Three days ago my idle grew a surge. It usually sits at 1000k, So now it is surging back and forth between 1k and 1800k roughly. It is only at idle and sorta comes and goes but it is constantly there.Generally I have been able to get surges out in the past by backing out some fuel at idle. I haven't played with the idle set screw because I broke the top off mine and need to swap it out, I did however back some fuel out with my PMC and that didn't seem to affect the idle the way I needed it to. I have quicky glanced to make sure my caps and hoses are all where they should be. So aside from an idle screw asdjustment what could be the culprit. Keep in mind that this started out of the blue, no work was done that could prompt something like this. I'm reading if anyone has any input.
TIA
Dave

 

vac leak? time to start digging

 

fd3boost,
i'm in the middle of diagnosing the same problem. if i come up w/anything i'll pm you. please do the same if you find the problem.
andy

 

could it be the idle speed control solenoid is no longer working?

 

I'll look into that. My checked for vacum leaks and i couldn't find any. I am full non sequential and my engine bay is pretty baron, no abs, cruise, etc. So it doesn't take more than about 5 min to look everything over. I still couldn't find any leak so if i do have one its a small one. I'll check the ISC solonoid with a voltometer. Thanks

 

I had the same problem The TPS was way out of wack.
AG now.

 

hey dave, check the o2 sensor...."one time in band camp"...uh i mean one time my idle strarted going crazy. fiddled with the idle screw and checked everythning else and nothing. replaced the o2 sensor and everything was fine. the o2 sensor was old and the wire was about to snap. kvn

 

Thanks for all the suggestions guys, I will keep at it and let you know how it goes.

Kevin, don't **** but I don't use the o2 sensor.

 

O2 sensor? Where might that be? Only one I know of is the widband in my tuning drawer...

 

LOL, You too huh Justin?

 

Probably the TPS. Vac leaks are normally constant and don't surge. I had the same problem. Try to adjust it, but if not you can get one at the dealers for like $190.00. Good Luck.

James

 

I belive that I have fixed the surge. I had a cap ona nipple that seemed slightly loose. I replaced and zip tied it down again. Idle seems to be smooth again.