Howdy, I'm having a major issue with my truck. It's an '89 F150 XLT Lariat with the 5.0L 302 in it, 2WD. After all the years it's still a great truck, but now I'm running into an issue that I can't seem to figure out. Months ago I had this problem where the truck would randomly shut off, and it wouldn't start again until I guess it cooled off or somethin. Make a long story short I replaced the EEC relay and it worked great for months, didn't have an issue after that. Now I'm having a similar issue but another EEC relay didn't fix it this time. Now sometimes it stalls, while driving or idling, it sputters, sometimes it picks back up and sometimes it just dies out. It seems like something is either getting too hot or shorting out or somethin. I used to could make it to work and back, as the truck would sit for 10+ hours without running, now I can't even make it to work, and it's only a 30 mile drive. Whenever it shuts off, it'll turn over all day long, just won't crank up. Seems like I gotta wait anywhere from 15 minutes to an hour or longer for it to "cool off" or whatever it's doin before I can start it again. In the past month it's left me on the side of the road probably over 10 times. Here's what I've done so far thinking it could have something to do with the problem, but still nothing different: I've changed the EEC relay again, the ignition coil, the fuel filter, can't remember if that's all I've done personally or not. I think this weekend I'll try a full tune up, see if that helps. I might also try a fuel pump relay.

I love this truck and want to see it back to runnin great, if anybody can help out that would be awesome. Thank you.

 

do you have spark/fuel pressure/

 

When I push down on the valve on the fuel rail it's off and on, sometimes I get a steady stream sometimes it just pisses out then trickles.

 

Fuel pressure regulator. Unhook it and see if it starts.

 

Alright, so started it, waited for it to stall out, unplugged the regulator and it cranked right up. Also while its running it sounds like it runs smoother with it unplugged. Guess I should change the regulator next?

 

When you disconnected the vacuum line at the regulator, was fuel present? Should be no fuel in the vacuum chamber.

 

I didn't smell or see any, no.

 

I had a similar problem not too long ago, we replaced the EGR valve and the O2 sensor which helped. My problem was that the engine kept flooding when i would get on the accelerator. This fixed the problem mostly. Then we replaced the Fuel pressure regulator and the throttle position sensor. Its running like a champ now! Dont know if this'll help, but you could look into it.

 

Thanks man I'll check em out. I appreciate all the help folks, glad I've been sent in the right direction finally.