The dreaded MK3 limp mode in 5th gear

[chewy8000]

So we ran a test day and had great success in the new car (95' ITB golf). I had one issue that was consistent with a few of the new mk3 vw golf builds. The car reaches 5200 rpm in 5th gear on the straights and cuts out for 2-3 seconds. I know the issue is with the VSS sensor on the tranny and it's connection to the ECU. Conover Motor sports was aware of this and ran a jumper wire from the sensor straight to the ECU as a preventative fix but it's still happening. Is there anything else to check besides having the ECU bench tested? It's super anoying and surely killing my track times.

[Beran]

It could be the ECU programming - happened to Tim... they forgot to remove or change the top speed limiter.
If that is not it then it could be fuel related... Do you have a new fuel pump? I had that problem for a little while... old tank with old gas and crap in it sitting for so long that it just screwed my pump up enough not perform well enough to keep up.
just some .02
Beran

[jlinfert]

ECU's are free now. Dump the POS factory ECU and install a Megasquirt2 system. I believe there is a tremendous untapped potential in the ABA that a factory ECU is unable to access. Just my .02.

[jlinfert]

ECU's are free now. Dump the POS factory ECU and install a Megasquirt2 system. I believe there is a tremendous untapped potential in the ABA that a factory ECU is unable to access. Just my .02.

And by the way we(Atlantic Auto Works) are now installing and tuning Megasquirt systems starting at $1400 COMPLETE! (This includes dyno tuning) 321-254-1344

[chewy8000]

Thats tempting but too far away.

[jlinfert]

You might check the VWVortex Carbs,ITBs and SEM forum I believe there are a couple of Megasquirt installer/tuners in your area. Several of them are very very sharp.

[Dave Zaslow]

VAG (now VCDS) the car. Any limp mode will inflict this limiter on you.

Make sure the VSS itself is good. It's read by pins 1 and 65 on the ECU. Ignition on, neutral selected, raise the left front wheel and turn (lift both wheels if diff-locked together). It should fluctuate between 0 and 4 volts.

Check the continuity of the jumper as well, just in case...

Where did the chip come from?

DZ

[chewy8000]

We ran the stock chip in it for the test day. It had more gains at the dyno than the Techtonics chip we tried using.

[spnkzss]

What is the top speed limit in a stock ECU?

[chewy8000]

I need to either drop some money on megasquirt/tuning or buy a VAG-COM for this thing.