arrowcamaro

opti (and harness),O2's,PCV,wires, plugs, egr (and solinoid), checked vacuum(21*), cleaned tinys,throttle body, and IAC. TPS is within spec. car still has irradic idle when in gear (stopped). it also likes to unlock the converter on the highway every so often for no apparent reason.

tonight i had the A/C on and the car idled perfectly while waiting at lights, any ideas? lazy IAT? maybe just bumping the idle up a hair would help? i have autotap but im not too familiar with it, anything in particular i should look for?

this is starting to **** me off

mods-2800 edge, gears, bryan herter programming, other than the idle condition it runs like a raped ape, but i want it to idle like it should

EDIT- also changed the coil,and the IC module

Injuneer

Describe "erratic"...... does it shake with minor irregularities/misfires, or is the idle rpm surging and varying more than the normal +/- 25rpm? Or maybe a combination of both?

If you have an AutoTap data log, I'll be glad to take a look at it for you. You just need to send it in .csv format so I can open it with Excel. If you are looking at the data log, look for irregularities in the MAP sensor readings at idle.

Do you still have the original coil and IC Module in the car? How many miles on it? Ever cleaned or changed the injectors?

Just curious.... what is the "tinys" that you cleaned?

arrowcamaro

the "irradic idle", surging RPM +/- 3-400 RPM like say stopped at a light, it will surge getting progressivly worse till the IAC kicks in brings up the RPM and smoothes out till the RPM dropps back down and starts the cycle again. it has the original coil, IC module, and injectors (never professionally cleaned). the "tinys" are the little metal metering wires inside the maf (cleaned with a q-tip and rubbing alcohol)

i also replaced the intake gaskets along with the other things mentioned without any change in the condition...

any idea why it idles perfect with the A/C on, and not with it off? i will work on getting you a log, i have some stuff to do today, and i need to figure out how to get it to .csv format...i appreciate your help

Dave89IROC

A/C puts a load on the engine and forces the PCM to up the Idle/IAC position

arrowcamaro

understood, but why doesnt the IAC keep the idle happy when the A/C is off? could the IAC be lazy? or doesnt it control the idle with out load ie.power steering, A/C, defrost? help me learn

arrowcamaro

forgot to mention, 61k on the car

blackz97

Checked for leaks in the intake?

Steve

arrowcamaro

it held vacuum, so id say the intake is good

BigJustinZ28

my car does the same thing ,but not all the time , it seems like using the a/c triggers it more often but it does happen when its off too. About twice a week this happens , then its gone.

96capricemgr

Was the BH tune before or after the Edge? If it was before, an update to the tuning is in order. The lighter looser converter can confuse the pcm and it will suge looking for some load on the engine. My cammed Caprice with programming even did this till I had Bryan send me an update for the TC, I had thought the cam and bumped idle for it would have taken care of the problem that was the only reason I had not had Bryan send me a new tune before I drove it.

BLinindoll

I am about 95% sure I have the answer for you guys. I had the same problem. Took me 3 weeks to figure it out. BTW, it's FREE!!! Check this out...


Click here

arrowcamaro

even after the tune, it wasnt rock solid, but it was barely noticeable....now it surges to the point that it gets to about the 12-1300RPM range. when im stopped at a light, i have taken to throwing it into neutral, it's more steady(the idle) than sitting there in drive.

i replaced the IC module, no change

BLinindoll

Yep, exactly what I had to do. I'm tellin ya, try the mod. It worked for me.

Red-LT1

I had a similar problem. Turned out to be my coil.

arrowcamaro

well, i changed the coil and did the mod-no dice still surging gonna check the fuel pressure tomorrow, what kind of a reading is normal?

i also took out the airfoil, removed ECU and checked connections-all looked good. i need to get my autotap working... and get that log file to someone who knows what there looking at.