okay guys please help me!... I had a problem where my car wouldnt start when it was at operating temp. so, i did the normal route and replaced the icm. It worked fine, then 2 days later, it started again. i would start it up, it would run fine, then i would pull into the driveway, shut it off, and immediately try and start it again, and nothing! what is going on!? i waited like 3 hours, went out, and it started up. can anyone help me? i need some input on what could be causing this problem

 

When you attempt a hot start, what happens?
Does eng crank over but not start?
Does it just make a click sound?
Does it not do anything?

 

Dude mine is doing the exact samething. Same year 89 5.7 stock auto. At first it would start right up,, then after it would get hot,,, start idling ruff and lose power. My mechanic said it was the fuel pump so I replaced it myself(nightmare getting the tank out). Okay now no more idling problems or power loss, but AGAIN wont start once its hot!!!! Now I heard the injectors and fuel press regulator are bad too.... but at this point I'm pissed. Cause with these cars its always a guessing GAME!!! Let me know what you come up with man, Good luck!

 

It doesn't have to be a guessing game. Look at the post above yours and ask yourself those questions. Is the engine not turning over, are you not getting fuel? Go from there.

 

Easier said then done. Yes it cranks like it wants to start, but nothing. I've been told I need new fuel pump and injectors and it should run fine! Fuel pump- did that,, now its the injectors. MONEY MONEY MONEY.. and yes it probably wont start again!!!

 

yep, my car will crank over and not start, and sometimes i will be driving along, and bamm, the engine just dies out. i take off the cap, fiddle with my icm, and she starts again, i dont get it, i have all good connections, and a brand new icm, do i need to reprogram my ecm or something? im so sick of this! is anyone located in massachusetts? i really need to have another brain working with me....

 

My guess a couple of things (BTW, this should be in the TPI forum), but did you put the gease undr the control module when you changed it?

Can you ohm out the pickup coil? (should be right at 800 ohms, plus/minus 30 or so)

Look at the PU coil and control module connector...any green/crud there?

If so, replace'em.

 

Check your injectors...I had to replace all of mine... I still have a starter heat soak problem but it does run from a to b now...

 

i have checked all my connections, and i have a brand new coil, all are good, and yes i put the thermal grease under the icm, i just cant understand whats going on, and it also cant hold at idle, i wish i knew how to reprogram the ecm, but thats way over my head

 

Have u checked fuel pressure at the front end?
Fuel pump relay? ($10 to find out with 30 second install , worth a shot?)

With other cars all my hot start problems were related to broken ignition wires...I know u prob have good ones and that'd be too easy but sometimes it's the most obvious things we cannot see!
good luck!!
----------
PS - Surely it is giving you codes of some kind for a clue??

 

well i have finally broken down and brought it to a mechanic, and he thinks my valves may need adjusting, that should take care of my rough idle, but the hot start is electrical related he says, and he will chase it down to find a solution, i will keep you updated. it sucks because i spent sooooo much money to get the car to look beautifull, at the expense of my engine running beautifully, so i will have to throw money at it untill it runs as good as it looks

 

Any luck yet?? Dude I'm going to replace my injectors soon. I was told by my mechanics that they are bad. I read somewhere that the 89 rocs are known for injector problems. Have your guys check em out..... later bro

 

Just thought I'd chime in here.
Just completeing a speed density TPI swap and I had the exact problem. Cars starts and runs fine. Then after warm if you shut it off it wouldn't resart, it would crank but thats it . Ended up i had not seen a cut wire for my temp sensor in the pass side head. I know this sensor is used by the ecm for fan control ut apperently its used for something else. Maybe you chould check that sensor
Just my

 

had the same issue with my 95 tbird i sold, replaced everything to no avail, finally put a new used distributor in there and it stopped completely. i believe its the pickup coils that go bad.