**please help** trouble with idle and voltage
CF Veteran
Joined: Jun 2011
Posts: 2,858
Likes: 1
From: Nor-Cal
Year: 1990
Model: Cherokee
Engine: The venerable 4.0
Your rings are likely worn. Try restore as a last ditch effort. I've had very good luck with it in the past. Compression numbers were up on my old v8 about 20 PSI.
Thread Starter
Seasoned Member
Joined: Oct 2011
Posts: 348
Likes: 0
From: Chicago
Year: 1989
Model: Cherokee
Engine: 4.0
Originally Posted by Slick761
Your rings are likely worn. Try restore as a last ditch effort. I've had very good luck with it in the past. Compression numbers were up on my old v8 about 20 PSI.
Last edited by T85konrad; Dec 12, 2011 at 10:47 AM.
CF Veteran
Joined: Jun 2011
Posts: 2,858
Likes: 1
From: Nor-Cal
Year: 1990
Model: Cherokee
Engine: The venerable 4.0
It's called restore its in a metal can. Three sizes get the v8. http://www.restoreusa.com/
Last edited by Slick761; Dec 12, 2011 at 11:43 AM.
CF Veteran
Joined: Jun 2011
Posts: 2,858
Likes: 1
From: Nor-Cal
Year: 1990
Model: Cherokee
Engine: The venerable 4.0
You could try it... That stuff doesn't do that much unless you take your injectors out and soak em in it... Might help a little with the mileage. There is a chance your injectors are bad. Basically to diagnose this you need a compression check and possibly a leak down test.
Seasoned Member
Joined: Aug 2009
Posts: 460
Likes: 2
From: Long Island NY
Year: 1989
Model: Cherokee
Engine: 4.0
My 89 xj used to destroy the air filter too it turned out to be the PCV tube going to the back of the valve cover was all gunked up and clogged. i converted it over to a PCV valve and replaced that skinny tubing to a 3/8" fuel line. now the crankcase properly ventlates i have no more oil going on to my air filter element
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Cars where made....long ago...with a "road draft tube". Metal tube going straight down, bottom cut at a 45* angle, so it would suck some at speed, to vent that stuff instead of fouling your air cleaner.
Thread Starter
Seasoned Member
Joined: Oct 2011
Posts: 348
Likes: 0
From: Chicago
Year: 1989
Model: Cherokee
Engine: 4.0
Originally Posted by DFlintstone
Cars where made....long ago...with a "road draft tube". Metal tube going straight down, bottom cut at a 45* angle, so it would suck some at speed, to vent that stuff instead of fouling your air cleaner.
Thread Starter
Seasoned Member
Joined: Oct 2011
Posts: 348
Likes: 0
From: Chicago
Year: 1989
Model: Cherokee
Engine: 4.0
Originally Posted by Slick761
Hahaha its true though. Jeez don that was in what the 40s?


