My car won't start after it has been driven for 20-30 minutes. I don't have a clue what would be causing this. I thought it might be the battery, but it starts the first turn of the key after it has been sitting for 20 mins. The engine gauges in my car work and show that my car is not over heating and that there is some charge on the battery around 10-12. If you have any ideas, please help me out.

 

heat soaked starter?

 

Explain what you mean by heat soaked starter. I had a friend tell me that my starter may be too close to the headers. If that is what you are talking about, how would I be able to fix that problem. The weird thing is that I can jump my car off when it is hot though.

 

I will bet you ten to one it's your ignition module. Those things are prone to going bad in all Fords. It is a little module that is only about $30 and sits on the distributor. When they are going bad they will cause the car to not start when hot. Once they go completely bad the car won't start at all. I have gone through two of them since getting my 5.0 last year. Granted the second one was my fault b/c I forgot to put silicone on the back of it before installing. The silicone acts as a heat shield to make it last longer.
Changing the ignition module is very easy and if you are having trouble unbolting it then just losten the bolt that holds the distributor in so that you can turn the distrubutor to get at it. Before you do this make a little mark with chalk so you know where to line it back up before tightening the bolt back down.

 

Do you have larger injectors? If so, put the gas pedal to the floor while you're cranking it over. If you run the stock computer with larger injectors more often than not you're getting WAY more fuel than you need on start-up when it is warmed up. When you put the gas pedal to the floor this essentially cuts off the injectors momentarily, allowing the engine to fire off easier.

 

I will definitely have to try a new ignition module because what you described sounds like what my car is doing. Thanks for the suggestion.

As far as injectors go, they are not larger injectors. But before I bought the car the engine had been rebuilt about a year before I got it with a few modifications to it. The person I bought it from had over reved the engine come to find out, so I had to tear it down and replace some stuff and put it all back together and in. It has a K&N air filter system, a new 89 computer put in it, new alluminum headers, flowmaster pipes, and new piston heads after it was bored 30 over. Now the whole engine is basically brand new.

 

definitely sounds like the ignition module. had the same problem on my 86 and 90

heres a pic just incase. its a 5 minute job tops. and are around 25-30 bucks

 

Just make sure when you do it you apply a coat of silicone to the backing. It's the part that touches the distributor. Without it the module won't last more than a few months. Most auto parts places will give you some silicone with the module.

 

starter solenoid or the starter.

 

out of 6 mustangs, I have had to replace starters in 3 and starter solenoids in 4