1990 e 150 300 6cyl.78,000 mi Will crank but won't start. This started over the last two weeks about 6 times. Will crank and crank no start, let sit 5 minutes and starts with no problem, not flooded and no black smoke runs great. Starting to get concerned as it is happening more and more, died today in traffic. Pulled to the side waited 5 minutes and started no problem. Usually catches right away however it is becoming harder (cranking more) to start. What should I look for first?

 

I place my bet on the Fuel Pump/sensor.

We went through the very same thing a couple of weeks ago with my husband's 83 E150 EFI/302 Had to replace it after it died several times while in town. The constant cranking over was the first symptom.

However, you might want to look at the starter/solenoid too.

 

I have tried the simple things first, deactivation switch is Ok, Getting spark, now it won't start at all. How do I test or look for starter motor relays or fuel pump sensors?

 

When it is acting like this, you just replace it. It's gone.
At least that is what we did. Messing with computer pads to check sensor readings is something my husband refuses to do.

 

carry a timing light. Next time it does this, attach it and check for spark. also, when you turn the key to on, check for fuel pump "whine".

If you have a fuel pressure gauge, you can see if there is any pressure in the fuel rail.

check the codes just to see if there are any logged.

 

Hey I got it! You guys give just enough help to give me the confidence to look at what may be it to solve the problem. The lead for the fuel pump had a bad conection at the starter solenoid. Seems to run great! I have been putting off that gas smell which I think is the rear tank and the front tank drips some gas when I use it so one at a time and see what happens. Thanks Again Vikingbabe and Mustang 5.0.

 

Anytime! Glad to know it runs fine now