Help! 1992 C4 Will not always start when hot.

[PhilH]

At wits end my 1992 Vette will not restart if I turn off the engine when it has fully heated up. If I leave it for 20 minutes it will start OK. I have had it in various workshops and they have replaced the starter motor, ignition parts, but the hot start problem still persists. Any ideas please?

 

[LLC5]

At wits end my 1992 Vette will not restart if I turn off the engine when it has fully heated up. If I leave it for 20 minutes it will start OK. I have had it in various workshops and they have replaced the starter motor, ignition parts, but the hot start problem still persists. Any ideas please?

When the problem is active, does the engine crank over and not start, or does the engine not crank over? If the engine won't crank over, then it could be a heat soak issue with the starter solenoid. To verify a bad solenoid you will need to check the voltage at the crank wire (purple) at the starter when the problem is active. Good luck with it.

 

[Antz81]

In addition to above, have you checked for any fault codes?
I had a problem starting my 81 when it was hot and fixing these solved the problem.

 

[Tuna]

Had a similar issue on my old '92 years ago. Turned out to be fuel pressure related - the check valves in the system were allowing the fuel pressure to drop to zero real fast, thus making it hard to restart after it was warm.

Check the fuel pressure to see if it stays pressurized for the required time frame after shut down while you're checking the other items.

 

[PhilH]

At wits end my 1992 Vette will not restart if I turn off the engine when it has fully heated up. If I leave it for 20 minutes it will start OK. I have had it in various workshops and they have replaced the starter motor, ignition parts, but the hot start problem still persists. Any ideas please?

The engine will not crank while it is waiting to cool down. many thanks for the tips so far.
Phil in Oz

 

[Baldie88]

I had a similar issue with my 88. In my case the lights and everything else worked but it would not turn over. Let it sit for 15-20 minutes and it started fine. Frustrating because it didn't do it all the time. Also started fine when cold. In my case, after replacing several relays it was determined to be the starter. Once the starter was replaced I've never had the problem again. You stated that your starter has been replaced so maybe you could have just gotten a bad starter. Anyway just a suggestion. I know how frustrating the no-start can be. I almost didn't do a lap at Indy when the darn thing wouldn't start ad.

Good luck and hope you find the problem.

Ron
"Baldie88"

 

[hcbph]

Nonstarting

The engine will not crank while it is waiting to cool down. many thanks for the tips so far.
Phil in Oz

Sure sounds like the starter is getting heat soaked, been there - done that. Haven't had to deal with it in years but back then there were hi-torque starters that could tolerate the heat better, pricey but they worked.

Something you can also try if you're up to a little rigging. See if you can rig up a heat shield between the exhaust and the starter. You want as much airgap between the starter and the shield as you can safely arrange.

Just did a quick Google search and turned this up: Mr. Gasket Starter Motor Heat Shield 3678: Choose the best Starter -Performance at Advance Auto Parts
If that works it would be alot easier than fabricating your own and at under $30 would be too bad if it didn't work for you.

 

[WhalePirot]

Before going down the same starter road, check the fuel pressure hold, as stated above. It's a quick and easy procedure. The injectors may be leaking into the hot cylinders, not allowing the engine to crank. After a while, the raw gas will seep past the rings and allow it.

BTW, I tried a starter blanket, not a heat shield, and they do a great job of holding the heat IN the starter!

Also ensure that the big wire connections, POS and NEG, are corrosion free and snug. The starter needs every volt.

My mini, gear-driven IMI starter has NO shield from the coated header heat on this 10.5:1 engine.

 

[pete a]

Sure sounds like the starter is getting heat soaked, been there - done that. Haven't had to deal with it in years but back then there were hi-torque starters that could tolerate the heat better, pricey but they worked.

Something you can also try if you're up to a little rigging. See if you can rig up a heat shield between the exhaust and the starter. You want as much airgap between the starter and the shield as you can safely arrange.

Just did a quick Google search and turned this up: Mr. Gasket Starter Motor Heat Shield 3678: Choose the best Starter -Performance at Advance Auto Parts
If that works it would be alot easier than fabricating your own and at under $30 would be too bad if it didn't work for you.

im also having the same problem with my 93,the one difference i have is that for the last month or so i have noticed when i start the car after it has cooled down a little the starter defiantly has a different sound than when starting from cold,so i assumed its my starter ??

thnaks

 

[hcbph]

Starter

im also having the same problem with my 93,the one difference i have is that for the last month or so i have noticed when i start the car after it has cooled down a little the starter defiantly has a different sound than when starting from cold,so i assumed its my starter ??

thnaks

Sounds very suspicious to me. I don't know if there's a way to tell via disassembly if it's a heat issue other than the remote possibility of cooked windings.