I thought my opti was going out because when the car gets hot it was starting to miss under load. Now the idle is effected. Coming home today sitting at a red light the normal idle of 600 was pulsing up to 1100 and back down again. Also I noticed when I was on the freeway that the tach was jumping around. I couldn't really feel or here a miss, but it was moving up and down about 200 RPM's. Then while I was driving it just died. Started back up okay and made it home. I didn't think the opti would cause a surging idle. Maybe it's something else. Thanks if you can help.
Bill

 

ttt

 

anybody?

 

any codes?

 

There are no codes.
I was thinking about the opti. It would cause a miss, but can't see how it could cause a surge above idle. In fact I can't think of a single scenario in the ignition (coil included) that would cause a surge past my normal curbe idle. I guess I need to turn my attention maybe towards the IAC. I've heard that these can be cleaned. Anybody done this and how did you do it? If it was an O2 sensor, it should throw a code, right?
I have to believe that the low-mid RPM miss and idle surge are related.
Thanks for any insight!

 

If you have not done this lately, do it: CLEAN YOUR MAF!!! Use Qtips and rubbing alcohol or electrical parts cleaner on the resistors. Trust me if it does not fix your problem it will restore something else that you were missing.

 

Yes the O2 sensor should throw a code. I would take out the IAC and clean it to see if it cures the problem.

 

I believe guys who said cleaning the IAC has fixed their surgin problems... I have read posts where guys tell stories of heavily gummed IAC and/or even damaged plastic internals in the IAC.

I figure that if the IAC is sticky and the engine needs Idle control it may eventually overshot adjustment when it becomes free and as the engine over revs from calibration it will try to overcompensate ..... but being sticky it has trouble keeping up..

Check your IAC... clean it. Worst case scenario is that you rule it out from your list of possible problems.


Cant hurt to clean it.

my 2 cents

 

I assume your talking about the wires that go across the inside of the MAF. I'm going to claim ignorance on how to clean the IAC. Do I use the alcohol like I will on the MAF?

 

Its Gum and or Carbon what plugs the IAC for what I have heard... I would use some carburator cleaner on it...Alcohol sounds to mild .... I guess.



Marvin

 

You talking to me? Are you talkin to ME!!! (deNiro in Taxidriver)


Dude If you talking to me then ... no, I only talked about the IAC... ya know the one located on the Trottle.


About the MAF resistors... I cleaned up the tiny resistors and the metal bars that hold the resistors too... I thought they needed to sense quick air temp changes.

Marvin