964 rough idle at cold after steve wong chip

[hepkat63]

Hi,
I have just purchased a Steve Wong chip for my 1990 C2 Tiptronic. After installing it - the car is having all sorts of issues when I start it cold.

I used to be able to start it cold, it would idle perfectly. Now, when I start it - it dies two or three times before finally idle very rough. When I put it is drive - it dies again. I

I have to use two feet on the pedals to keep it going. Once it warms up after a few minutes, it seems fine.
On the open road it is fine - no issues - although when Idle at hot - it still seems a bit 'surge'.
I realise that the car needs to be driven for 15 minutes to reset/learn the DME - but I have taken it out twice for over 1/2 hour and it is still the same.
The car was used to idle perfectly on the stock standard chip? Any thoughts please?
regards
steve

[Arrowhead]

You could have gotten a bad chip, it happens.I put a Steve Wong chip in my 1991 Tip and it worked fine. Try putting the stock chip back in just to make sure it's the Wong chip or something else happen. Make sure you did not bend one of the chips points and it's in all the way.

[hepkat63]

thanks Arrowhead... yes, it is definitely installed correctly (no bent pins) and putting the stock one it - there is no issue. Never known the Steve Wong chips to be defective though?

[porterdog]

NEVER read a bad experience with those chips. Contact the man himself; I bet he'll be very helpful.

[hepkat63]

yep, have contacted via webpage - no reply as yet.

[ischmitz]

For what it's worth: If a chip (EPROM) was put in wrong (even one bent or broken pin) or damaged in the process the car would not start at all. And similarly, if any content inside the chip was bad the car would not start at all. It's a very black & white picture.

So the only possible explanations are:

- the specific chip is not compatible with your setup
- you have something else not working properly (vacuum leak, sensors, fuel pressure, etc.)

The simple test is to swap back to the stock chip to confirm nothing else coincide with you putting the SW chip in. The "learning" is an adaptation of the volumetric efficiency of the engine at idle. This function relies on a perfectly working O2 sensor and takes a fully warmed up engine to drive around for some time. After that the mixture is adjusted ever so slightly with a trim value to maintain a stoichiometric mixture at idle (as seen by the O2 sensor).

The 964 Motronic chip has multiple maps that are chosen based on the personality jumpers on the DME harness. These jumpers are set based on region, manual vs. tip and O2 sensor Yes/No. Some aftermarket chips ignore these jumpers altogether by bending all vectors inside to the one modified map set while other chips have all individual maps changed.

There are differences between the manual map and the Tiptronic map to account for the specific behavior of an automatic transmission (torque converter is dragging the engine instead of a clutch completely unloading the engine). If these jumpers are ignored in an aftermarket chip drivability might suffer.

Ingo

[Busta Rib]

This is why Pelican rocks. Nicely done, Ingo.

Originally Posted by ischmitz

For what it's worth: If a chip (EPROM) was put in wrong (even one bent or broken pin) or damaged in the process the car would not start at all. And similarly, if any content inside the chip was bad the car would not start at all. It's a very black & white picture.

So the only possible explanations are:

- the specific chip is not compatible with your setup
- you have something else not working properly (vacuum leak, sensors, fuel pressure, etc.)

The simple test is to swap back to the stock chip to confirm nothing else coincide with you putting the SW chip in. The "learning" is an adaptation of the volumetric efficiency of the engine at idle. This function relies on a perfectly working O2 sensor and takes a fully warmed up engine to drive around for some time. After that the mixture is adjusted ever so slightly with a trim value to maintain a stoichiometric mixture at idle (as seen by the O2 sensor).

The 964 Motronic chip has multiple maps that are chosen based on the personality jumpers on the DME harness. These jumpers are set based on region, manual vs. tip and O2 sensor Yes/No. Some aftermarket chips ignore these jumpers altogether by bending all vectors inside to the one modified map set while other chips have all individual maps changed.

There are differences between the manual map and the Tiptronic map to account for the specific behavior of an automatic transmission (torque converter is dragging the engine instead of a clutch completely unloading the engine). If these jumpers are ignored in an aftermarket chip drivability might suffer.

Ingo

[hepkat63]

Originally Posted by ischmitz

For what it's worth: If a chip (EPROM) was put in wrong (even one bent or broken pin) or damaged in the process the car would not start at all. And similarly, if any content inside the chip was bad the car would not start at all. It's a very black & white picture.

So the only possible explanations are:

- the specific chip is not compatible with your setup
- you have something else not working properly (vacuum leak, sensors, fuel pressure, etc.)

The simple test is to swap back to the stock chip to confirm nothing else coincide with you putting the SW chip in. The "learning" is an adaptation of the volumetric efficiency of the engine at idle. This function relies on a perfectly working O2 sensor and takes a fully warmed up engine to drive around for some time. After that the mixture is adjusted ever so slightly with a trim value to maintain a stoichiometric mixture at idle (as seen by the O2 sensor).

The 964 Motronic chip has multiple maps that are chosen based on the personality jumpers on the DME harness. These jumpers are set based on region, manual vs. tip and O2 sensor Yes/No. Some aftermarket chips ignore these jumpers altogether by bending all vectors inside to the one modified map set while other chips have all individual maps changed.

There are differences between the manual map and the Tiptronic map to account for the specific behavior of an automatic transmission (torque converter is dragging the engine instead of a clutch completely unloading the engine). If these jumpers are ignored in an aftermarket chip drivability might suffer.

Ingo

wow! thank you !

[Shamus911]

A friend of mine recently installed the SW chip and didn't have it fully seated. He thought it had, but it hadn't, and when he attempted to start the car - it turned over but wouldn't fire. Seated it fully and voila - she lives!

Just one more data point. Good luck!

[racerx9146]

I have a Wong chip in my 3.6 conversion and also have a slightly surging idle. Steve confirmed for me his maps ignore the jumper. I am gonna try an adaptation.

Daron

[hepkat63]

Originally Posted by racerx9146

I have a Wong chip in my 3.6 conversion and also have a slightly surging idle. Steve confirmed for me his maps ignore the jumper. I am gonna try an adaptation.

Daron

Hi Daron,
mine is doing this too - very occasionally and usually after it has warmed up. Please post what you find to fix this.

[Hamptonsam]

Mine needed adaptation before it started working better.

[kgb_kgb]

Just a quick question . Can we just dyno the car and get a custom map or do we need the chip ?

I have a 964 C2 trip