Prob with my '96 VR6 - please help!

[Golf Loon]

I think they say they are sealed cos a layman can bugger up the settings easily.

[h100vw]

The only sealed bit is the position sensor. They would normally be sealed to stop the **** getting in causing failures.

There would normally be a throttle closed and wide open resistance to allow the ECU to know when to idle and when you are after full steam. The resistance in between giving the load to the ECU.

What often happens is that after years of driving round at the posted speed limits, the tracks in the TPS getting dirty at certain places which correspond to the throttle required to maintain particular road speeds.

When you open or close the throttle past this position the ECU would get an inaccurate signal, maybe one which tells it to cut the fuel as it should be at tickover, this would also kill the timng too. Big loss of power would happen until you get back to a place where the signal is again valid. I see this quite often at work on various aircraft instruments and sensors. In the workshop we can strip and clean the offending parts before testing and certifying them. We usually clean them up with brasso and a squirt of contact oil for lubrication and to stop oxidation.

The way to check it would be to find the varying resistance on probably 2 pins of the TPS and monitor this resistance with a meter while opening the Throttle very, very slowly looking for sudden jumps in resistance or open circuits. I would expect the TPS to run from close to zero to maybe 2-300 OHMS over the full range of movement.

If you get problems again it may be a case of repalcing the TPS with the one from the spare TB. You still need to set the TPS correctly so the ECU knows where it's at.

In more modern Dubs this would be a TB adaptation.

Gavin