Hello all --

I've just finished installing a new timing belt for my 88 Trooper. The old one was so oil-soaked and cracked I am surprised it had not broken yet.

During the install, I noticed the old belt was mis-aligned by one tooth - when the cam was aligned correctly, the crank sprocket was one tooth counterclockwise from where it should have been. I am not sure whether it had slipped or whether the previous owner had installed it incorrectly (back in 2002 or so).

I replaced the cam & crank oil seals, installed the new belt correctly and put it all back together. Now, I finally have a correct 750 RPM idle (used to be 1000-1100, could not get it to idle correctly) but the truck is sluggish until about 3000 RPM or so at least. Not terrible, just not as peppy as it used to be.

My current theory is that the timing at the distributor may have been set while the belt was off a tooth by the old owner. Could this cause these symptoms?

Also, the crank pulley timing mark is not aligned with the keyway - maybe the balancer is failing and the outer ring is spinning a bit around the rubber core? Makes it hard to check the timing...

Anyone seen these issues before?

Thanks in advance...


1988 Isuzu Trooper LS
2.8l Isuzu 4JB1-TC intercooled turbo diesel
www.dieseltrooper.blogspot.com