smithk993

After putting a RS flywheel,new chip and cleaning the idle stabilizer on my 95 993, I am still having some trouble with stalling when coming to a stop. I've been told that adjusting the idle speed up a bit may also help.

Using the in-car tach, it shows a warm idle of 750-780rpm. I would like to bump the idle to around 900. I do have state inspections which check emmissions so I can't go much higher.

I understand that I can adjust the idle speed by turning the idle stabilizer valve in it's housing. Does anyone have some specifics on this process? Do I turn clockwise/counterclockwise when looking at the electrical connector end? Do I turn an 1/8", 1/4" or more? Any guidance would be appreciated!

Thanks.

Tom W

Keith: Who's chip did you use? How often does it stall? (and what causes the stall?)

I'm in the process of having the LWF installed in my '95 and plan to buy a new chip from Steve (Rennsport). One thing that has been stressed to me is to NOT let out the clutch at high RPM when coming to a stop but to let the engine do some of the braking and let out the clutch at low RPM.

smithk993

Tom,

I have a chip from Autothority that was supposed to correct the stalling issue. It helped a lot but is still not bullet-proof. Can defintely help with prevention by working throttle as a stop and waiting to downshift, etc. But there is still the time when something unexpected happens and you have to stop quickly, clutch in, revs drop and she stalls.

Have spoken with Rennsport. They are having some QA issues with their chip process and aren't shipping chips as we speak.

Keith

Edward

Tom,

I'd be curious of your results. I, too, have a 95 and when I need to replace the clutch (hopefully no time soon), I'd like to go the LWF/Rennsport Chip route. Feedback on drivability/stalling would be appreciated!

Edward

os993

I believe the ISV is set in it's way by the the connection of the two tubes connecting to the intake manifold. I do not see how you can adjust this clockwise or counterclockwise. ALso, even if you could do this, I don't see how it would work.

Tom W

I will be happy to supply my input on the flywheel. I'm hoping that Steve's chip does a good job, othwise I'll hear about from my wife when she drives the car. I'm also having it regeared (same 1st, 5th becomes 6th) and a LSD added. No steel synchos (too much $$ ).

I'm hoping the money results in a car that's even more fun to drive. My wife and I go to autocross school in April, I'll have plenty of feedback after that. Unfortunately this outlay delays Skippy school.

Ray Calvo

Far as I know, idle speed is controlled by the little electrons in the computer chip which send a demand to the ISV. If measured speed isn't what the setpoint is in the chip, computer sends the appropriate demand to the ISV. Nothing you can adjust or hammer with your 32 oz. ball peen - the good old days of adjusting idle speed with ascrewdriver are gone.

tom_993

I agree with Ray, but I believe that something can be done to the ISV to help with lightweight flywheels. The problem is, I don’t know what it is. My mechanic did it when he installed my flywheel. He wouldn’t tell me what he did, calling it a trade secret. “You wouldn’t want me to give away all my secrets, would you?”

Tom

Randall G.

I believe the only way to adjust the idle is through the DME's software.

I had occasional stalling after the '97 993 motor went in my '91. Todd Knighton of Protomotive raised the idle speed from about 660 RPM to 880 RPM by modifying the software (the car never stalls now). If there is an easier way to raise the idle, I imagine he would have used it.

You could try tricking the DME into thinking the A/C is always on by installing some sort of jumper. Haven't tried it myself, just an idea. Also, you might still have stalling when the A/C is actually on ... not sure. Anyway, probably cleaner just to pay a "tuner" to raise your idle setpoint, if you take the raised idle approach.

Flying Finn

OK, here comes today's stupid question: where is the chip located at?

os993

The chip is located under the driver's seat in the metal box that is bolted down with hex screws. Before you decide to fiddle with the chip, disconnect the battery. Slide the seat all the way back and you can remove all four bolts holding the box in place. You don't have to remove the seat. Once all screws are out, flip the box on its side and you will see metal tabs holding the rear box plate in place. Simply bend all tabs back and take off the plate. There you will see the chip. Be very careful pulling out the chip - use a small flathead screwdriver and pry the chip off evenly. Pulling on end too much will bend the DIP pins. Voila - chip is changed

Glen

Ok guys,here is what I know. Remove ISV,2hose clamps and one elec plug. Find the recessed adjustment screw( about the middle of the body hiding underneath a hardened rubber cement) Use a wire brush on a drill and remove the coating. Rev car up to 3000 or so and let off(where my 964 w LWF would stall ) Start to (I think back off) the screw a bit and do the rev test again. Do this until the car stops dieing on you. That has worked on a number of 964's out there and I hope would work on 95 993's...

Flying Finn

Thanks Oleg,

what should read on top of the standard chip? (= how can I tell if it is standard or not?) I wanna know before I do anything.

os993

Not sure, but if the chip has any "American" addresses, names, etc... then you know it's a non-factory chip. Weltmeister, Cynix(??), etc.. are a few "chips" out there. If it looks like a regular chip (no fancy markings, unless of course those markings are German ), you probably have a stock chip.