I just did a rear valve cover and upper oil pan seals. After putting everything back on and all tightened up when i started the car the idle sucks. its not bad until the idle settles down into the 6-700 rpm range. And when it drops to 500 it basically shakes back and forth between 5 and 600 or 6 and 700 and you can see the motor shaking as well. Its real rough. I thought maybe a vac leak but cant find it.. then maybe thought a coil pack was bad? but im really not sure. Yall got any ideas?

Thanks,
Matt

 

I had those symptoms after failing to reconnect a vacuum hose from the MAP/BARO solenoid to the bottom of the throttle body. It threw a code, though, so I knew where to look. Also the hissing sound it made was pretty obvious with the hood up.

If you cleaned out a plugged EGR guide tube, you might need to go through the idle speed tuning procedure.

Maybe the throttle position sensor and/or closed throttle position switch could also cause those symptoms. You would've disconnected them to remove the UIM, so maybe the connectors aren't back on there tight?

 

thanks, I did not clean egr tube. I did not mention it was a 99 model that I was working on. Not sure if that makes a difference. Now my service engine soon light is on..not real sure y but im going to get it scanned tomorrow to find out. Ill re check the connectors. Im hoping there is a hose not connected somewhere..but i havent found it yet. Thanks for the input!

 

Did u evr find out wat it was? Im having similar issues.

 

Thread from the dead.

Idle Issues? Check all Hoses, Clean your MAF, IACV, TB, and EGR.

Also. please full and complete sentences; some of the guys on here are very particular about spelling and abbreviating the hell out of things.

/thread

 

Lies.

 

Fixed.......

:Hide:

 

Anyone got a link to a discussion around diagnosing a misfiring cylinder? Oddly enough, every once and a while I'll start up my 2000 SE and it will be clearly missing. If I put it under power (break and in gear) you'll rattle like mad. I replaced my spark plugs and it happened again a few days later.

To make it even more strange is that if I stop, turn the car off and back on, sometimes the restart will get it running again. Almost like it needs a reset.

I replaced my Mass Flow Sensor a year ago, so that's not it. I thought it might be a coil missing but I do NOT want to drop $300 bucks to find that only one is bad.....

Anyway, to my original question, is there a thread on diagnosing your coils? I figure I should start there.

 

There are many threads that explain the easiest way to diagnose which coil is bad. something along the lines of warm up the engine and disconnect each coil 1 by 1. if there is a hiccup when coil is disconnected then that is a good coil. if there is no response from the engine then that coil should be replaced.

Im sure one of the old timers will correct me if Im wrong or at least link to the corresponding threads.

GL

 

Wow my thread from 2009. Yes I did get it fixed. It was probably something unplugged, either the maf or a vac line.