So the Lt1 in my 94 vette is presenting a rough start /no start issue when warmed up to closed loop.
There are no codes.
4 years ago I replaced the ICM as it had a code 16. That fixed it right away.

Without a code im a little lost on diagnosis. So far I have checked the fuel injectors, all seem good and I have normal fuel pressure.

I am thinking I have an EGR issue, a MAF issue or the ICM and Coil are on the way out.

I dont think its the opti as it starts and runs/idles fine until its warm.

Thoughts?

Sounds 100% like icm heatsoak condition. Mine had the same issue once it warmed up it cut out and not start untill it cooled off. I placed a couple washers in behind the icm/coil bracket to let it help cool faster. Issue went away. Only other option I can think of would be if the rotor screws in the opti are starting to loosen up. When it warms up the rotors loosen and once it cools down the screws tighten. Not likely but anything is possible.

If you have a scanner that shows data check the coolant temp when it acts up. Seen many fail and over fuel

Thats another one i forgot to think of. Check the wiring to see if its chaffed going to the plug its pretty common to see.

Un plug the maf and try. If it runs pretty decent well.. maf gone. If that dont work I spray some fuel directly through the TB and have a guy crank/pedal to see if it runs okay with manual fuellng as i keep squirting before I start digging checking plugs, compression and whatnot. Just be careful with this method. Fire = bad definitely an outside job with fire safety on hand and a safety action plan before you go right? Right.

For a squirter and old empty 1L oil jug works mint. I drill a small 1/6" hole through the cap and gasket and fill it 1/2 way or so. Then cap it and squeeze directly at blades while the engines cranking/running and someone pedaling this will run it for 30 seconds or better. You can flood it out easy so listen to the engine and give it what it wants. Anyways I could go on and on

Well I havent had any time to work on the car. I would like to purchase an OBD 1 scan tool/real time data. ANyone have any suggestions with what to buy? Or is an ADLD cable plus the various software available online a better route?

Here is a link to free scanning software. Just need a cable and laptop to use it.

http://www.camaroz28.com/forums/lt1-bas ... rs-874325/