964 accelerometer question
02-03-2019, 09:40 AM
#16
Hello everyone!
I am new to rennlist and look for some ideas and hints concerning my 964/4 accelerator issue.
The braking issue described above was exactly occurring on my side as well. I had some "near hits" when my ABS system stopped working at full stop on the last couple of meters. You can notice it not only through the fact that the car is kind of slipping, but also that the braking pedal starts to push against you suddenly on that last couple of meters. Someone mentioned here in this thread that a warning lamp pops up or that it is possible to read-out accelerator issues with the BOSCH hammer. As far as I have observed, both is not the case. The accelerators will just corrode slowly and stop working and there is no way to detect it until it is too late... However, A. Streather mentioned in his 964 handbook, that there exists a special ABS test and diagnostic system capable to read non-plausible signals. But this tool is rare and I have never met one who has it.
So what I have done: I switched both units, but the braking problem remained. Then I put out both, cleaned all the dust and dirt attached to the magnet and reinstalled them.
Result: One still defect, the other one seems to be ok, as I can't reproduce the ABS braking problem.
So I have been in contact with John from JDSPorsche now and will order replacement soon. The only remaining question I have to you guys: Would you suggest to replace both to have consistent sensors and functionality or would it be sufficient to replace just one sensor?
Thanks in advance!
Andy
I am new to rennlist and look for some ideas and hints concerning my 964/4 accelerator issue.
The braking issue described above was exactly occurring on my side as well. I had some "near hits" when my ABS system stopped working at full stop on the last couple of meters. You can notice it not only through the fact that the car is kind of slipping, but also that the braking pedal starts to push against you suddenly on that last couple of meters. Someone mentioned here in this thread that a warning lamp pops up or that it is possible to read-out accelerator issues with the BOSCH hammer. As far as I have observed, both is not the case. The accelerators will just corrode slowly and stop working and there is no way to detect it until it is too late... However, A. Streather mentioned in his 964 handbook, that there exists a special ABS test and diagnostic system capable to read non-plausible signals. But this tool is rare and I have never met one who has it.
So what I have done: I switched both units, but the braking problem remained. Then I put out both, cleaned all the dust and dirt attached to the magnet and reinstalled them.
Result: One still defect, the other one seems to be ok, as I can't reproduce the ABS braking problem.
So I have been in contact with John from JDSPorsche now and will order replacement soon. The only remaining question I have to you guys: Would you suggest to replace both to have consistent sensors and functionality or would it be sufficient to replace just one sensor?
Thanks in advance!
Andy
02-03-2019, 10:01 AM
#17
3rd Gear
Join Date: Jun 2017
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Hi Andy
well, the ABS braking to my knowledge is only impacted by the longitudinal sensor. However, the slip control of the front-read differential is triggered by the lateral sensor. In the interest of a nice driving behavior with reduced understeer, I suggest to replace both.
JDSPorsche has a quite competitive offer - compared with the replacement parts from Porsche.
I use mine since 2017 and am very happy with them.
Krg
Uwe
well, the ABS braking to my knowledge is only impacted by the longitudinal sensor. However, the slip control of the front-read differential is triggered by the lateral sensor. In the interest of a nice driving behavior with reduced understeer, I suggest to replace both.
JDSPorsche has a quite competitive offer - compared with the replacement parts from Porsche.
I use mine since 2017 and am very happy with them.
Krg
Uwe
02-03-2019, 10:04 AM
#18
I have replaced just the lateral with solid state and been running like that for 4 years with good results.
I also moved mine forward as far as they will go, removed the bracket, moved the lateral to the front and fixed direct to the tunnel.
Principle is less lateral reaction as the pivot of the sensor is forward, and it works. Less intrusive, less activation.
I also moved mine forward as far as they will go, removed the bracket, moved the lateral to the front and fixed direct to the tunnel.
Principle is less lateral reaction as the pivot of the sensor is forward, and it works. Less intrusive, less activation.
02-03-2019, 10:16 AM
#21
I have replaced just the lateral with solid state and been running like that for 4 years with good results.
I also moved mine forward as far as they will go, removed the bracket, moved the lateral to the front and fixed direct to the tunnel.
Principle is less lateral reaction as the pivot of the sensor is forward, and it works. Less intrusive, less activation.
I also moved mine forward as far as they will go, removed the bracket, moved the lateral to the front and fixed direct to the tunnel.
Principle is less lateral reaction as the pivot of the sensor is forward, and it works. Less intrusive, less activation.
02-03-2019, 11:42 PM
#22
Race Car
Thread Starter
Originally Posted by tdiquattro
I have replaced just the lateral with solid state and been running like that for 4 years with good results.
I also moved mine forward as far as they will go, removed the bracket, moved the lateral to the front and fixed direct to the tunnel.
Principle is less lateral reaction as the pivot of the sensor is forward, and it works. Less intrusive, less activation.
I also moved mine forward as far as they will go, removed the bracket, moved the lateral to the front and fixed direct to the tunnel.
Principle is less lateral reaction as the pivot of the sensor is forward, and it works. Less intrusive, less activation.
02-05-2019, 03:06 PM
#24
Race Car
Thread Starter
That's interesting- so you gutted the center console, moved them as far forward as possible, and then reversed the location for each, so the longitudinal is now in the same orientation and location as where the lateral was and Vice Versa?
02-05-2019, 08:15 PM
#25
Yes, because getting it closer to the cars front axle pivot point was the task. So it's reading is diminished. (Longitudinal doesn't matter.)
Seems to have lessened the intrusion.
They are each same original relationship to the cars direction of travel obviously, just location changed.
Seems to have lessened the intrusion.
They are each same original relationship to the cars direction of travel obviously, just location changed.
02-06-2019, 12:57 PM
#26
Burning Brakes
Hello everyone!
I am new to rennlist and look for some ideas and hints concerning my 964/4 accelerator issue.
The braking issue described above was exactly occurring on my side as well. I had some "near hits" when my ABS system stopped working at full stop on the last couple of meters. You can notice it not only through the fact that the car is kind of slipping, but also that the braking pedal starts to push against you suddenly on that last couple of meters. Someone mentioned here in this thread that a warning lamp pops up or that it is possible to read-out accelerator issues with the BOSCH hammer. As far as I have observed, both is not the case. The accelerators will just corrode slowly and stop working and there is no way to detect it until it is too late... However, A. Streather mentioned in his 964 handbook, that there exists a special ABS test and diagnostic system capable to read non-plausible signals. But this tool is rare and I have never met one who has it.
So what I have done: I switched both units, but the braking problem remained. Then I put out both, cleaned all the dust and dirt attached to the magnet and reinstalled them.
Result: One still defect, the other one seems to be ok, as I can't reproduce the ABS braking problem.
So I have been in contact with John from JDSPorsche now and will order replacement soon. The only remaining question I have to you guys: Would you suggest to replace both to have consistent sensors and functionality or would it be sufficient to replace just one sensor?
Thanks in advance!
Andy
I am new to rennlist and look for some ideas and hints concerning my 964/4 accelerator issue.
The braking issue described above was exactly occurring on my side as well. I had some "near hits" when my ABS system stopped working at full stop on the last couple of meters. You can notice it not only through the fact that the car is kind of slipping, but also that the braking pedal starts to push against you suddenly on that last couple of meters. Someone mentioned here in this thread that a warning lamp pops up or that it is possible to read-out accelerator issues with the BOSCH hammer. As far as I have observed, both is not the case. The accelerators will just corrode slowly and stop working and there is no way to detect it until it is too late... However, A. Streather mentioned in his 964 handbook, that there exists a special ABS test and diagnostic system capable to read non-plausible signals. But this tool is rare and I have never met one who has it.
So what I have done: I switched both units, but the braking problem remained. Then I put out both, cleaned all the dust and dirt attached to the magnet and reinstalled them.
Result: One still defect, the other one seems to be ok, as I can't reproduce the ABS braking problem.
So I have been in contact with John from JDSPorsche now and will order replacement soon. The only remaining question I have to you guys: Would you suggest to replace both to have consistent sensors and functionality or would it be sufficient to replace just one sensor?
Thanks in advance!
Andy
You'll have fun with your 964 and find this forum is a good resource with great people.
My wish list has 2 of these solid state accelerometers on it and JDS have confirmed they have stock, hopefully order soon.
Yes, because getting it closer to the cars front axle pivot point was the task. So it's reading is diminished. (Longitudinal doesn't matter.)
Seems to have lessened the intrusion.
They are each same original relationship to the cars direction of travel obviously, just location changed.
Seems to have lessened the intrusion.
They are each same original relationship to the cars direction of travel obviously, just location changed.
Looks like you're doing a dash pad, centre console and carpet delete?
What have you painted the floor with and why?
I'm going down this route but currently chasing a water ingress issue...
Once that's resolved it's full steam ahead with the strip out and relocation of centre console switches etc.
tdi, do you know James aka Rephlex on here?
02-06-2019, 07:14 PM
#27
Yes James and I are good friends, I know a few of the UK crowd, L9O, 911uk, etc.
Sorry, I meant they keep the original orientation, just the lateral goes in front. Tbh the bent bit of tin they were fixed to wasn't great! The top of the tunnel is square, pretty sure a passenger in the car will screw the level reading anyway
Been working fine for 3 years
No pad as a euro/UK spec car, I was just removing soundproofing, rewiring, changing pedal box, etc, etc. Pic is old.
I did fit lightweight foam in footwells, some thin soundproofing, and a turbo cubby to the centre console. But put carpet and console back.
The paint is POR15, sets like iron! Great stuff. Mines a Targa so needs the waterproof coating under the carpets lol. (Although it doesn't leak anymore).
Sorry, I meant they keep the original orientation, just the lateral goes in front. Tbh the bent bit of tin they were fixed to wasn't great! The top of the tunnel is square, pretty sure a passenger in the car will screw the level reading anyway
Been working fine for 3 years
No pad as a euro/UK spec car, I was just removing soundproofing, rewiring, changing pedal box, etc, etc. Pic is old.
I did fit lightweight foam in footwells, some thin soundproofing, and a turbo cubby to the centre console. But put carpet and console back.
The paint is POR15, sets like iron! Great stuff. Mines a Targa so needs the waterproof coating under the carpets lol. (Although it doesn't leak anymore).
02-06-2019, 10:22 PM
#28
Race Car
Thread Starter
A note on the solid state accelerometers from JDS- http://www.jdsporsche.com/Lateral%20...%20sensor.html
I've been using them since they were first offered...or since i first saw them ...so i don't know when that was, 2011 maybe? I've installed them on other cars as well, and have driven many C4 with and without now in lots of conditions...I find them to be significantly more consistent over a variety of conditions. So I'm happy with them.
I've been using them since they were first offered...or since i first saw them ...so i don't know when that was, 2011 maybe? I've installed them on other cars as well, and have driven many C4 with and without now in lots of conditions...I find them to be significantly more consistent over a variety of conditions. So I'm happy with them.
02-06-2019, 11:49 PM
#29
For what it's worth, I gutted the central tunnel and dash area as well. I relocated my sensors to underneath the driver's seat. I have not experienced any ill effects in that location for over 2 years now and I drive my C4 hard.
