weird idle problem after shop visit

[captd108]

i went to strauss to get a water pump and timing belt done since i work there and everything and get a discount on the work. Anyways as soon as i started the engine the idle sounds really rough and i know before i brought it there everything was running perfect and smooth and had just gotten it dynotuned. They also needed a new belt tensioner since my old one was said to have been going on its way out. Now my idle is rough and it bounces on the tachometer like up and down in very small increments. They didnt know what it was though and that they drove it thinking timing was off but everything else ran fine. Could it still be that timing is off and making the engine rough at idle but not during driving or atleast not noticeable. They said that since the battery was disconnected for 12 hours i could of lost all my memory on my ecu and all my settings on my safc? even though my settings still look the same as they were? What else should i look for b/c this happened right after the install and it was running perfect before. thanks

 

[ADrewzki]

Often after you unplug your battery and your ECU resets, you have to run the car around a little bit so your car can "learn" fuel curves again. I would highly recommend getting it timed again just to be extra careful. If it still persists after a week, I'd start to worry.

 

[oldman]

Don't take a chance on something like this, check the timing marks immediately before you even drive the car again.

i went to strauss to get a water pump and timing belt done

 

[captd108]

well they checked it with a computer and said it was correct, and then i brought it to mitsu dealership and they said its correct. Right now my car is at the dealer waiting for a hose to come in that tore open, but after that if the problem still persists i am gonna bring it back to turbotrix and the guy that tuned my car is gonna check everything all over for me to see what the problem could be. He thinks it could be timing and even if the computers and guns say its right it could still be off. Also i drove it for 2 days and the computer never relearned anything it looks like.

 

[snoddy]

I had the same thing happen to me today (on a 1G though). I had the car in for a front main seal replacement (which involves the replacement of the timing belt etc.) and when i drove it this evening, it had a rough idle that sort of "missed" every once and a while, but while driving it performed like there was nothing wrong. I am going to take it back tomorrow and have them double check the timing and balance shaft.

Let me know what happens with your car if you find something to fix the problem.

 

[captd108]

well its good to know sum1 else knows exactly what im tlaking about. Anywyas im gonna ask mitsu to take a better look at it visually besides just using the gun and computer. If nothing changes im gonna bring it to turbotrix on tuesday to have them look at it for me. They said its most likely timing and somehting that computers and guns may not catch all the time. Snoddy if you find out what the reason was let me know please. Thanks

 

[snoddy]

more...yesterday, the idle problem became significantly worse. Now instead of missing occasionally, the idle bounces all over the place...from almost dying to 1200 rpm (seams like the ECU is constantly correcting for something). I replaced the fuel filter, all of the vacuum lines (except for a few I couldn't reach, but I inspected these and they looked fine), BISS screw is adjusted w/ new o-ring, plugs and wires are fine, no fouled plugs, compression tested (155,155,141,145), and new air filter. Vacuum on the intake bounces between 17 and 10 in Hg as the idle fluctuates. I have NOT done a boost leak test or cleaned the throttle body, but when I am on the gas, the car makes 10-12 psi (stock gauge) and pulls just fine. I visually inspected the throttle body and it looks really clean. I don't suspect the O2 sensor because the idle problem happens when the car is both cold and warm. Also...no codes (no check engine light). I don't suspect any problems with fuel delivery because the car doesn't run any differently at WOT. I do have a small exhaust leak possibly in the flex pipe, could this cause the idle problems? My wife did say that the garage had a strong fuel smell, and my exhaust smells a little like the engine is running rich, but i still am having trouble diagnosing the problem.

Anyway, the car is at the shop today to have the timing reset (I don't have a timing gun) and they are going to try to figure out the problem too. I will keep you posted...Eric

 

[captd108]

hey in case any of you were wondering i had mitsu check the timing belt and they told me that it was a tooth off about and they fixed it and they said my car runs like its supposed to now. My concern is if i drove it for a couple of days with the timing off by a tooth could that have caused any damage internally. I only drove it for about 3 days. Thanks

 

[maddwrenches]

its should not of hurt anything if it was more off tho it would of bent a valve so adleast your ok now

 

[oldman]

hey in case any of you were wondering i had mitsu check the timing belt and they told me that it was a tooth off about and they fixed it and they said my car runs like its supposed to now. My concern is if i drove it for a couple of days with the timing off by a tooth could that have caused any damage internally. I only drove it for about 3 days. Thanks

Do a compression test when you get the car back to be sure.

 

[snoddy]

shop installed belt off by 2 teeth, but the idle surge masked the real problem. Took it back, they fixed it and the car runs great (and I have eliminated all of the potential idle surge crap for the future)

.eric