need help rough idle no power!!

[tlr]

OK. I just got the Montero back together. 1999 Montero. I did the valve stem seals, fixed some exhaust leaks and replaced lifters. It was running fine before this. Now it doesn't wanna idle has no power on the low end. I wouldsay off idle to half throttle just doesn't wanna move good. Past half and full throttle pulls really good. Does anyone have any suggestions??
Thanks.

 

[mapper]

Did you get your throttle cable/cruise control cables installed properly?

Double check all vacuum lines. I seem to recall reading (waaaay back) that someone once missed re-installing the little vacuum hose on the left side of upper intake plenum (slightly underneath) and had similar idle issues. Anyway, double check (physically and mentally) all connections. Sometimes you visually miss re-connecting something that you recall disconnecting if you rethink the tear down process. If you don't lick it you may want to scan obd system to see what codes are setting.

 

[Jay Ayala]

Yes that is a good suggestion. Also check all off the electric connections.

 

[billygoats]

I had similar symptoms when I put my top end back together. Mine was attributed to vacum lines at and around the egr crossed.

 

[billygoats]

Hope this helps.

 

[tlr]

I'm getting po300 code random misfire.

 

[tlr]

Now I'm getting po170 po173 po304!!! If the crank angle sensor is faulty would this cause these codes?

 

[TheMole]

Although tedious, I think the best thing to do is to go over the reinstall process, especially if it was running fine before. I remember getting a p0400 egr flow code after I changed out my spark plugs and wires. It ended up being a tiny vacuum hose I forgot to reattach. Hopefully yours is something as simple.

 

[tlr]

Well I took the manifold back off and then reinstalled with no luck. Checked for vacuum leaks didn't find any. Doesn't make any sense.

 

[Jay Ayala]

It has to be an electrical harness clip issue. My buddy MK who also posts here on the forum found cracks in the wiring leading right up to the harness clips. Adjusting and moving the wiring would someone's make it better or worse. Take a look and inspect the wiring for cracks or at least make sure everything is properly connected.

I know it sounds stupid but just check.

 

[tlr]

OK I think I got it!! I think its the maf when I unplug it it runs great no stumble no hesitation it just goes. Idle is a little high but it runs great. When I plugged it back in it runs like crap. What do ya'll think??

 

[Clem]

When I plugged it back in it runs like crap. What do ya'll think??

Sounds like you found it!

HTH,

Clem

 

[Jay Ayala]

Sounds like you found it!

HTH,

Clem

+1

 

[billygoats]

Unplugging the maf puts the car into a default mode to compensate for a loose or missing maf signal. Just because the truck runs better with it disconnected, does not mean the sensor is bad. You need to do a test with a multimeter to test resistance of the maf to verify if it is in fact bad, or something else causing it. If it was fine before you did your timing belt, it's not likely it failed during the time you were doing your repairs.

 

[tlr]

Well its not the maf. I've been all over the engine for shorts and vacuum leaks and have found nothing. The only code I get is random mis fire makes no sense.