Turns over but will not start

KBC14

MEMBER
1986 FORD F-150
4.0L
4 CYL
4WD
AUTOMATIC
100,000 MILES

Try to crank my truck and it turns over but will not crank. I have replaced just about everything I can think of. I hooked up to check fuel pressure and that's not the problem. But if I spray gas in motor then it will crank and drive but then it acts like it doesn't wont to pull after driving for a minute. I've replaced coil, map, ignition switch. I don't what's wrong with it. I've even changed the computer.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,383 POSTS

Welcome to 2CarPros.

If it starts with starting fluid and remains running but you notice a loss in power,it may be related to the engine coolant temp sensor. For engine control applications, the ECT signal is used to modify ignition timing, EGR flow, and air to fuel ratio as a function of engine coolant temperature. The reason I'm questioning this is because of the start conditions you described and driveability issues once started. If the fuel pump is to spec, this would be the first thing I would suspect.

What I would do is check if there are diagnostic trouble codes stored. Here is a link that explains how to do it on an OBD1 system:

https://www.2carpros.com/articles/ford-lincoln-mercury-obd1-1995-and-earlier-diagnostic-trouble-code-definition-and-retrieval

Do this and let me know the results. Also, let me know if you have other questions. Also, let me know the correct engine size. Is it a 4.9, a 5.0, or 5.8?

Take care,
Joe