My 95 z28, a4, will sputter like crazy under any load at all. 95% of the time, it will idle for hours on end, and be fine. Once in a great while, at idle, it will be at around 1500 rpm, and the tach jumps around between 800-5500rpm. Once I put a load on the car, it acts like it isnt getting fuel, and then stalls. I know its getting gas becuase you can smell the gas when it dies, and you try to crank it over again. It wont start right up, I have to let it sit for a few minutes. Could the fact that my Intake Elbow is ripped at the bottom? It has a new opti, coil, and ICM too...

 

It depends how bad the rip is.... I would fix that and check anyways

With the rip, the mass airflow sensor is not reading an accurate amount of air entering the engine. That sensor is what controls the air/fuel ratio and other things. So the rip could totally be throwing those readings off.

If you fix that and it still doesn't help. Then you need to look into other ignition components (coil, ICM, opti, etc.) There are tests you can do to help narrow down the problem (see shoebox's site). Also wouldn't hurt to throw a fuel pressure guage on there real quick just to verify. Just because you can smell it doesn't mean it is enough always

 

Ok. The coil, opti, ICM are all new (within a week old. The rip is sorta bad, I dont know how to describe it. What would be a way to fix it? I can get a fuel pressure gauge today also, but what would be the correct reading for a LT1?

 

If you put the guage on the shrader valve, then just turn the key on - you should see 41-47 psi. of pressure just with the key on. You can also run the motor and make sure that you don't notice any erratic things going on with the fuel pressure...

Did you intall the opti, etc. yourslef? Are you sure that it was all installed correctly (not plug wires crossed, etc.)

 

To fix the rip, you COULD try some really good glue or tape. But if it were me, then I would just buy a new elbow all together or get a good used one. That way you know that it is definitely not part of your problem

 

Yes, I installed the opti myself. Why the hell I didnt think to check plug wires, I dont know. Once i get home from school today Ill check that.

 

ok - do that and then post up after.

I am leaning more toward that rip in the intake elbow though. If a plug wire were crossed - then it would not be able to idle fine without any problems for most of the time.

 

It ended up being that the opti connector was messed up. Put another one on there, and it runs like a champ!