1996 Yukon: Very low, low RPM torque, service engine light

[ExEvolution]

I've been having some issues with my 1996 yukon. It started with a high idle and the truck accelerating on its own (it could maintain 30mph without touching the gas pedal). I haven't had a high idle issue for a few months now, but it evolved into a rough, low idle that occurs after medium to heavy acceleration.

I can have this issue sometimes just accelerating up to highway speeds. The service engine light comes on and the rough idle begins whenever I stop the vehicle, when I'm at speeds above 20mph, the car runs smooth. The car will jerk forward a couple times when accelerating from a stop, but if I stop the engine for ~10 minutes, everything will return to normal, except the service engine light, which will stay on for 3 engine starts, not counting the start that caused it to turn on

Things I have had repaired, or repaired myself include:
New fuel pump (approx 2 years ago)
Transmission rebuilt (approx 3 years ago, added a kit to make it last longer)
New spark plugs and wires (4 months ago)
Block Seal was in the coolant system for approximately 2 years, my uncle advised me to do this
Coolant flush (2 months ago)
New alternator (5 months ago)
New thermostat (2 weeks ago)


Any advice on what to do, I can't have this engine die on me before I get my new car

 

[BattelWagun]

I would get the codes scanned and see what its saying. They can be the key to your issues.

 

[Freedom Motorsports]

Try cleaning the throttle body and MAF Sensor and see if that smooths things out.

 

[ExEvolution]

Cleaned the throttle body and mass air flow sensor, but as bad as they were, they weren't my problem.

Turns out the injector spider assembly is most likely the problem causing the service engine light to come on because I had the status codes checked and it showed no status codes at all. He said its common for the injector assembly to bleed or leak on these yukons.

I also have another problem, my transmission is failing again, 2nd gear. He was checking the transmission, no status codes, but a 0.5 second shift into 2nd gear while not even moving, and over 3 seconds while driving. The low power/torque is caused by the failing transmission

I can't put that kind of money into this car again, I was planning on buying an 05 sentra in 3 months, I can't drop 1700 on the transmission again, its only been 3 years since it was rebuilt, and its out of warranty.

 

[blackcoffee]

Get on craigslist and find a used 4L60e best bet right now dude.

 

[BattelWagun]

Get on craigslist and find a used 4L60e best bet right now dude.

+1

you're taking your chances there too, though.

 

[zzptahoe]

hey evo, I am having the same problem with my tahoe. It accelerates by itself, you said the injector is leaking or bleeding? What is that? Hard expensive fix?