Alright you geniuses of the gears, here's a lil riddle for you...

What would make an 87 F-150 4.9 I6 4x4, suddenly sputter and die, and then fail to start. The motor turned over, and seemed to partially fire, but never a complete start. I suspected fuel-supply was the culprit, so I put gas in both tanks, but still she wouldn't start. Had my GF crank the motor while I crawled underneath and whacked on the tank with a hammer to see if the fuel-pump was failing.. nothing. After an hour futzin around on the side of the rt 202 expressway, I called AAA and had 'er towed to my mechanics. I explained the problem to my mechanic and he had me go try and start it then. Sumbitch fired right up. Ran off both tanks just fine. Turned it off, and fired it up again just fine. Neither of us is sure what could have caused it, so I figured I'ld drop this one on you to see if I can mebbe help him diagnose the prollem.

Just a lil background, this truck has sat for the better part of 6 years, though both tanks have relatively new-ish gas in em. The frame-mount fuel filter has been replaced, as have most of the ignition and computer components.

Whatcha'all got??

The Admiral

 

Hi pressure fuel pump, eec and or fuel pump relays, could be a hundred things.
Have you checked for any codes as the 87 may or may not have had a check engine light. Most didn't.

 

I know he plans to plug the truck in and check the codes tomorrow. I believe the "check engine" light in my 87 is actually just a red "Engine" light, and it did come on when the truck was dying, and then would come on when I first tried to start the truck on the roadside. I just assumed it was comming on as part of the standard startup sequence.


The Admiral

 

Dear admiral space lord.
I am the Admiral, you are now demoted to vice admiral. ...
haha.

Anyways.

Rust in the injectors or something wierd coulda caused a hickup till it was moved and it broke free.
one of the igintion wires coulda been fged up. Or even coil or something similar not operateing properly.
Lots of causes.

Now beam me up!

 

Aliens.. trust me

 

If it was rust etc in an injector, am I gonna have to pull em all and clean em to make sure this doesn't happen again?

As fer bein Vice Admiral, around here I can take that hehe They call me the Admiral round my neck of the woods, based on a comic book character I once inspired. (picture in my gallery if yer bored)

I'll let y'all know what my mechanic finds out tomorrow, and I'll suggest he check the relays and injectors as well as the codes.

 

The red "ENGINE" light just comes on when the oil pressure is low to alert you to look at the gauges. The "Check Engine" is probably not wired to the computer...my 87 was not.

 

Coolant temp. sensor or wiring to it???I've heard of them causing a no start when hot then starting when cold and acting up again when hot etc. etc.

 

Damn he's good. So my mechanic finished fixin the truck. Needed a new Ignition Control Module (?), which explains the rough idle Ive felt the last 2 weeks or so, and traced the shut-off problem to the wiring on the on the fuel pum relays, whcih is in line with what Popa Tim said above. As an added bonus, he's going to fix the exhaust leak in the y-pipe for me tomorrow. Yee-haw!!

Thanks for your suggestions fellars. Much appreciated.

The Admiral

 

had same problem last year. it was definitely control module not cheap but first culplit was thought to be fuel pumps glad i difdn't have to replace them at 350. per

 

Actually, the fuel pumps w/sending units are only bout 160 a peice on LMCtruck.com. I was considerin replacing them in the spring when I take the body off to clean up the frame rails and replace the bed-bushings.

The truck still has a rough idle.. a very slight one. at this point, Im pretty sure at this point, that just finally doin the tune-up, should clear it up.


The Admiral

 

you must have a lot of room to take the body off and clean the rails. fortunately the only big project i got ahead is new muffler mounts that rusted off. i'll look into lmctruck
thanks