Hi Guys,
Working on
92 F150
6 Cyl 4.9L MFI
2 WD

Does not want to start and asking for advice.

The story on this truck is I had it parked for several years and I brought it out of retirement.

Did not have to do anything mechanical to the engine. Over a 2-week period I made several trips around town and no issues. Took a road trip of 125 miles and no issues. There were several times I turned the truck off.

The next time I drove the truck, it was bucking like a wild bronco. Drove it a bit and after getting up to speed I kept the peddle to the floor to keep it going.

After that adventure, I thought maybe the fuel filter is the issue, so it was replaced. That did not resolve the issue, and now it won’t start at all. Turned the key from off to on 10 times to get the fuel pump to prime and it sputters just a bit.

That makes it sound like a fuel volume issue, so I thought I would look in the tank and pump. Opened the tank and it was clean on the inside. I replaced the tank and pump about 10 years. Pulled the pump and the filter was clean. Put it back together, same thing.

What could it be?

Thanks

 

Several years of sitting can require a few major test.

Have you checked your timing
Have you checked your fuel pressure
Have you checked for spark
have you checked for any codes?

 

My money is on it needing a new fuel pump..Old electric in-tank mounted fuelpumps dont like to sit around then be asked to perform perfectly again...Almost every vehicle Ive bought over the years that has sat more than 2-3 years with mileage above 150k I had to do a fuelpump on and most of the pump replacements Ive done were usually with-in a week of bringing it back from the dead.Some the pumps never activated again[locked-up] and had to be changed asap....

Reason why is nobody takes the time to drain the fuel from the tank and put fresh fuel in plus change the oil and filter before starting the vehicle back up after its slumber because as the vehicle sits water builds up inside the tank through condensation also due to the fact that the ethanol in the fuel attracts water........The pump sits in a shroud of water that accumulates over time then it gets sucked in making alot of components wacky like anti-backflow units on the gastanks , the fuel injectors , fuel filter and the fuel regulator aswell as the pump itself ...

When you opened the tank to inspect the pump you should of tried to power the pump and check fuel tank output pressure with a gauge before reinstalling tank...Without a regulator the fuel pressure will read way above 40psi closer to 60psi..

Autoparts stores like AutoZone rents fuel pressure testers free of charge you have to leave the price of the tool as a youll bring it back jesture and you get every penny back when you return the tool with all components..

Spray some starter fluid into the airbox...If truck runs get a fuelpump...

Good Luck

 

Fuel pump was OK. Determined that the MAP sensor was bad. Based that on the "bucking like a wild bronco" and needing tokeep the pedal to the floor after getting up to speed.

 

Seeings this thread is headlined "Wont Start" getting it started by changing the MAP sensor I dont think would be the culprit in that area as my truck runs without it plugged in....It runs really rough and throws a CEL but it starts and runs....

..