Hi, I recently got my 1983 F250 7.5L out for the summer and ran it down the road and it ran really good. But when I went to drive it after putting insurance and plates on it, it would only run for thirty or forty seconds at idle then die. I had this same problem last year at this time and found out it was an oil pressure switch. I replaced it and it fixed the problem. I text the oil pressures switch by completing the circuit with a bypass wire but still the same problem. What could it be? I appreciate any feedback.

 

I tested it again this year**

 

I'm not an expert on this, or anything for that matter, so I'll stick to giving you a link to the schematics and troubleshooting info from the EVTM: Electric Fuel Pump Control - Gary's Garagemahal. Hopefully those who are the experts will be along soon.

 

Thank you for the link!

 

"[Quote]: I recently got my 1983 F250 7.5L out for the summer"
This may sound elementary but....from your description, the truck was stored during the winter months ?
If so, did you use a fuel stabilizer ? Sounds like once you drove the truck... sediment in the tank was stirred up possibly causing an occlusion. Moisture in the tank may be playing a part also depending on the storage environment. Fuel filter replacement ? Today's fuels do not take well to extended storage. I go through a regimen every fall with my "lead reliant", older cars as well as my Ford 8N tractor for the winter months.
Dry Gas/Fuel Stabilizer/Lead Additive .....run for 30 minutes...done.

 

[QUOTE=WhatsAChevy?;16264788]"I put new gas in it. I also used storall during the winter. It will run great for thirty seconds so bad fuel doesn't really sound like the problem.

 

30 seconds sounds like about what you'd get if the fuel pump only ran during starting, filling the bowl and then it runs out. So, I'd put the volt meter on the fuel pump and see what's happening. Or, put your hand on it and see when it runs.

 

Inspect fusible links at starter solenoid to see if they're burned or something chewed on them.

Check inertia switch on passenger side kick panel if it's popped, re-set it.

Check to see if the (yellow I think) wire has got power at the fuel pump relay all the time. This is the wire that runs through the 20 gauge fusible link attached to the big lug of your starter solenoid then through the inertia switch, to the fuel pump relay.

Check your fuses. IIRC fuse #18 is a 15 amp fuse and with the key on it sends power to the oil pressure switch and when that switch closes power goes to the pull down side of the fuel pump relay, completing the circuit and allowing power to flow through to the pumps.

 

Thanks for the help guys! I will go through the steps you guys said and see what I find!

 

I checked all the fuses and they are good. I also checked the solenoid and everything looks good with the test light. I also have constant power in the yellow cable going to the fuel pump relay. The fuel pump doesn't feel to be kicking on either when I hold my hand on it and it's running. What next?

 

And the shut off wasn't triggered.

 

Is this one of those trucks with two fuel pumps? One low-pressure pump inside the tank and a high-pressure variant closer to the engine? Probably not, because 1983 would be carburetor (= low-pressure only).

A 1983 F250 with a 460... and you have an electric fuel pump? Is that factory? Could be, I guess.

Regardless... I'm surprised I didn't see this in Gary's EVTM... but if you are confident the pump is getting electrical power when it should, your pump may be on its way out; what they have you do is put an ohm meter on the two power leads for the pump and check for continuity, no connection = burnt-out motor.

But go back to basics... when it dies, go check for both fuel and spark...

 

Where is your fuel pump, that you can touch it???

Do you have power coming OUT of the fuel pump relay when the oil pressure switch is jumpered and ignition on?

 

Thanks for the help guys got er fixed!

 

We like to learn, so what was the problem?