Frwilk Modify DME

[rporzio]

Has anyone actually used or done the modification offered by:

http://www.frwilk.com/

My car is an 84 944, runs beautifully except for the shudder on return to idle that has always been there.

[zedsn]

Hi, I have an early 944 with a Wilks chip installed and like it very much. I am running 87 octane with no know ill affects. Shudder is gone and power band kicks in much earlier at 2 grand.

[looneybin]

++ zedsn - same here, best $200 spent
Only draw back is a slight reduction in gas mileage, but thats probably my fault for keeping my foot in it more.

[Eldorado]

best 350 i spent on my car - i agree.... just for the shudder fix if anything! (mine was more because it's an early 944).
i dont notice any gas mileage difference....
and I too run 87 with no ill effects.

good product and well worth the money.
does it increase hp? not much... but it does make it more smooth to drive.

[Amet_944]

Originally Posted by Eldorado

best 350 i spent on my car - i agree.... just for the shudder fix if anything! (mine was more because it's an early 944).
i dont notice any gas mileage difference....
and I too run 87 with no ill effects.

good product and well worth the money.
does it increase hp? not much... but it does make it more smooth to drive.

When I checked his site yesterday I saw that he suggests buying a BMW DME and replacing one of the boards to allow for the use of a early chip.

[rporzio]

Ok so here's the question.

I want to stay stock, if I buy an 87 DME/AFM combo can I just use wilk's stock chip for $17 with no other modifications?

Or, is that chip only for using the BMW ECU modification to my existing DME and AFM?

Or, do I have to buy the more expensive chip ($200) and the 87 DME/AFM combo which suddenly makes getting rid of the shudder a nearly $500 project.

I must mention that my car runs beautifully with the one exception of the return to idle shudder that has been there since I bought the car new.

Thanks so much for everyone's contributions, I am really enjoying this forum.

[white944cup]

If you like the way the car runs the way it is, why buy a chip just to fix the shudder. This is FRWilks procedure (posted long ago on this site and on his website) for adjusting the shudder out of the system. I did this adjustment to my '84 and it worked great, totally eliminated the shudder with no apparent side effects. Made the car much more pleasnat to drive, especially in stop-and-go traffic, where the shudder really showed itself as a PITA. Enjoy!

What is the "944na shudder"? Every time you close the throttle from above
2,000RPM, the engine drops below the normal idle of 950RPM down to 600RPM
and then back to 950RPM. The engine performs a violent shudder. The
intensity of the shudder may vary and many 944na Porsche do not have the
problem.
NOT THE CAUSE:
Response cams, spark plugs, vacuum leaks, motor mounts, and auxiliary air
valves will not cause this shudder. They can cause idle problems or engine
shaking but have nothing to do with this specific problem.
THE CAUSE:
On deceleration, the overrun [coasting] fuel cut-off frequency is too close
to the idle frequency. In other word, fuel is cut-off when the throttle is
closed and does not start up again until the engine drops below 1,200RPM.
Fuel does not start up soon enough to keep the RPM from dropping below
normal idle. The overrun fuel cut-off frequency should be set higher at
1,600RPM. It is designed to save fuel. Mine dropped to about 600RPM with a
nice big shudder.
THE CURE:
The overrun fuel cut-off frequency is internal to the DME. If the
throttle-closed signal is never received, the overrun cut-off will be
eliminated. This is a simple trick to fool the DME into ignoring the
fuel cut -off. The software fix is beyond the capabilities of most,
but this simple adjustment, anyone can do.
THE PROCEDURE: Revised 5/2001
Do not continue if your engine is not in good working order. Fix it first.
With the engine off, take an 8-mm box wrench and loosen the nut on the
throttle stop screw. Operate the throttle so you hear the click. Turn out
the stop screw until the click stops. Turn the screw out about a quarter
tun past that point. Tighten the nut and lock it down. Start the engine and
turn the air bypass crew in to adjust the idle down. Set it a little high
at about 1000 RPM. What you have done is completely eliminate the
throttle-closed switch. Simple, maybe 15 minutes.

[rporzio]

OMG, the shudder, that I've lived with for 23 years, is gone!!!!!!

Well done "whitecup944"... He furnished the hands on fix that has saved the day.

[thoen]

Wilks is the very best and added real zip to my 1983. i changed the dme and the air flow unit to a 1987 model and used the wilks plugin for the late 944. WOW!!! nice change.

[Eldorado]

it's literally the best, and easiest, 'fix' for the 944.. dollar for dollar, time for time to install.

you really feel it in the butt dyno.

[white944cup]

I'm glad it worked for you.....pretty easy, huh? BTW, I love the look of your early 944 with the white Fuchs.....the car looks great. Here's a picture or mine before I sold it to Rcecale. He's lovin it............