The dreaded MK3 limp mode in 5th gear

[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.

[Dave Zaslow]

This situation brings back so many bad memories chasing this stupid thing.....

Not likely, but one other item the ECU is sensitive to is a spanking clean signal from the O2 sensor. Hook up a voltmeter and watch the rise and fall of the voltage. Hook up an oscilloscope and see if the signal is clean.

Take a look at the behavior of the injectors when you rev the engine (you can do this in the shop). If you are getting injector open times of 10-15ms or larger, you are hitting the full rich, dump as much gas as possible to save the engine, ecu limp mode.

BTW is this OBD1 or 2?

If you will share the dyno results I can send you both GIAC and TT chips mounted and ready to go in an OBD1 ecu. Both ostensibly custom, but not Dick Shines later creation. Plug and Play guy?

DZ

[chewy8000]

Thanks Dave,

The motor is OBD-2. I tried to contact Garret but he's impossible to get in touch with and there is no phone number on his site.

[dave parker]

Shine Racing Service phone number is 508.695.8888

cheers
dave parker

[Dave Zaslow]

All the stuff I have is OBD1.

One of the craziest reasons I have heard for this problem was a cracked crank trigger wheel that deformed at higher revs only That caused the crank trigger to lose signal and you know what happens then.... They had to pull the crank and change the wheel. If Cameron built the engine I'm sure he used a new one to avoid this.

If you want you can call me at work. http://bodouva.com/index4.html

DZ