1999 XLT 4.0 113,000 miles. Truck ran fine yesterday when parked. Get in this morning to go to work, starter cranks and cranks but engine will not fire up. Cranking sounds normal like always. I let the truck sit for about 10 minutes, go back out and it fire rights up. Never had this problem before.

I am thinking fuel pump? Possibly ingnition coil?

Any ideas? How do I diagnose this problem if it happens again? I guess I would start by pulling a plug and checking for spark while cranking.

 

Yeah, but before you go that far, simply listen for the fuel pump when you turn the key to run, without cranking.

 

+1 give your fuel pump a little time to cut on before trying to crank

 

Thanks guys...I will do that later. I feel stupid not thinking of that at the time.

So this sounds indicitive of a bad fuel pump moreso than a bad fuel pump relay or fuel system wiring problem?

 

have you changed fuel filter recently. I had same problem a few weeks ago after I changed fuel filter found out I was leaking a little gas but the lines were tight on the filter after it was changed. Changed fuel filter again stop leaking and figured out that on the the ends on the filter was slightly larger.

 

Negative on changing the fuel filter. Truck seems fine now and I have done nothing to it.

Why would this only be a problem one time?

 

Maybe your truck forgot what it's doing. You know had a brain fart......lol

 

Mine has done a similar thing. Would start fine most of the time. Sometimes would "hit" a couple of times and quit. Would not start for a while. Then was fine a couple of hours later. Replaced the fuel pump relay, and presto, it works every time again. Still doesn't make sense to me though, as it worked some times.

Tim Glover

 

UPDATE...

I haven't had this this problem since.

Crazy, huh?

 

yeah, that does seem kinda strange...

 

Could have been a piece of debris in the pump.

When something like this happens I always turn the ignition on / off / on just to cycle the pump.

Rich

 

This happened to my roomates ranger a few weeks ago. She was cranking for a while, at 5am... I think it was just a fluke. another thing to look into is the fuel pressure regulator. If that was going out, it would cause the fuel rail to loose pressure making it difficult to start. However, if you were getting any pressure from the pump it should take a few cranks to start up at the most.

 

Mine does that everyone once in a great while.