Smokin

Okay... I may step into a pile of it but I'll throw in my 2 cents... Wrong though it may be... Jagerocks needs a driveable car. I had the same problem with my P-car and there was a cheap, partial solution.
I won't go into a long explaination about everything that has been done to my car. You can search my earliest posts to see a list.. a few years ago I think. I purchased my car over the Internet about 3 years ago. I saw pictures from 30 angles and was faxed all the repair orders covering all repairs and mods. (In the prior 5 years the PO spent more in modding it than I paid for the car.) It was (and still is) the cleanest Porsche I've ever seen. It's also the fastest non-turbo I've ever driven. It was basically rebuilt to RS specs by Andial in California. I'm sure the PO tracked the car occasionally. Andial installed a Club Sport LWF and installed a chip. I'm not sure of the brand chip... There is just a part number on that repair order. (AND 618 111 00) This car has the same issues as (almost) all describe when they swap in a LWF. On the back of the repair order is stapled a page entitled, "Idle Stabilization For Lightweight Flywheel Installation"... Then it goes on to say.. "Use a piece of 1/4" black rubber washer hose. Cut approx. 1/4" piece. Slide this rubber hose onto the throttle cover where it makes contact with the idle micro switch. Be sure rubber does not interfere with the bracket." It also has a cheesy diagram drawn.

Now this seems like a cheap fix for a problem that shouldn't exist. I agree that you should probably not install a LWF on a C2 that it is not made for. However... I must say that it would not have stopped me from purchasing the car in the first place. The above recommendation seems to work enough to make the car driveable... Except on cold mornings as was relayed in a prior post... I let mine warm up too. The problem is more apparent in the winter... But almost disappears in the summer. I offer this solution not as a way to "fix" the problem... But as a way to make the car driveable enough until it can be fixed properly. My car is a garage queen... I'll get around to swapping the correct flywheel in one of these days... I'm in the process of starting a new business and don't have the time or money right now. On mine... with the rubber hose filing the gap between the micro switch... I need to wrap a little black electrical tape as an "adjustment" to adjust the idle. In the winter I wrap a little extra tape around it... In the summer I take a little away. I know that this is a poor way to manage this issue and, like I said... I'll swap out the LWF for the correct one as soon as possible.

BTW... If anyone knows exactly what the chip number above means please let me know. It looks like an Andial chip... I was curious if it is something they sell for LWF or if it is just a performance chip that goes with the RS cam they installed.

Thanks!

jagerocks

1990 Guards Red Carrera C-2 - Highly Modified - Smokin
2002 BMW 325xi
2003 Nissan Murano ,

I called Autothority to see about the fix of the LWF they installed. As it is they have a fix and so does Andail, it is to install a chip and modify the ISV. I have just modified my ISV and have installed another brand of chip. I will see in the next days or so if this works. I don't have time tomorrow to check it out. But it sounds like your on the same track as me. I will let you know what I come up with.

Thanks Jason ( jagerocks)

jagerocks

Autothority wants $795usd for the "their" chip and "their" ISV modifcation. I did mine in about 15minutes and was free.

Jason
(jagerocks) 1990 C2

Michael Gibney

Earlier I mentioned a simple solution, not my idea, has been done by Toyota and I expect many others, see the attached image from Toyota workshop manual for 22R engine, it would be interesting to hear from anyone who has any comments as to why such a simple inclusion as a "dashpot" would not work, ok the 3 seconds may be too long, commonsense tells me the dashpot must have a hole that exhausts air when the bellows move, surely this could be enlarged a bit at a time with number drills until the time is shortened to a delay that is just long enough for the ECU to "catch its breath". Simple and anyone who has tinkered with cars, or fettled with them for you Brits, would have no trouble and a bit of good clean fun making the dashpot fit in place.

So please lets for the sake of a bit of creativity and out of respect to the many who like to tinker forget the insurance and big brother issues and lets hear some comment regards "will it work".


Finally, I'd try it myself but until I get a LWT flywheel installed it would be a non event and then knowing my luck I would have one of adrian's 25% that are ok.

Regards,

Michael Gibney

Michael Gibney

Woops, not very good at computers, try the image again

jagerocks

As my last decussions about my stalling problem I now have just installed the ISV after cleaning and modified the adjusting screw. Also at the same time I installed a K&N cone air filter. NOW idle is too high. When I adjust the ISV in or out all the way nothing happens. Engine idles at 1500/2000 RPM. The problem was origanaly to help the stalling after install of lightenedflywheel. I have also installed DME chip to help (but made no difference). Also at this time I changed the oil. I heard something about engine oil over flow???? what is this? I'm sure I have the correct amount of oil.
Jason (jagerocks)
1990 911 C2 3.6L

jagerocks

DOES ANYONE KNOW WHAT THE BLACK CANISTER IS BY THE AIR FILTER HOUSING? IT HAS A VACCUM LINE HOSE TO IT. I ACCEDENTLY PULLED THIS OFF WHILE CHANGING TO A K&N AIR FILTER CONE. WHEN IT CAME OFF I HEARD THE VACCUMM LOSS SUCK. I JUST FIGURE IT WOULD TAKE VACCUM AGAIN AT START UP. MAYBE THIS IS MY PROBLEM WITH HIGH REV'S NOW?? 1500-2000 RPM.

THANKS JASON
1990 911 C2

kris

This is what Adrian said about this a few days ago. Good luck
The carbon cannister is fitted to all 964s. Most owners have no idea they are even fitted let alone where they are fitted (tucked up under the left rear fender).
The job of the carbon cannister is to collect up the fuel vapours via the tank venting valve.
Every now and again these fuel vapours are purged and sent back into the engine. This is all done basically when the engine is cold.
The problem is that as with everything including 964 owners age creeps up. The carbon will (and has) started to break up. Eventually the lines become blocked.
Now I am not suggesting for one minute that this is your problem. It is something to look at when all practical suggestions have been dealt with.
There are six areas in the 964 which owners will need to start looking at as they age past 15 years;
Air bag age limits which is nothing to do with this discussion.
Carbon cannisters.
Vacuum lines.
Air-intake lines.
Oil breather lines.
Fuel lines.
Ciao,
Adrian.

kris

Oops, you mean the canister on the air box That's a different one than the one I'm referring to which is in the rear tyre well.

Adrian

No it isn't
Ciao,
Adrian

Dunasso

I've been following this thread and I must admit that the material covered on this subject has done little to enlightened me.

I still have no idea why my particular situation is without incident or consequence.

So, I ask again to anyone who may have a reasonable answer; if there are so many people having these problems of stalling and erratic engine surging, then why not me?

My car is a stock 1991 NB 964 Cabriolet with LWF, Authority chip, and MAF. That's all. I haven't even performed the ISV adjustment. Does anyone think that I should make that ajustment anyway?

Duncan

Adrian

Dear Duncan,
If it ain't broke why the hell try and break it
I posted what would happen if the ISV adjustment was played with but nobody was listening
Nobody can answer your questions without ripping your car apart and taking a look especially at the part number of the flywheel and the programming of the chip. Maybe the flywheel has been weighted.
As has been said, about 25% of these LWF installations do not have a problem and there is no logical explanation for this apart from the fact that I suspect some of the professionals who do this work do weight the flywheel until it co-operates.
A bit like balancing a wheel.
Ciao,
Adrian.

Lorenfb

Adrian is right-on with his comments. I, as he, have seen many 964s with this problem
in working with many Porsche independent shops and dealers. The problem is there for
the majority of cars with a LWF << stock. It's hasn't been solved properly yet by methods
other than a re-work of the DME microcode, i.e. mod ISVs, special performance chips,
& etc. haven't worked.

JasonAndreas

Duncan,
This past Saturday was the first time I've driven with a LWF and an ambient air temperature above 45F. Up until now the air temperature has always been below freezing (including when I did the engine drop in an unheated garage last December) and I've had some very minor but annoying stalling issues. I had absolutely no issues this weekend or today (knock on wood). The only differences are the air temperature and a freshly charged battery. I put the battery in and didn't bother running a system adaptation but the idle never bounced while driving when the car would come to a stop. I don't even remember it dropping below 800 except for when I first started the car and I drove at least 150 miles, most of which wasn't on a highway. I have a stock eprom, AFM (no MAF), an unmolested ISV and a genuine RS LWF. It will be interesting to see what happens when its actually warm outside.

AJKOK1

If only all our 964s were exactly the same spec, I guess these kind of conversations would be a lot briefer.

My 1990 C2 had a lightweight flywheel fitted, supplied by 9m. I had it fitted and found it was a bit prone to stalling, the only change suggested that I undertook was to have all my injectors cleaned, that was done and since then it has been fine.

I suffer for the first 2 mins of a cold engine, so as long as I let the car sit first thing in the morning and allow a bit of heat to develop before i drive off, i have absolutely no issues.

Now I am no automotive expert, but I just wonder if maybee the differences we see are down to (a) The exact weight of the flywheel (my kit advises it save 8kg from the stock DMF) and (b) the components it is fitted with. In the case of my flywheel the kit included :-

1 x RS Flywheel
9 x Flywheel to crankshaft bolt
1 x Clutch centre plate
1 x Clutch pressure plate
1 x Clutch release bearing
1 x Flywheel spigot bearing (nose bearing for gearbox input shaft)
1 x RS starter ring gear
1 x Modified guide tube for release bearing
9 x Clutch cover to flywheel bolt

The above may well be totally as you would expect, but maybe something listed above will stand out to a more technical reader who will say "ah, didn't change that bit".

I'm not on commission, but this is the link to the kit from 9m, so it may help highlight an obvious difference.

http://www.9mracing.co.uk/html/modules.php?op=modload&name=Shop&file=index&req=viewproduct&productid=76 2&quickview=1

I wish I could provide more sound advice ( I am concious that I get more help from rennlist than I put back back in with technical advice).

To be honest having read all these threads, as a newbie reading it for the first time I would not go within a million miles of a LWF, but as a driver of a car with it fitted, its made a big difference to the perceived responsiveness and charactor of the car.

Al.