FInally Solved Idle/Stumble problem... but now what???

[SHO Off]

Just to let everyone know what was wrong...

"Well, Plugs and wires were new about 5-6K Km ago... Plugs were gapped a lil
larger than spec at around .055 instead of .042 i believe. Symptoms didnt
start to occur until stage 2 kit went on... I had stumble problem from oil
in the plug wells, but that was cleared up with new top end gasket set,
plugs, wires, etc. I didn't try a new IAB valve, which is probably alot of
my problem. I had no problems with it, until I took it off to clean it, when
i was doing the Stage 2 kit. Symptoms are rather odd and tough to describe.
Upon startup, when cold(ie winter) or hot(ie summertime), the car needs to
be idled for about 5-10 mins before it will run properly. This is only on
startups that have a long peroid of time between them. Ie starting in
morning after sitting all night. The car will run very rough, and the idle
will drop down very low sometimes, causing it to stall out. If you do not
let it idle for 5-10 mins, and you try to drive the car just after you start
it up, the following happens. Once your in gear and let out the clutch, you
give it a lil gas to get going, although the rpms dip low, about 300-600 and
the car bucks, and wont accellerate or rev up the rpm's any higher no matter
how much pressure you put on the gas pedal. if you really step on the gas
during this time, it trys hard to get the rpms up and go, but sometimes you
hear a slight popping noise and i just stop cuz i dont wanna break
anything... Also my idle with the chip and stage 2 kit, seems to still be at
stock levels. Although my idle when engine is warm will go from 800-1000 or
so. Sometimes the car will run rougher and the idle will drop below 800
sometimes causing the car to stall out at a stoplight. I was always
wondering about the IAB valve, TPS sensor, MAF being programmed right, and
LPM being done right. Havent tried stock 55mm Maf yet, I have to take all
the new stuff out, which is too much of a hassle right now. Although I can
tell you that when I unplug the 80mm Maf and still have the chip in, the car
throws a CE light, but runs much smoother and better, although I get really
****** gas mileage... "

Now since then, I have changed out my TPS, IAC, and reset the ECU and LPM many times, with no avail.

I have taken out the 80mm MAF and LPM last nite, tested last nite and this morning on the cold startup, and guess what... PERFECT... Runs great, can startup and drive right away, no problems at all.

Now Ive been told to try a reburn? Will this help? Or IS it a bad MAF?

 

[luigisho]

Did you regap those plugs to spec.? I'm betting the maf is the problem. When you unplug it it goes to default mode and runs better. Therefore the sensor is not reading properly. You can always try to clean the electrodes hanging down in the maf body with some electrode? cleaner from Radio Shack. If that doesn't work you may need a new sensor.

<small>[ April 27, 2002, 12:31 PM: Message edited by: luigisho ]</small>

 

[CTOESHO]

Hey SHO OFF,
My SHO has been recently been doing the exact same thing. It runs fine after that inital morning startup. The rest of the day it's fine. I don't "see" any oil in my plug wells, but I was told it could be the IAB valve. How do I go about changing that? Thanks.

 

[SHO Off]

Well I talked with Josh at SHOnut, I bought everything through them from SHOshop. The MAF was brand new, so im leary about thinking its bad. But the LPM is needing a reburn I was told. I did not gap the plugs back to spec, I am changing out plugs again in a few months, due to my Zex kit going in.

Also To change out the IAC, (IAB), you will see it sitting just beside the TB, on top of the fuel rails. Now check out this link and print out the sheet, easy as pie, took me about 10-15 mins to do. Watch the Lower screw so it doesnt fall down below into the fuel rail area.

http://www.shotimes.com/SHO3iabclean.html

disregard the cleaning part, just use same instructions for removing and installing new sensor.

Also remember to let the ECU relearn itself after the new sensor goes in.

Good luck.