If the poppet nozzles are sticking, I would think you would see more symptoms at higher fuel demands. You could check them by energizing the injector with the fuel system charged and the poppet nozzles directed into a jar.

 

Have you tried starting it up while the egr is off? make sure no one is standing right there in front of the engine compartment
let it rev for a sec and blow all that carbon out!

they also make a clean screen sold by a couple people i got mine from tomco its just a gasket with a fine mesh screen that trapes the carbon

and also you can dump high octane in there and drive it hard get that engine running hotter

im tryingmy tps and checking the ground on it too. im basically running down the checklist in my haynes troubleshooting for engine loping then im running down the stalling checklist then ifall that fail i live litterally 20 feet from a chevy dealership and they want
84$ to tell me what the problem is! IM betting thesonnja behive who poked all my wires caused one of them to rust or short to another one that has been poked!


but be sure your looking for the right issue mine lopes really bad revs up then almost stalls mine is constant if your does that run through all the electrical then vacum leaks then cheack the IAC and TPS. bad valve springs could cause this too.

get arepair manual it helps me alot the guys on herehelp alot but its nice to have a how to on everything!!!

 

No, I haven't started it up without the EGR on. I've got an EGR gasket with screen on order (no one around me has it in stock).

High octane went in last week and I've been running it through, though we are wondering if we got some bad gas - had to get it on the road at an unfamiliar station. I had already fixed 3 vacuum leaks under the hood, but it sounds as if I have a couple more behind the HVAC controls.

My MAP is new, the IAC and TPS I swapped over from another engine, just to test. I put in a new O2 sensor but nothing improved, so I put the old one back in.

Mine lopes really bad, too. When I rev it now, it smoothes out. Before, it just loped faster. I put fuel injector cleaner (Chevron with Techron) in it last night and ran 1/8 tank through and it's better. Still rough, but the loping is less. Will run more through, though I'll be gone all weekend.

I did buy Seafoam and will run it through the vacuum lines next week sometime.

As soon as the screened gasket gets here, I will swap that out - and check the EGR for more carbon around the pintle.

Oh, I have the factory service manual - got it on eBay for something like $20. I've run through several checklists already...

 

Have you figured yours out yet? Or at least gotten any more hints from it?

I haven't had a chance to do anything to mine yet, but probably will tomorrow after work. At least to drive it out on the road for a while, running more of the cleaner through under pressure.

The screened EGR gasket won't be here until Friday, so I can't mess with that yet.

 

Well I did have full intentions to work on the engine but i kinda got side tracked!

which i do alot especially if im annoyed with something like i am this engine.
i had some body rust on the truck mainly around the winsheild and it was ugly
so i pulled my seal out of the track around the winsheild and cleaned the rust out and
re sealed it that was fun but also cheap! took about2 hoursI'm sloppy with the poly (sealant)

then i decided to make her look better andgive her a paint job turned her od green that took3 days of wet sanding and filling
that was actually fun!

idid try to wilggle most of the wires around while running but had no luck gonna dig in and get her done after work today!
let ya know what i find!

 

Mine turned out to be the EGR valve, in short.

The FPR leaking caused the top engine to carbon up pretty bad. I seafoamed it in desperation and that sent a great deal of carbon out the tailpipe, but loosened some serious boulder-sized chunks and sent them into the EGR, holding the pintle almost all the way back. I had run fuel injector cleaner through the engine while doing all this, too.

I had some unrelated issues that added to my mess, too: the cap & rotor self-destructed (with less than 50 miles on them, dangit), adding to the rough-running and rich condition, the bf didn't get the coil wire all the way back on when he was testing the wires...stuff like that.

Replaced the cap & rotor, cleaned & gapped the plugs, made sure all wires were fully on and took the EGR off, cleaned it and put it back on with the screened gasket...all has been well since.

 

Just Got done checking the Tps ground first thing i checked I I forget which forum i readt it in but im sure i did and the guy had the same issue I believe he replaced the wire in theconnector instead of the whole thing?

But anyways i tested it and got 0.01 on it while the key was in the on postion.

and after the test it started up godd and ran perfect for about three minutes then back to normal?


Should ireplace the whole harness isnt there a way to just buy a new connector or wire up the old one with new wire?