see, or send your here and we will have them done. Jay

[Juiced06GTO]

I thought I had the same problem when I went to fire mine, turns out stupid me crossed up the feed and return lines! I flipped them around and she fired right up! I have a set of stock ls2 injectors kicking around from my gto, but you would need an elec adapter to make them work. Let me know how you make out...

[mrhino]

Thanks for everybodys help. what iv found out is I have 6 out of the 8 injectors are stuck, or clogged. Im going to attempt to free them up using seafoam. whats the worst I could do to them they already dont work.

[tk-mpl]

What year is your engine... You will have power at the injector and the PCM will toggle the ground. To check it if you don't have a noide light just put a 194 bulb in the connector.. Just bend the terminals of the bulb straight and put them in the injector connector, just don't spread the connector terminals...

[mrhino]

Originally Posted by tk-mpl

What year is your engine... You will have power at the injector and the PCM will toggle the ground. To check it if you don't have a noide light just put a 194 bulb in the connector.. Just bend the terminals of the bulb straight and put them in the injector connector, just don't spread the connector terminals...

The engine is a 01. I used my test light(hooked to ground) and it did pulse, but the injector itself would not open. last night I took them all out of the rail and spent some time with some carb clean and air pressure. I powering each one on and off a few hundred times, and got them all to open and close. I ended up getting some nasty stuff out of them. So I soaked them all night in some solvent. today, I will put them back in the rail pressurerize the rail with more solvent, and hopefully get them to spray nice and clean. with a good pattern.

[68GMCCustom]

eeeewwwwwww nasty!

[Shon]

I had 4 of 8 injectors clogged and replaced, found this out by pulling the Fuel Rail up and having a catch can and watching the injectors fire as we tried to start. The noid lights lit up like they were working b/c they were getting the right signals to fire.

Also if that doesnt work, make sure the VATS is turned off in the PCM.

[mcbassin]

Originally Posted by Shon

I had 4 of 8 injectors clogged and replaced, found this out by pulling the Fuel Rail up and having a catch can and watching the injectors fire as we tried to start. The noid lights lit up like they were working b/c they were getting the right signals to fire.

Also if that doesnt work, make sure the VATS is turned off in the PCM.

Shon,
So once they are clogged, they can't be cleaned? I've got a couple of sets that have been sitting for a few years. More than likely they will be clogged too?

[Shon]

I dont see why they cant be cleaned, I happened to have another set sitting here that I just replaced each clogged one with ones that worked and rolling out.

Main thing is getting the really cleaned, I am not sure if just soaking them will work, but it might.

[68GMCCustom]

If you have several sets, and a way to measure they're output....if you can come up with a "matched set" of injectors... is worth a few hp.

[mrhino]

It's running, whoa hoo!
I wanted to say thanks for all the advise I got. I Just thought I share with everybody what I came up with. maybe it will help somebody else. What I found was 7 of my injectors were stuck from sitting for however long, after checking that the pcm was triyng to pluse them, I removed them from the fuel rail, I put power to each injector, on and off, spraying carb cleaner in the tops until I could here each one open and close. ( there is a small screen or filter inside each injector, so made sure that was as clean as possible. I was getting a bunch of crap out of them. I then submerged them in berryman's b12 carb cleaner overnight.(remove the o-rings first) The next day, I again put power to each one and made sure i was getting cleaner though each injector I then put on new o-rings, put them back into the rail, used my OTC fuel injector cleaner and pressurized the rail to 50lbs with the B12 and gas. Then powered each injector on and off while watching to see that i got a good spray into my little bucket. All the injectors seam to a have a nice fat spray pattern, so I put it back togeather, ran the engine on the rest of my cleaner & gasoline cocktail.
obviously this is not a professional bench cleaning or flow charting, but it has saved me a $h!t load of money, over new injectors, and it showed, despite sitting for a while my engine does run and sound good.

[Shon]

Sweet

[Puglia10]

Now you got me worried! my motors been sitting for about a year i think

[74project]

how did you get ur o rings off without messing them up?

[mrhino]

the original orings were destroyed when i first took them out, a few months back when I cleaned the engine before the install. the second set were destroyed when i soaked them overnight in cleaner, so Im on my third set. but a new set should go in and out of the rail fine (put a little oil or vasoline on them). then you can use a pick set to get them off of the injector.

[mrhino]

Hey Guys After i got the truck running, (Believe it or not) Iv have run out of gas on it. So I started A new build thread to help motivate me. It starts at the beginning, when I got the truck and will go all the way to the end. it will show the Porterbuilt trailing arms I put in, the four wheel disc brakes. the engine install, the $65 jeep fuel tank I used, the factory engine harness that I went through, the fuel fill location, body work, custom paint, ultra leather interior and lots of other stuff.

Check it out! the link is below