1. Home
  2. Jeep and Willys (new and old)
  3. Multiple fuel pump failures
  4. Page 2

Multiple fuel pump failures

Retired,

Can I ask about the mode of failure? You surely have a pile of these sitting around at this point.....and can stuff one in a vise to operate the lever and monitor whether or not it pulls/pushes or if you have a diaphragm/check valve failure. I know this doesn't duplicate the exact stroke of the pump lobe, but what do you have to lose if it indeed fails on the bench and you cut it open to investigate? I think you've gone beyond the one or two "bad" pumps off the shelf.

Just in case -- the hoses also fail (soften) internally, so that under suction it closes itself off to flow. With a low level in the tank, you'll get nothing.....worth checking if your flexible lines at the tank feel soft, but you're a bit early at 1989...

Jon

Reply to
Jon
Loading thread data ...

Good point, the alcohol in modern 'gas' dissolves the older fuel lines. The owners manual for the CJ7 258 plainly states do not use 'any' unless you are out of gas and need 'just' enough to get to real gas.

The pump should bench test.

He has an 89? Jeep has pumps for those, just not for the CJ's.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08
Reply to
Mike Romain

Is the return to the tank full of crud ? If so, you can get the symptoms you describe ; fuel pump pumps more fuel than the engine needs, pressure builds up in the fuel rail, eventually the pump can't pump any more. Vehicle stalls and wont restart. Over night pressure bleeds off, vehicle runs for another

15 mins. Eventually, fuel pump dies.

Had this in a Rover SD1 - took me ages and several fuel pumps to diagnose it.

Dave.

Reply to
Dave Milne

Dave this is a carbureted vehicle with a mechanical cam driven fuel pump. Still, some vehicles of that vintage have a return line and that could be the problem.

Cheers,

Earle

Reply to
Earle Horton

Dave this is a carbureted vehicle with a mechanical cam driven fuel pump. Still, some vehicles of that vintage have a return line and that could indeed be the problem.

Cheers,

Earle

Reply to
Earle Horton

That would be me not paying proper attention ! Still think the principle is sound enough to warrant investigation if stumped / more cash outlay is required.

Cheers, Dave

Reply to
Dave Milne

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.