993 engined SC, hunting idle can chip help?

[Mike the mechanic]

Hey kids, I have read that it is quite normal for a 3.6 to have a hunting idle when using a lightweight flywheel, and a proper performance chip can cure the problem. Is this true and what chip is recommended?

The car exhibits hunting idle when fully warmed up. Checked for vacuum leaks or other possible problems and everything checks o.k.

thanks!

[marcesq]

I have read the same thing, and think that centex is one of the chips used by conversioners.

There are plenty on the board so maybe they will chime in.

[Rick Lee]

Which year 3.6 do you have? After '95 I'm not so sure it's an easily chippable fix. Drop Steve Timmins a line at
www.instant-g.com. He does this stuff for breakfast and stocks everything you could ever need.

[Mike the mechanic]

I forgot to mention this is a 1995 3.6, pre OBD-II.
Thanks!

[Desert Man]

Go to http://www.rennsportsystems.com and I think you will find a lot of the info you are looking for. The 993's used the dual-mass flywheel to keep idle speed steady and to keep the revs from dropping to low and stalling when coming to a stop. The DM flywheel and the DME worked together to prevent this, but it is easier to chip a '95 than the '96. I just bought a '96 and I know that according to Steve Weiner at Rennsport if I ever switch to the LW flywheel I will have to buy a DME from a '97 because the '96 is not chippable. The '95 is the easiest to chip and according to the 993 board on Rennlist, Steve Weiner makes one of the most effective chips around. You might want to call him if you have other questions.

[Bill Verburg]

Since the ? was about a 993 engined SC, the dual mass fly wheel has long since departed the scene. From my experience the idle should be rock steady even w/ a stock chip. Hunting at idle could be from one or a combination of issues Such as

• Dirty Idle stabilizer
• Vacuum leak(ok I know this was checked)
• O₂ sensor ist kaput

The chip can cure the issue related to dying on trailing throttle when coming to a stop.

The '95 has a nice easily replaced 55 pin chip

[pbs911]

What Bill said. The chip used in the conversions are not used to prevent the idle from hunting. I would double check for vacuum leaks and put a gas analyzer on it. I would bet on the fuel mixture being too rich.

[Desert Man]

Bill, the reference was to a LIGHTWEIGHT flywheel. I believe the sympton Mike suggested do relate to the issue with the DME interaction. I am not the expert on 3.6 installations you are, but I do know the 95-98 3.6's do have this problem and it is related to the chip in the DME. Take it for what it's worth.

[Joe Bob]

I have a cyntex chip clone available, BTW....most likely a vacuum leak.

[Mike the mechanic]

Guys, thanks for all the replies. Your opinions/advice is higly regarded. Mikez, how much for the chip?
Paul, come to think of it, the car DOES seem to run a tad on the rich side. I know there are no adjustments to be made, all the tune-up related parts are new, no vacuum leaks, injectors have been cleaned, so this leads me to belive that the MAF may be going bad. He still wants to upgrade the chip for more power, so we'll see what happens after the we replace it.
What's a good way to check the MAF?

Thanks guys!

[slakjaw]

hmmm if it was OBD II there is an idle relearn prosses

but for 95 i am not sure

i did this on a GM once

disconnect battery to clear the memory
reconnect let car idle for 15 mins shut off
start again and let it idle for 15 more mins
all with out touching the gas pedal

i have no idea if this will help this car or not
but its free maybe worth a try


LATE
K
71` 911

[Desert Man]

The manual for my '96 state that after a battery is disconnected, start the car and let it idle for 10 minutes. When the battery is disconnected, the DME loses all codes stored and has to remap everything on startup and it takes 10 minutes to do so. It also says the idle may be too high or may shift up and down during that time.