Hi,

I just finished replacing the ignition actuator in my friends 1987 F250. The repair was done from a good write-up and I didn't have any problems along the way.

I also replaced the ignition switch and the ignition key/lock tumbler.

Now the truck tries to start but won't stay running. When I pour a bit of gas in the carb the truck starts to run but then kills right away.

One bonehead thing I did I left the battery connected overnight with the keylock tumbler out. The next morning the battery was dead.

Could I have damaged something electrically by leaving the key on all night? (The truck has a 460 engine)

Any help is greatly appreciated, thanks.

 

Well I'm thinking that if leaving the key on too long was an obvious way to damage the electrical system someone would replied?

I have since charged the battery completely and the truck will still not start. It started fine before I did the repair so I'm thinking it is something I screwed up.

Would having the ignition switch installed too far forward cause the truck to kill? Any other ideas? I'm at a loss to know what to check next?

 

[QUOTE=4BigGreen;12700536]Hi,





Now the truck tries to start but won't stay running.


Does the engine quit just as soon as you release the key from the start position? If YES, the ignition switch may not be adjusted right.

 

Thanks 88n94,

yes the truck tries to start but won't stay running.

The engine stays running after the key is released for a bit. When we pour some gas in the carb we can rev the engine for maybe 5 sec then it sputters and dies.

 

Leaving the ignition in 'run' without the engine running can damage the ignition coil by overheating.

But you seem to have a fuel delivery problem.
Does your friend's 1987 F250 with a 460 have electric or mechanical fuel pump?

 

Thanks ArdWrknTrk, good to know.

I'm not sure about the fuel pump. I'll try to run over there tomorrow and take a look.

Now that you mention the fuel delivery system I did bump the extra fuel tank switch by accident when I was doing the repair. My friend noticed it and switched it back when it wouldn't start.

 

I checked for the fuel pump by tracing the line from the gas tanks. No sign of a machanical fuel pump.
I'm thinking on the rail next to the front gas tank sits an electrical fuel pump. Ill attach a photo when i get to my computer.

I disconnected the fuel line by the carb and no fuel sprayed out when I turned the key to the on position or when cranking.

Maybe i toasted the fuel pump when i left the key on overnight?

 

Pump should only run while cranking or the oil pressure switch is closed.
No power to pump with key on but not running.

You should ALWAYS have pump power while cranking.

 

That is the filter on the frame rail.

"Hot Fuel Handling" trucks have a low pressure pump in each tank.

 

Thanks ArdWrknTrk,

Good to know the fuel pump wasn't powered on all night.

Ok, here is what I thought was the fuel pump.



Could the fuel pump be in one of the gas tanks?

 

That is a switching valve. it also switches which sender the fuel gauge sees.

Yes the pumps are in the tanks

 

Thanks ArdWrknTrk,

So this truck has a fuel pump in each tank. That kind of leads me think maybe it's not the fuel pump causing the fuel supply problem. What are the chances of both fuel pumps going bad just because I replaced the Ignition Actuator arm and lock key tumbler?

I'm not sure what to do next. I checked the fuses for the gas tank switch and the electric fuel pump (from memory I think they were fuse 15 and 18) Both were good.

Any other ideas where to look or what to try before I drop the tanks?

And thanks again

 

I would look at the selector relay, since you should have power while cranking even if the oil pressure relay was bad.

These two relays should be side by side and up near the drivers side hood hinge. ... But I have a mechanical fuel pump so can't say for sure.
They may be over by the starter solenoid.
It is my understanding the 1987 'Hot Fuel Handling' system is unique to that year.

Hopefully someone with the EVTM for this year can confirm this or post the schematic.

 

Thanks again!
I wish my friends truck was in my driveway and not 1/2 hour away. I'll get over there this week and check those relays. That may be the problem. I did notice that the gas gauge only works on one of the tank selections and both tanks have fuel.

 

Have a look at the diagrams that Subford has posted in this thread.

https://www.ford-trucks.com/forums/1...t-fueling.html

Maybe even print it and take it with you, if it's so far away.