Alright.. i need some help and opinions.. i have just replaced the timing chain, oil pump, hoses and took out the cork gasket around the oil pan.. Everyone has recommended that's not needed and just use black RTV.. I did this because I had a few oil leaks.. In addition, i noticed a drip of oil coming from the bottom of my alternator.. Figuring something is leaking from above.. i now have no leaks but my idle is rough when i place the transfer case in Hi.. When I place the transfer case in Low the idle is perfect.. I'm confused, are the belts too tight? Maybe the distributor is a little off, since I had to remove it when taking the timing cover off.. But why would the timing be fine in Lo but in High.. The rough idol is consistant up and down in Hi.. Any thoughts?

 

A long shot, but might be worth checking/bypassing the vacuum switching valve controlling the fuel pressure regulator:
http://www.4crawler.com/4x4/CheapTri...ine_Pix/8.html

It is tied into the 4WD switch via the ECU, might be acting up.

 

Here is some more info.. Last night i started it up in Hi and it idles fine (versus the other night when I started it up in Lo).. But when i place it in reverse to leave the garage it had an inconsistant idle.. The idol is great sitting still and when you start up.. Its when you start to drive.. Has anyone had this issue? The exhaust smells clean without a lot of fuel smell and no black smoke.. So the timing is fine.. I have replaced the PCV and other assorted tubing since it looked pretty old..

 

4Crawler forgot to include, Thx for always replying to us .. I will follow up on the lead you had about the vacuum switching valve in addition..