Good morning everyone, and Happy Thanksgiving to my other fellow Canadians!

I'm having some issues with my 1986 F150 that I am at my wits end trying to figure out. To start, its a 1986 F150 XLT, 4x4, 302 (5.0L) EFI, Auto trans, with 110,000KM (68350MI) on it.

The past few days I've been in the shop working away at replacing both valve cover gaskets, upper and lower intake manifold gaskets, replacing spark plugs, wires and cleaning up the rotor and cap, and giving as good of a cleaning as I can do.

So now that its all back together, it fired right up, and purred away while sitting in the shop, and had no issues while I drove it around the compound to warm it up. As soon as I closed up and started driving it home, the truck just died, and wont start again. No coughing or sputtering, the only way I noticed was just because I stopped accelerating. Lights didnt dim, and the radio didnt die, it just stopped running. Now it wont start again. It'll crank and crank and crank, and every once in a while it'll want to catch, but nothing.

At this point, I'm completely lost, and starting to get stressed out because I can't figure out where, or what I'm supposted to be looking at! So any help would be greatly appreciated!!

Cheers!

 

I had a similar issue once. A wire had rubbed on the frame and would ground out. The truck would die just like you flipped a light switch off.

 

I've had the unfortunate luck of this happening to me also.

For me it was a bad ground with the DSII system. Engine just shut off. Lights were still on, radio still going, just like you describe. It wasn't grounding properly through the distributor. Spliced into the ground wire from the Ignition Control Module to the dizzy and grounded it to the frame. Haven't had it happen since.

Hope this helps.

 

TFI on the distributor?
Will it run if you pull the spout plug?

Why don't you ask the computer what is wrong?
There are instructions on the web for pulling codes from OBD1 vehicles.

 

Thanks for the suggestions! Once I'm able to convince someone to help me tow it inside I'll check those! Its super rainiy and windy out and have zero motivation right now to do it in that weather! But while I wait I'll look up how to check codes!

 

Hauled the truck back into the shop. Can't find any grounded out circuts, and all the connections are solid. Did however get it to fire over, but wouldnt run. So now I'm leaning more towards the timing of it??

 

Ignition timing is controlled by the computer... pull the codes to see what the computer thinks is happening.

Like the other guys, I suspect a crimped wire/bad connection/something similar in the distributor area....

 

If it will run (in limp home) with the spout removed the fault is in the computer.
If it won't then the fault is in the pip or tfi at the distributor.

 

So I've been combing over the truck, and checking different things. And I think I'm ready to agree with you guys! So I've checked the ground and it seems to be working fine, but I'm going to swap in another distributor to see if that gives me any better results. So far I've been able to get it to fire up and run, but with the throttle as wide open as it'll go before it goes into the flood shut off range (wide open). It'll run, but barely and at a really low grumble... With my work schedule I'm only able to pick away at it now, but hopefully I've started narrowing things down now!

 

Not really enough info here to even suspect an electrical problem. Engine does not run? Compression, fuel or ignition. Which one is missing? The fact you did get it running suggests the ignition or anything else electrical is likely working. I would suspect a fuel delivery problem, possibly a failing fuel pump. Check the fuel pressure at the rail with a gauge. No shortcuts! Also check codes as has been suggested. If there is something wrong, the system will flag it.

 

Thanks for your input! As far as I can tell, all 5 components are there. I checked the fuel pressure at the rail, and even hauled the injectors out and cranked it over, and trust me, theres fuel! Haha! It has good compression, is getting air, TPS works, and am getting a nice bright blue spark when the plug is out of the cylinder. Ive checked and retimed it, and thats proper. Wires on the cap are in the correct order, and so far I haven't been able to find any sort of short in the wiring, and no codes are coming up either.... So now I'm entering the stage that I'm running out of things to look at. Maybe a faulty inertia switch or something?

 

The computer will be giving you a Code 11 if all is OK. The inertia switch cuts power to the fuel pump.

 

Good to know! So that would mean the inertia switch is fine. I'll try checking the codes again and see if I can pull anything up. Even if I have to take a video of it! Haha!

 

Have you checked for injector pulse with a noid light?
Is the computer ground (up by the battery) clean and tight?