Long Term Tozo Valve Body Modification Update
04-19-2007, 05:11 AM
#11
AudiWorld Super User
Thread Starter
Facelift climate control
It's been installed for a long time, works great, had to put a AC compressor switch in to turn the compressor on.....and I lost the temperature reading in the dash because it is on the CAN bus which my car doesn't have.
04-19-2007, 07:29 AM
#15
AudiWorld Super User
Thread Starter
Agreed
When Gabor did the stage I mod for dropout, I could tell that the TC was locked up (actually should say slipping) at a much lower slip number than stock. Locked pretty hard (virtually no slip).
This could be seen in vag-com also.
He adjusts something else (they wouldn't even let me know) in the valve body to compensate for the hunting versus the highway drop out.
When Eddie went for a test drive with me last night so I could show him that the hunting was still present, he said in about 2 seconds "it's the throttle position sensor" as most are adjustable. We showed him the idle switch and how it worked, and that it was adjust correctly.
On a GM car, they would just advance the TPS so it gave a higher throttle position and that would settle the control units down.
So either a 400 ohm resistor in series with the thing (that's my idea) or one more adjustment and we might get rid of the hunting.
This could be seen in vag-com also.
He adjusts something else (they wouldn't even let me know) in the valve body to compensate for the hunting versus the highway drop out.
When Eddie went for a test drive with me last night so I could show him that the hunting was still present, he said in about 2 seconds "it's the throttle position sensor" as most are adjustable. We showed him the idle switch and how it worked, and that it was adjust correctly.
On a GM car, they would just advance the TPS so it gave a higher throttle position and that would settle the control units down.
So either a 400 ohm resistor in series with the thing (that's my idea) or one more adjustment and we might get rid of the hunting.
04-19-2007, 02:22 PM
#18
Your workaround resistor might be enough to keep it from hunting, but it's bad for science
Its absence is obviously not what made it start hunting.
And if your engine load/torque numbers don't agree with those of a non-hunting car, you'd have that lead to follow.
Still, the resistor might do the trick...
There must be a good explanation of how things now being adjusted in the transmission could have been completely good enough to prevent hunting one day then completely bad enough to cause it the next day. And there must be another good explanation of how, if your hunting and highway-speed coasting dropout turned up together, they can be properly fixed separately.
Without such explanations, there's a nagging suspicion that some of the valve body work -- especially the earlier "bias it toward lockup" approach -- is like your proposed TPS resistor in terms of not specifically addressing underlying causes.
I lack the insight to come up with such explanations, but don't doubt Gabor's determination or ability to understand and implement a complete, in-spec fix. There's probably nobody outside ZF more familiar with the problem!
Tom
And if your engine load/torque numbers don't agree with those of a non-hunting car, you'd have that lead to follow.
Still, the resistor might do the trick...
There must be a good explanation of how things now being adjusted in the transmission could have been completely good enough to prevent hunting one day then completely bad enough to cause it the next day. And there must be another good explanation of how, if your hunting and highway-speed coasting dropout turned up together, they can be properly fixed separately.
Without such explanations, there's a nagging suspicion that some of the valve body work -- especially the earlier "bias it toward lockup" approach -- is like your proposed TPS resistor in terms of not specifically addressing underlying causes.
I lack the insight to come up with such explanations, but don't doubt Gabor's determination or ability to understand and implement a complete, in-spec fix. There's probably nobody outside ZF more familiar with the problem!
Tom
