Don't like the adverts?  Click here to remove them

LJ70 No Power

JonFJ1969

Member
Joined
Feb 6, 2013
Messages
167
Hi All, just bought a 1990 LJ70 that had been stood for a while, seemed to of had been running on the dregs of what was left in the bottom of the tank, took it out for a spin and seemed to loose power and wouldn't rev, eventually got back and the fuel filter was clogged so i changed it, put about half a tank of fresh diesel in her and all seemed fine but she still seems to have no power. i did the priming of of the fuel filter after the change and she runs fine but after a while it has no power and doesn't want to idle, tried to bleed the filter again and noticed when running the priming head seems to be drawn back into the body, eventually it comes back so i am thinking it has an air lock somewhere, can some one point in right direction of what to bleed next? and how. as you can tell i am not used to working on a diesel. any help very much appreciated, cheers Jon
 
I haven't done it but replacing fuel pipes for new at the tank on this age of truck is mentioned quite often on the forum .
 
Hi there. This happened to my 1st lj70 back in 2007. If you have the original diesel filter primer head. The diaphragm goes in the primer and the engine draws air in. I struggled to find it out, changed the fuel lines etc and it was that.

Luckily you can use a diesel filter assembly off any motor.

Hope this sorts it out for you. ..iwan
 
Hey Guys, thanks for replies, i guess i now have a job for the xmas break, i will drop the tank and replace / clean out the filter assembly inside whilst blowing out the fuel lines, the fuel lines kinda look new but so i am sure it is s h one t in the tank creating this vacuum / issue. will let you know how it all goes, cheers jon
 
Hi All, just an update, changed the internal fuel filter assembly, cleaned out all gunk from 20 years plus of buildup and she is back and running with full power. the old fuel filter was so clogged it was actually deformed by the vacuum created from the pump. thanks for all input cheers Jon
 
Don't like the adverts?  Click here to remove them
Great you got it fixed Jon. I'm sure this thread will help other people in the future experiencing similar problems. :thumbup:
 
Hi All, just bought a 1990 LJ70 that had been stood for a while, seemed to of had been running on the dregs of what was left in the bottom of the tank, took it out for a spin and seemed to loose power and wouldn't rev, eventually got back and the fuel filter was clogged so i changed it, put about half a tank of fresh diesel in her and all seemed fine but she still seems to have no power. i did the priming of of the fuel filter after the change and she runs fine but after a while it has no power and doesn't want to idle, tried to bleed the filter again and noticed when running the priming head seems to be drawn back into the body, eventually it comes back so i am thinking it has an air lock somewhere, can some one point in right direction of what to bleed next? and how. as you can tell i am not used to working on a diesel. any help very much appreciated, cheers Jon

I have had similar problems too. Black snot blocks the plastic mesh on the end of the pickup pipe but the pickup pipes which leave the tank are also prone to rotting. The fuel filter head is a give away if it never primes rock hard.
 
Back
Top