chris_gray101

Rossi-
I spoke with my father about your problem, too... Not sure where you are at with it, but he thinks yours might be related to a "cooling sensor" of some sort. Almost like its registering not as cold outside as it actually is, so in response, it's not sending the extra fuel it needs to start in colder weather. He thinks yours is simply running to lean... does it run fine after the engine warms up? Not sure if this helps, but that was his thoughts. I figure any suggestions help!

tansupercrew

Walt, it sounds like your relay is failing. It's a continuous on relay so it either works or it doesn't. It's rare for the relay to fail in the middle of functioning. If you don't want to just replace it, just use two paper clips to substitute the relay when it won't start. I will look at the diagram and tell you the pin numbers

tansupercrew

Ehh, it doesn't say but it's a 4 leg relay so two legs will be hot with the key on and two will not. just jump the two hots to the two nots and the pump should run. Keep in mind the pump will only get power from the second leg for about 5 seconds in the accessory key position.

chris_gray101

We thought the same thing about mine (similar issue)... But it wasn't. All the relays are the same, so we switched them... Nothing. Then rigged up a fancy homemade tester to jump legs. That's not it either... Think the relay is fine on mine. (Please see earlier posts)... Do those fuel rails have screens in them? Or something that could clog easily?

Mikesavage

I have a 1999 f150 and I am experiencing a similar problem except my truck starts when cold but once it warms up or recently when it sat in the sun, it won't start. It has been happening on an doff for a couple of years but only in the summer. it works fine during the colder months. I usually just keep it running when it is warm out except today, I left it running then it stalled out and it won't start at all. Was originally looking at a crankshaft sensor. Has anyone experienced this problem?

76tiger

Just had a very similar issue that is now resolved.

What does your odometer have on it when it does not start?

All Dashes on the OD when the no start happens and a theft light blinking rapidly?

This may be a PCM issue.

Regards

PT

TRD-Toy

I would back probe the fuel pump wiring when it won't run the pump. You may be getting power but no ground. There is also a connector by the air box which the fuel pump wiring goes through may want to check that connector too. Look for the bigger wires that feed the pump. Yellow or pink can't remember. Had a F150 at work kept popping the pump fuse. Found customers CAI filter rubbing on the wires. Filter was metal so direct short to ground. He was on his fifth pump. I would try a relay first. If still a problem, back probe the relay and see if the PCM is giving you a good ground at the relay. The relay should have 1 constant power. 1 keyed power. 1 ground from the PCM and the load.