I'm having a issue... Today, (and this is not the first time it happened), I drove maybe 10 miles to break in my new rear gears. So for the cool down period I spent some time at a car wash, about 15 min elapsed and I was on my way back home. Start it up, seemed fine started to pull out and it just fell on its face.
It was misfiring like crazy, but not long enough to set the ses light which is why its so hard to diagnose. The car is basically stock with minor bolt on's like Lt headers, 52 mm bbk and a madz28 tune.Most of the sensors are new, except for the injectors. the opti has 151k on it with a new cap and rotor. If anyone has any clue what the hell is going on don't hesitate to reply.

 

If you washed it and got the opti wet or something else it could be your problem. I relocated my maf and now if I wash the car it will stumble till it drys out. I would have replaced the entire opti unit with that many miles when you did it.

 

well I know not to sray the under side so i couldn't have gotten it wet, i dont think. I know i should have changed the whole opti but money was a issue and since I do my own work I would change it if I need to down the road or when I do a cam swap next winter. on ls1tech someone stated mabe its the icm. I think ill try that out see what happens. anymore ideas lety me know please.

 

If the icm got heat soaked it could cause stumbling. I did the spacer mod and replaced the unit and my problems have never come back. When did it happen before? What was the weather like and how long was it before it happened into your drive?

 

it happens everytime I start the car after its been sitting for 10-15 min after Ive been driving it. Okay.Say, I take it to a store or something... come out a couple mins later and it starts fine, but as soon as I take off it stumbles. It will not do it any other time. only when I restart it after Ive been driving it already.
I also have done the icm mod...I just put the spare icm on and with yet another washer on each side. Ill try it tomorrow and report back.
If this dont work then its opti time.

 

I took it for another long ride, stopped for 10 or so minutes, came back out. I started it (again, seems to start well) started to pull out and it happened again. So, This is after I swapped with a good oem GM icm.

Now, I was just checking things out and I notice underneath my oil cap and in my larger rubber lines there seems to be this yellow goo, smells very strong of gas, it even swelled up the rubber line to the pcv valve and the line from the breather to the throttle body. I think I may have some issues with either the coolant temp sensor to the pcm, 02 sensors or injectors. what do you think !

 

update again....
fuel injectors fixed it.