Nasty car problem

[rc5]

I have a Pontiac GrandAM 1986 with 115K miles which has develped a weird personality this year. If I drive it continuously for more than two or three hours, it occasionally refuses to start for 15-20 minutes. When I turn the key, that's no starter crunching sound. However, all the lights and radio work. If I leave it alone for 20 minutes, it will start flawlessly. This car has no start problem at all in the morning. Anyone has some clue what could be wrong?

 

[fastz28]

Try a new battery, probably don't have enough juice to turn the engine over. It's cheap and easy.

 

[rc5]

If that's the problem of the battery, why could I restart again after leaving it alone for 20 minute? Even if the voltage is low, I should can hear some sound. There's no sound as far as I could hear.

 

[Viperoni]

The battery is HIGHLY UNLIKELY to be the cause.
I'd say there's a chance that theres a lot of heat buildup under the hood, and it might be affecting the starter solenoid (the thing that makes the clicking sound when your battery IS dead....)

However also check the battery termianls for corrosion (should be part of your regular maintenance plan anyhow! )

I can't really think of anything else....intermittent problem = suckage.

I have a 1986 Parisienne BTW....just slightly bigger than yours...you probably have either a 4.3 or a 5.0 (I have a 5.0 )

 

You are experiancing a common G.M. hot start problem.
The starter is very close to the exhaust system on these cars.
As the starter heats up from the exhaust,the resistance increases in the primary windings in the starter causing hard starting.
The easy fix is to replace the starter with a premium rebuilt or a new one.

Now mind you,this diagnosis is a educated guess because without me actually looking at the vehicle and doing specific resistance testing,I cannot be 100% sure.


Edit
Viperoni beat me to it by 1 minute

 

[Ronstang]

This is definitely a case ofr classic GM starter heatsoak. The starter is old so replace it with a good rebuilt unit and your problem should go away, just as Roger suggests. The fact that it starts after sitting 20 minutes makes me %100 sure this is your problem. I have experienced this problem many times on friend's cars, I don't own any GM cars. IF the problem persists you should look into a remote solenoid modification.