View Full Version : Engine just cranks when hot

06-13-2008, 07:09 AM
This sites helped me with a lot thru searches in the past, but I couldn't find anything on it so I though I would seek your guys advice.

I've had this problem for a couple years now. When the cars cold it starts fine, after the cars been at temp for a while (about 20 min or more) and the temp is warm outside the car won't restart unless it sits for 5 to 10 minutes. The starter cranks fine, and if I let off the starter for a split second and try again before the starter can grind it will usually start up, at which point it runs fine. What I have found is that when the engine is cranking the ignition coil does not seem to be getting power. With the key in the on position it gets power, but cuts out at start. So far I have put in a new distributor, coil, plugs, wires, 4 different igniters, and 2 different ignition switches. I also tested continuity among wiring for the coil and igniter and everything seems to be connecting fine. I'm lost on what it could be. Everything seemed like an ignition switch but 2 different ones yield the same results, granted they were both from the junkyard, but I figure atleast one should be good. My next thought is a possible issue with the ECM, maybe a bad solder point that has trouble connecting after a while. I have a few spare ECMs but don't want to go thru the PIA of getting to it and swapping it out until I get some advice from you guys. Thanks

Also..it only does it when the temp is about 70 or above outside. It always seems to stop doing it just before I store the car for the winter. And it doesn't seem to be getting worse i.e. more frequent or having to sit longer before starting.

06-13-2008, 07:43 AM
Sounds like the classic 4th gen starter bug....

Forget how to exactly fix it, but it involves beefing up your wiring, and adding an additional +12 to the starter.

06-13-2008, 08:47 AM
I think it sounds like more of an ignition wiring problem, Tim, he says the starter cranks fine.

I'd still suspect the ignition switch from what you're describing. Since you seem pretty familiar with testing wires, here's what I'd do; Remove the column cover and test the ignition switch harness directly as you turn the key. Hook a test light up to the black and orange wire. Here's what it should do:

Key at ACC: No power
Key at ON/IGN: Power
Key at STR/Start: Power

It sounds like that connection is loosing power when you turn the switch to start, which it shouldn't. The accessory line is disconnected when you turn to start in order to boost power, but the IGN line should be hot at start up.

Just to be clear, did you get the actual ignition switch (which includes the wiring harness), or just the lock cylinder?

Edit: You know what, if the above condition were present it wouldn't start ever, not just when hot. I may as well leave the post in case it helps anyone else, though. You've got a weird problem, man!

06-13-2008, 09:06 AM
Check the coil, sometimes if a coil overheats it'll stop working... usually it'll just stop working all together but this does happen.

06-13-2008, 03:57 PM
I agree with n0c3l1. I had the same problem on my 5th gen. When it is warm outside or my engine has gotten hot, I will get the same symtoms as you. If I left it in the "ON" position to listen to the radio and try to start it, it will not start. I cleaned out the wires and placed a heavy duty ground wire from the starter to a nice metal to metal ground. Solved the problem. My starter also turned in the same fashion as yours did. First step is to clean the wires (positive and negative). Follow the negative wire and replace with a thicker gauge wire and sand the part where it connects to the chassis.