Very Rough Idle.

[prophecy7115]

I have searched and there are many threads but none of them come to an answer in my situation.

My neighbor was doing my timing belt (He is a tech for mitsu), and in between i did a quick wash of the motor, I really didn't cover anything because it was very fast. Now after we got it done and started up the car, the motor seems to idle very rough, but drives great. I do recall my idle vacuum always in a steady 20Hg when viewing my boost gauge, now its at 10Hg. Iam guessing a boost leak. He just put the timing belt back on for me and I did the rest but when putting on the a/c tensioner I maybe then pulled something but i have been checking but nothing there. Just a little worried not shure if its a leak, could be the motor internally?

 

[DSM90AWD]

Funny, I had an old mitsu tech (not "old mitsu tech" from here ) do one of my original T-Belt installs and he'd forgot to check the rear BS alignment so was 180* out (likely the cause of the rough sounding idle) and did not properly tension the T-Belt after install allowing the exhaust cam to rotate one tooth off (likely the cause of the low vacume).

Check the above and make sure all the ignition components (coilpack, ignition module and plugs) are solidly connected and free of any moisture from your engine wash (WD-40 displaces moisture from terminals/plugs)

 

[oldman]

Funny, I had an old mitsu tech (not "old mitsu tech" from here ) do one of my original T-Belt installs and he'd forgot to check the rear BS alignment so was 180* out (likely the cause of the rough sounding idle) and did not properly tension the T-Belt after install allowing the exhaust cam to rotate one tooth off (likely the cause of the low vacume).

Sorry about that, I was younger then.

 

[prophecy7115]

Well this has to my first timing belt done out of all my cars. I just turned 18 , But what i find odd is that ever since this rough idle my car has actually been moving alot faster than before. I did tighten all of my exaust bolts (o2 housing, exaust manifold), And I did change the CPS and the crank position plate the sensor reads of, and the rough idle now just sounbds like I have some cam work done to my car. Iam going to do a boost leak test when i get home and find that leak. Thanks alot

 

[Evo_kid]

My brothers car has same problem, did you ever fix your problem.

 

[RacethisTSI]

my car sounded like it had a cam job done to it...it turned out to be my base timing was retarded, reset it to 10dgrees and it ideled perfectly, go less knock too.......it doesnt hurt to check...just a thought