PollyRDH98

Recently bought my son a 1990 F150, 8cyl, 5.0, Ext cab, AT. It needed general maintenance, plus valve cover gaskets replaced. We changed the oil, purchased the gaskets, plugs and wires and a throttle position sensor because of issues with the truck stalling out when he would put it in gear and start to drive.

Before we got around to changing the gaskets, plugs and wires, he was driving home last week and the truck died. Completely dead as a doornail. Had battery and alternator tested, both tested fine, so we took out the starter and it was bad. Changed starter and solenoid, and all seemed fine again (Sunday evening).

Yesterday (Monday) morning, he was driving to school and the truck kept stalling on him while driving. He would pull over, and it would start right back up. Since we already had the TPS, we installed it last night, cleaned the throttle body, changed the air filter, and replaced a couple of hoses that were dry rotted. (Also disconnected the battery ground, as I've read, to reset the computer.) After getting it all back together, the engine ran like never before, but the transmission jumped a bit when shifting. We drove for several miles to make sure it wasn't going to stall out again.

This morning, it wouldn't start. Engine turns over, but won't start. I had already left for work, so I wasn't there when he tried to start it, but I listened on the phone and the engine was just spinning. I do want to check the wires when I get home to make sure I didn't bump one when I was removing the throttle body, but last night there was no hesitation when starting it.

I wanted to change the plugs and wires last night, but didn't because we got done with the throttle project so late. Will probably start by changing them this afternoon. Anyone have any other ideas? Possibly the ignition switch?

Still have to get around to changing out the valve cover gaskets but I think that's a project for my son and his dad.

Thanks for any help!

jcm278

Fuel pump and fuel filter check em. buddys truck wouldnt started new fuel pump and that things running finer than ever

Good old Bill

Check for spark at spark plugs, and check for fuel at fuel rail. (depresss schraeder valve).

PollyRDH98

Thanks guys. Sounds like the fuel pump is kicking on when we turn the key. Went and bought a fuel filter and was getting ready to change it when one of our Florida thunderstorms blew through. Going to have to get on it tomorrow. Will also be able to change the plugs and wires tomorrow too. Hopefully that will help. Will let you know.

PollyRDH98

Changed spark plugs and wires and fuel filter. Still won't start. Looks like I'm going to have to have it towed to get it figured out. Possibly fuel pump, but I think that's over my head.

66719

might try checking the fuse box under the hood on driver side, Mine 96f150 blew a 20 amp fuse don't know why still checking but changing the fuse fixed mine.

Warlockk

Always do your basic checks first. No point in random parts replacement. Check for fuel pumping. A broken fuel pump can still spin without sending fuel. Check for spark at the coil and plugs. Check base timing. Compression is likely ok because the car was running but it couldn't hurt. And test for vacuum. And check for codes. If you have air fuel spark compression and timing is somewhere close the engine will run so figure out wich isn't there and we can start tracing systems.

Good old Bill

Hey Warlockk, its good to see people actually remember the four basic requirements needed for an internal combustion engine. You added a fifth item, timing, and rightfully so, engines don't run if timed to exhaust stroke. Been there and done that. A rookie swrew up that we all have done at least once.

Warlockk

Thanks Bill it seems the more we learn and the more tools we have the more we forget the basics. Many good technicians have wasted unpaid hours with computers and replacement parts just to find a power wire or vacuum line loose. Things that should show up in your preliminary inspection.

southernyankey1

Check for error codes. Might be the cpu on the way out. My '90 did that and it drove me nuts... Intermitttent auto shutoff feature!!! lol. I kept replacing parts and it would run fine,then die...I even broke down and ashamedly towed it to the local ford Dealership in utter defeat where the resident Master ASE (22 year old..haha.. told me it was my fault for not using genuine FoMoCo parts and also that he couldn't figure out how to turn off the high beams(I SWEAR THAT'S WHAT HE SAID!!!) and it would be 700 plus dollars to fix what I had already FIXED! he said I messed it up so badly that the codes were changing all the time so I took my keys and towed it home and replaced the cpu for 90 bucks....Been running perfect ever since.
Off topic but I've been dying for an excuse to tell that story!!!
Genius couldn't find the floor dimmer and inadvertently told me what the real issue was without knowing it...LMAO. too funny