I'm wondering if this scenario is possible.

My stumbling problem I believe is attributed to an excess of fuel in the system. Oil smells like gas, really rich A/F, LTerms bottoming out at idle.

The car is FINE when cold started, but after 30-45 seconds, the problem starts to appear, which is a fast throttle stumble/hesitation.

Would it be possible for a fuel injector to be sticking open once it starts warming up, and how could I go about checking on this?? I've done the pull the rails and pressurize the system test, with no leaks noted.

 

I think that would be very unlikely. Have you ever had the car dyno-tuned? If your PCM program is stock, I doubt the tuning is on par for a cammed car.

If you have tuned the car, and it has ran fine in the past with the cam, I would check for leaks in the exhaust prior to the O2 sensors. Air leaking into the exhaust stream would signal as your car running lean, which the PCM would counter with more fuel that you don't actually need. Another question would be in regards to the O2 sensors themselves (age, condition).

If you are really set on the injectors being faulty, you could send them out and have them tested on an ASNU injector service machine. There, you can actually see the actual spray patterns of each injector, as well as clean them far beyond what "pour-in" stuff can do. Here's a link that explains it a little better:

http://www.niehoff.com/whatsnew/whatsnew1.html

 

The car is on it's 9th revised tune so far. Tuning is fine. I just thought that the injectors may play a part.

Something is dumping a ton of extra fuel into the mix on me. It's not my TPS as I've put two different ones on the car with the same results.

 

A couple of questions;
are the injectors stock?
Fuel pressure at idle and WOT?
Checked for intake and exhaust leaks?
Lazy O2 sensors? Might be dead from too much fuel.


If you have be doing quite a bit of tuning, I would maybe put the stock file back in and see if the problem goes away. I have gotten way off the mark on a tune before and found it was easier to start from a stock file again.
You can always send your injectors to mine or another shop, but I would rule out other things first. It doesn't sound like an injector problem by what you describe.
Good luck, and keep us informed.

Gordon
WitchHunter Performance
Fuel Injector Cleaning & Flow Testing

 

Have you looked for fuel in the FPR vac line indicating the diaphragm has a hole in it. This leaks(actually sucks) fuel into the intake. Both this problem and a sticky fuel injector will cause the fuel pressure to drop after the car is turned off. Put the fuel pressure gage on it and watch it after the engine is shut off.

BTW, both of these problems cause the car to have to crank more than usual to start. Do you have an unusually long cranking time?

 

No fuel in the Vac line for the pressure regulator.

The car fires up instantly. No hesitation when cranking at all. It's not a leaking injector from what I can tell.

 

If I were you I would replace or clean the EGR and check the fuel pressure after the engine is shut down.