JDSPorsche rebuilt MAFs
08-19-2005, 02:09 AM
#16
Hi John,
Thank you for your reply.
No, I have no answer - sorry if my message came a bit as suspicious, that was not my intention.
I was asking since I have HFM5 MAF on my (944) S2 and it was sold to me as having no cleaning issues like the previous hot Wire MAFs', and should issues happen an ultrasonic bath could resolve the problem. I am just repeating here what the designer of this MAF kit said.
I will just wait and see if the sensor goes bad and buy another one directly at Bosch. I hope it will last more than 50k miles though
Regards,
Thom
Thank you for your reply.
No, I have no answer - sorry if my message came a bit as suspicious, that was not my intention.
I was asking since I have HFM5 MAF on my (944) S2 and it was sold to me as having no cleaning issues like the previous hot Wire MAFs', and should issues happen an ultrasonic bath could resolve the problem. I am just repeating here what the designer of this MAF kit said.
I will just wait and see if the sensor goes bad and buy another one directly at Bosch. I hope it will last more than 50k miles though
Regards,
Thom
08-19-2005, 06:11 AM
#17
Rennlist Member
Thread Starter
Hi Thom,
OK no problem. I expect if a Porsche has a problem with a HFM5 then the price might be higher than the same unit used on another make of car !
I expect Bosch will give a good price.
I do get asked quite often if I can repair these units, from Porsche, Mercedes and so on. As far as I can gather, these problems with hot film seem to start after about 60-k miles.
OK no problem. I expect if a Porsche has a problem with a HFM5 then the price might be higher than the same unit used on another make of car !
I expect Bosch will give a good price.
I do get asked quite often if I can repair these units, from Porsche, Mercedes and so on. As far as I can gather, these problems with hot film seem to start after about 60-k miles.
08-19-2005, 12:27 PM
#18
Addict
Rennlist Member
Rennlist Member
Join Date: Jul 2002
Location: Edmonton, Ab
Posts: 2,286
Likes: 0
Received 0 Likes
on
0 Posts
So, John..... given that even gross MAF dysfunction will not set a fault code, which most of us can't read anyway, how can we mortals tell if our mid-mileage MAF's are in need of attention?
08-19-2005, 12:57 PM
#19
Rennlist Member
Thread Starter
Well Brian,
Good qiuestion ! But gross malfunction will cause black smoke or reversion to limp home mode (too rich or too weak respecitively). Reversion to limp home mode will set a fault code, as I explained previously.
The main issue is how to recognise "moderate" ageing which can certainly make the car much more sluggish to throttle response, and reduce top end power. i.e. anything over 3% ageing.
A measurement of MAF voltage at idle might be useful, although the reading moves around a bit.
A 3% ageing would drop the volts from the normal 2.7v to 2.62v. But this is not something I have tried myself, as I use my calibrated flow jig to accurately compare output figures..
I can check people's MAF calibration for a nominal charge. I also offer a "try before you buy" option is someone thinks the MAF is a their problem, but are not 100% sure.
Regards
Good qiuestion ! But gross malfunction will cause black smoke or reversion to limp home mode (too rich or too weak respecitively). Reversion to limp home mode will set a fault code, as I explained previously.
The main issue is how to recognise "moderate" ageing which can certainly make the car much more sluggish to throttle response, and reduce top end power. i.e. anything over 3% ageing.
A measurement of MAF voltage at idle might be useful, although the reading moves around a bit.
A 3% ageing would drop the volts from the normal 2.7v to 2.62v. But this is not something I have tried myself, as I use my calibrated flow jig to accurately compare output figures..
I can check people's MAF calibration for a nominal charge. I also offer a "try before you buy" option is someone thinks the MAF is a their problem, but are not 100% sure.
Regards
