So this car has been a tough one for me because I don't really work on these. The vehicle is a 94 camaro with the 5.7. We replaced within the year, water pump, full tune up including coil and distributor. the car drives fine but after its warmed up, I will take it for a ride to say cvs and shut the car off, go inside come back out and it wont start for 1/2 hour later. After I wait it starts right up. No check engine light comes on. Fuel pressure looks good. Do these have crank sensors? Any advise would be great thank you.

 

When you have a no start something is missing. You need to find out if it dropping fuel or spark or both. I assume you did the fuel pressure while the car would not start?

Simple spark tester are available at parts stores or Harbor freight.

Inline spark tester
https://www.harborfreight.com/90-in-...ker-69023.html
Inductive spark tester
https://www.homedepot.com/p/Lisle-Sp...FZe4yAodW7MOgQ

You will need an injector noid light to check to see if the injectors are being powered.
(verify correct application do not use a test light, it can fry the PCM.)
https://shop.advanceautoparts.com/p/...B&gclsrc=aw.ds

Keep an open mind, just because you recently replaced a part does not mean it can't be bad. I have installed dozens of defective coils, ICMs and PCMs over the years. Most of us warranty mechanics had a stash of known good parts because we knew there was a chance what we got from the parts counter could be defective.

Report back what you find, at some point you may need a scanner.

Just a FYI 20 minute drive then sit for 10 minutes is considered a hot soak. That means the engine compartment is reaching its hottest temp. This is a common point for a weak coil to fail and start running again once it cools. It can also play games with connectors.

 

I would suspect something with the Opti-spark,sounds just like what mine did and I had less than 10K on a new Opti from World Products. Replaced it again and it ran fine. I got screwed because the warranty was out, car sat all winter just after replacement. Good luck with it, they say GM Performance is the only Opti to buy, wish I had bought one.I sold my car right after replacing the Opti again.

 

falure after heatup. coil, fuel pump, ignition control module come to mind. make sure coil wire is pluged in all the way on both ends maybe check ends to see if they look burnt

 

sorry for the delay in response, so i was trying to get the car to stall again and it would not. finally it stalled on a hot day I noticed the car starting to get a little hot and i shut it off and after i shut it off it cranks but no start. replaced ignition control module with no luck. have no spark or fuel pressure.

 

is the pump coming on when key is turned on? can you hear it/

 

check coolant level in the radiator, after its cooled.

 

I am going to check it out tomorrow and see what the coolant level is. Not sure on the fuel pump. So many factors that are throwing me off. It runs normal when its not that hot out, I can have it running for hours and then when its hot out it runs hot and then does not want to start after I shut it off but wont stall unless I shut it off.