matt777

I've mentioned in a number of posts that I still had stalling issues after installing a LWF. Also, when coming to a stop the idle speed would bounce around to as it had difficulty finding idle. I adjusted and cleaned the ISV, installed new plugs and adjusted my driving style which helped a bit. Installing a Steve Wong/911 chip with the LWF mod got rid of most of the stalling but not all of it. At the suggestion of Mark @ FD Motorsports I bit the bullet and bought a new ISV from him. The engine hasn't stalled once in 4 outings even when I reverted to my old driving style of depressing the clutch at 3000 rpm when coming to a stop instead of waiting until the rpms dropped to 1000. The engine speed drops down to below 800 rpm but quickly finds a steady idle now too. YRMV

Van Larson

Good news indeed. Did you "adjust" the new ISV setting at all before install (i.e. clean out the gook from the 2 set screws and turn plastic "dial" a couple of degrees)? I don't stall often but on warm start up, idle "hunts" up and down several times before settling in steady. I am also going to send my Wong 91 oct. LWF chip back for his latest reflash (will probably do 1st as an experiment to see what "effect" the new flash has) before installing my new ISV purchased from FD.

matt777

If you have been adjusting your ISV I suggest putting it back in the original position when trying a new ECU chip. On the new ISV I did clean out the resin plugs and break the set screws loose and retightened them so I could adjust it without removing it again. I didn't need to.

nile13

Matt, did any of the 4 outings include headlight and/or A/C being on?

mongrelcat

Congrat's, Matt.

matt777

I ran both the headlights and AC on one trip. My HID headlights are on a relay though (if that matters). Perhaps I can report back in another month once I log a few more miles but there is obviously a big improvement.

matt777

Thanks. It will be nice not to have to worry about stalls.

nile13

Matt, that sounds great and really encouraging. Thanks and congrats!

Mark in Baltimore

Excellent data point, Matt. Thanks for sharing.

trophy

That is great Matt, I bet you are back to enjoying your car

matt777

I am. How far away is your car from being back on the road Steven?

95 C4 993

I cant say Im a believer that a new ISV will fix the issue---generally speaking. With over 70 percent of all 95 993's stalling with a LWF, that is saying over 70% of ISVs are bad or could be a contribuating factor to stalling.

My 993 hasnt stalled in least a dozen outings---its rare and when it does happen, it usually happens back to back to back----2 to 3 times stalling in a row.

Been driving my 993 the last couple of days, with the AC on, and no stalling. Even put new rear tires/wheels today and no stalling. New tires dont seem to contribute to stalling---I have rulled that out with several sets of tires over the years. Ok, that was being sarcastic. :-)

Generally speaking, my 993 is more prone to stall with the AC and/or lights on. Thats speaking from 7 years with the LWF and several trips and thousands of dollars in work tweeking this, that, and everything under the moon, smoke test, plugs, wiring, ISV cleaning--you name it, I have done it.....and I still get the ocassional stall.

Been around the block for serveral years with the LWF and stalling---could right a book on it. I have given up and learned to deal with it. Each of the dozen or so trips to the shop, I would drive for sometimes weeks, or even months with no stall only to be sucker punctch by the demon the LWF has become. Its a love hate relationship: The the performance and feel but I want to shove my fist through the windshield when it stalls.

Oh yea, took about a year not thinking about the stall when driving. You think it about it all the time when driving.

Rinty

mongrelcat

How do you know unless you try it? You say the same thing in threads where a Wong/Weiner chip solves the issue for someone. You've never tried a Wong chip as I recall.

Some 993's are 18+ years old. How many have the original ISV? Almost all. Who's to say there wasn't a slight revision to the design of the ISV overs the years? Or that having one that's clean as a whistle doesn't work quite as well as one that's new?

jakfrost

"Or that having one that's clean as a whistle doesn't work quite as well as one that's new?"

I have to say I tend to agree with '95 C2 993' to a certain degree...I have tried a number of 'fixes' including a Steve Wong Chip...AND I have cleaned my ISV to the point it squeaks! More than once! Maybe it didn't 'whistle' but it was as clean as a new one in my estimation.

Not to say that I wouldn't be tickled to death if simply swapping it out for a 'new' one would ELIMINATE the issue .

How much was the new valve?

Jim