I have a 1991 LHD 964 Turbo 2. When I bought is 18 months ago, there was a slight hesitation and a slightly "edgy" push in the back with the turbo on boost.
This was quickly diagnosed and corrected - but not quite. This has been the case 3 times since now. It's driving me batty. Each "correction" improves the performance (I suggest by means of improving something else but not addressing the root cause) - but that slight uneveness remains.
I have had the metering unit, injectors and regulator all renewed by Bob Watson.
I have had the wastegate replaced by a Tial unit, a manual boost control fitted, the bypass valve renewed, secondary fuel pump renewed and an electrical supply to the FI (not sure what) by Jon Mitchell.
In two further attempts to locate the problem, Jon replaced the cap, the rotor, checked and renewed the ignition ends, replaced various vacuum pipes, intake-to-intercooler seal and blanking caps.
The ignition leads were replaced in 1994 at the Stuttgart factory, but have done only 20,000 km since. These were measured by Jon as nearing the upper limit of the resistance range but not outside the range.
Another specialist near me thinks it very unlikely that the leads will be the problem - not impossible, but down the list of other causes. So, I am loathe to swap the leads on another goose chase (over £450 fitted); OK if I was confident that this would fix the problem.
The boost is set to about .85 - so fairly modest and shouldn't be "blowing out" the spark.
Has anyone any ideas what the problem could be? And who could you recommend me to take the car to? I live near jn 17 of the M4. Bob Watson is quite some drive from me; likewise Jon Mitchell. There's also Autofarm and Northway, both of whom are nearer. I'm really looking for someone with good experience of the Turbo 2.
Many thanks to anyone suggesting ideas of who/how to track down and cure this.
Iain.
This was quickly diagnosed and corrected - but not quite. This has been the case 3 times since now. It's driving me batty. Each "correction" improves the performance (I suggest by means of improving something else but not addressing the root cause) - but that slight uneveness remains.
I have had the metering unit, injectors and regulator all renewed by Bob Watson.
I have had the wastegate replaced by a Tial unit, a manual boost control fitted, the bypass valve renewed, secondary fuel pump renewed and an electrical supply to the FI (not sure what) by Jon Mitchell.
In two further attempts to locate the problem, Jon replaced the cap, the rotor, checked and renewed the ignition ends, replaced various vacuum pipes, intake-to-intercooler seal and blanking caps.
The ignition leads were replaced in 1994 at the Stuttgart factory, but have done only 20,000 km since. These were measured by Jon as nearing the upper limit of the resistance range but not outside the range.
Another specialist near me thinks it very unlikely that the leads will be the problem - not impossible, but down the list of other causes. So, I am loathe to swap the leads on another goose chase (over £450 fitted); OK if I was confident that this would fix the problem.
The boost is set to about .85 - so fairly modest and shouldn't be "blowing out" the spark.
Has anyone any ideas what the problem could be? And who could you recommend me to take the car to? I live near jn 17 of the M4. Bob Watson is quite some drive from me; likewise Jon Mitchell. There's also Autofarm and Northway, both of whom are nearer. I'm really looking for someone with good experience of the Turbo 2.
Many thanks to anyone suggesting ideas of who/how to track down and cure this.
Iain.
