97 993 LW RS clutch/flywheel modification

[stevemc993]

A few months back I installed a new RS clutch and flywheel. The good news is that the car revs quicker and is more fun to drive, especially for DE days. Bad news is that the lighter weight causes the car to stall frequently. Have cleaned the idle speed control valve and it did help, but car still stalls!

So, I think my next remedy is to flash the ECU. This is an OBDII car so can't just chip it. Steve Wong has a good reputation with OBDI chips, but doesn't do OBDII... Have considered Rennsport (Oregon) or FVD in Germany, but this is not cheap!

Does anyone out there have suggestions other than learn to heel/toe better? Very frustrating.
Thanks

[matt demaria]

I had a 96 with a similar issue. I tried rotating the ICS valve to create a slower decel, but I finally scanned it and found a 1602 code. This was an alternator code (in this case). When this code occurs the ram in the ecu is cut off so the memory of the idle speed is lost. It is a two trip code so if the alternator does not spike in the next 2 cycles the code is gone and the memory of the idle is restored.

[johnsjmc]

Originally Posted by matt demaria

I had a 96 with a similar issue. I tried rotating the ICS valve to create a slower decel, but I finally scanned it and found a 1602 code. This was an alternator code (in this case). When this code occurs the ram in the ecu is cut off so the memory of the idle speed is lost. It is a two trip code so if the alternator does not spike in the next 2 cycles the code is gone and the memory of the idle is restored.

An alternator code if I recall can be caused by the use of aftermarket fan belts in a 993. There is a TSB about it somewhere.
I have read on rennlist that a new valve will sometimes work to fix the stall even when the old one is squeaky clean.
My 95 with LWF stalls only very rarely when cold.
I thought the variorams were mostly immune.

[jhg41977]

I have a 96, no issues. I havent heard of a 96-98 having stalling issues.

[gc96]

Originally Posted by jhg41977

I have a 96, no issues. I havent heard of a 96-98 having stalling issues.

I also have heard that the idle issue was only for the '95 models and that the '96-98 models are capable of adapting to deal with the LWF with the stock programming. You might consider resetting the ECU by disconnecting the battery and having it re-learn the idle adaptation settings with your LWF. Do a search on the Rennlist.com 993 forum for posts by Steve Wiener for the correct sequence to follow after reconnecting your battery to get the ECU to quickly adapt to the new flywheel.

GC

[johnsjmc]

Rereading your post ,occasional maybe but FREQUENT stalling is not usual for a 96 up . I would fully look it over for small vacuum leaks while running at idle. Wiggle fittings etc. There are lots of small vac hose possibilities for leaks.

You can also use a spray can of brake cleaner or an UNLIT propane torch to find leaks while its idleing.

[stevemc993]

All - I too thought the 97 cars would be immune to the problem, but...

I checked for air leaks and am about to replace the ICS valve (have cleaned the old a couple of times).

Will try the Steve Wiener battery disconnect procedure as well.

Thanks for the help!

Steve