86 crown Vic when hot turns over like a dead battery, after 20 mins starts great.Whats wrong?

Answer 1

sounds like what the old chevy's used to do, it's called heat soak and that is when your exhaust manifold is so close to the starter that the starter gets too hot and doesn't function properly until it cools down.

Answer 2

1.) - not as likely as the cooldown period is normally longer - the starter could be loosing its insulation or ground because of heat (normally a V8 starter does NOT loose that much heat because it is tied to the block and very close to the exhaust).

2.) Timing problem - in either the computer system OR the bypass; is (was) taken out so the timing could be changed by hand (it was not replaced, or the computer timing is messed up so it was left out) - this is a very common problem with the spark is set too far advanced, more rare however on semi-electronic controlled systems.

3.) Stuck fuel injector - the (a) fuel injector is stuck allowing the pressure on the system to bleeddown into the intake making the fuel mix WAY too rich - over the 'time' the fuel evaporates very quickly from heat.

Fixes: (other than taking it to a shop)
1.) Take the starter to an autoparts store and get it tested - remember these tests are relative.

2.) Find the spark control bypass plug (normally a yellow plug with two wires and a plastic 'dongle' that plugs into the socket - Normally it is very close to the distributor wiring harness) - if it is missing replace it --- if it is there then remove it and set the timing to factory specs, then replace it.

3.) IF you have TPI you cannot test it yourself / on throttle body injection, take off the breather (watch the hoses) run the car till good and warm (you should see the injectors spraying a cone of fuel), then shut the car off and watch for drips of gas from the injectors; one or two small drips is nothing to worry about.

Answer 3

Failing starter, bad cables and / or connections.
After the engine sits for a few minutes, the compression already present leaks down a bit, and the expanded engine parts cool a bit allowing for a little less friction.
Best bet, ask that the starter draw be tested, as well as battery condition and connections.
While you are at it, it takes only another 5 minutes to do a complete charging and starting system check. Then you can get an estimate of repair as well.
If you are planning on a do-it-yerself repair, start at the terminals, then starter.

Good Luck

Answer 4

Actually, the older Fords had a few issues with thier coils. I have had a few and had this problem as well. Seems that after the car has been running for a while the ignition coil begins to break down because of heat. So, after the coil cools down, it will restart. Pretty easy and cheap fix.

Answer 5

Your engine block is somehow overheating. Could be thermostat or something as easy as a pcv valve. When it's hot, it diesels. That is an industry term meaning the cylinders are so hot, they ignite the gas without a spark. Bad news. Could be many things, valves need to be re seated, who knows. It is an 86 crown vic, so you are lucky it still runs at all.

Answer 6

I had a GMC Suburban that did the same thing. Discovered the starter was getting too hot when towing. Had to buy a aftermarket high torque, high performance starter to cure the problem.

http://www.actionspeedparts.com/high~torque~starters.php

Answer 7

Had the same thing w/ my Mercedes ML 320. It was the Crank Position Sensor.

Many mechanics told me it was the starter (even those in here) but the shop said it was this crank thingy.

Good luck.

Answer 8

Check your starter amp draw - and check all connections to your battery, and starter , that should have a starter soliniod - make sure if you replace starter you change that with it.

Answer 9

look first to replacing the starter

Answer 10

starter windings are going bad...replace the starter