MAF Replacement Cured Hesitation
03-22-2004, 12:12 PM
#1
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MAF Replacement Cured Hesitation
Greetings:
I have been trying to isolate a hesitation issue for the last year.
The car is a model year 85. New coils, wire set, caps, rotors and plugs all as a point of general maintenance did little to improve the hesitation in the upper RPM range just as the engine came "on the cams". I went to a rising rate fuel pressure regulator and this helped as I dialed up the fuel pressure. But I was unable to get the hesitation completely out of the vehicle. I have an ARM air/fuel ratio gauge and the engine never appeared lean, but that was the consistent feel I had while pushing.
For reference I Have an Authority Chip set, custom 3 inch insulated intake runners, modified air box ( I have smoothed the walls and built a radius in the floor of the box to help the air turn into the throat of the MAF) , stock manifolds wrapped with header wrap, gutted cats and a 3 inch exhaust. The exhaust is also wrapped from the manifolds to the exhaust tip.
No air pump, No AC, belt fan replaced with an electric.
In an exchange of e-mails with John Speake, he was extremely helpful in
providing valuable information which led me to the conclusion that the MAF had finally given up the ghost. According to John a 2% error in the Maf can cause a 10% lean issue with the engine. My raising the fuel pressure with the Rising Rate Regulator was just helping to compensate for the out of calibration MAF. John provides a recalibrated exchange for $450 with a $100 core fee which is refunded upon return of your used MAF.
I ordered a MAF from John. The first thing I noticed was just an improvement in the off throttle driveability. I've had my 928 for 9 years. I think we lose perspective as some items slowly deteriorate. The car is now more of a pleasure to drive than it has been in several years. Throttle response is much improved and the noticeable hesitation I had, is GONE.
Better for me and certainly better for my engine.
So.... just wanted to share a successful conclusion to a nagging problem I have had with the car and also to provide a tried and proven resoucre to our community.
Regards,
Ken Bigham www.jdsporsche.com
I have been trying to isolate a hesitation issue for the last year.
The car is a model year 85. New coils, wire set, caps, rotors and plugs all as a point of general maintenance did little to improve the hesitation in the upper RPM range just as the engine came "on the cams". I went to a rising rate fuel pressure regulator and this helped as I dialed up the fuel pressure. But I was unable to get the hesitation completely out of the vehicle. I have an ARM air/fuel ratio gauge and the engine never appeared lean, but that was the consistent feel I had while pushing.
For reference I Have an Authority Chip set, custom 3 inch insulated intake runners, modified air box ( I have smoothed the walls and built a radius in the floor of the box to help the air turn into the throat of the MAF) , stock manifolds wrapped with header wrap, gutted cats and a 3 inch exhaust. The exhaust is also wrapped from the manifolds to the exhaust tip.
No air pump, No AC, belt fan replaced with an electric.
In an exchange of e-mails with John Speake, he was extremely helpful in
providing valuable information which led me to the conclusion that the MAF had finally given up the ghost. According to John a 2% error in the Maf can cause a 10% lean issue with the engine. My raising the fuel pressure with the Rising Rate Regulator was just helping to compensate for the out of calibration MAF. John provides a recalibrated exchange for $450 with a $100 core fee which is refunded upon return of your used MAF.
I ordered a MAF from John. The first thing I noticed was just an improvement in the off throttle driveability. I've had my 928 for 9 years. I think we lose perspective as some items slowly deteriorate. The car is now more of a pleasure to drive than it has been in several years. Throttle response is much improved and the noticeable hesitation I had, is GONE.
Better for me and certainly better for my engine.
So.... just wanted to share a successful conclusion to a nagging problem I have had with the car and also to provide a tried and proven resoucre to our community.
Regards,
Ken Bigham www.jdsporsche.com
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checkmate1996 (05-18-2021)
03-22-2004, 02:13 PM
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http://cgi.ebay.com/ebaymotors/ws/eB...tem=2468788484
No offence to John, but they are only 100-200 brand new.
No offence to John, but they are only 100-200 brand new.
03-22-2004, 02:43 PM
#3
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Old & New:
The above is certainly an option. While I am tight with the dollar, there was more value to my transaction than I would ever have garnered from an E-bay seller. John helped me sort through my diagnosis and provided an assurity that if his recommendation didn't help I could return the unit.
I've been known to pay a little more than I should for items on occassion, but it's usually when the seller has went out of his way point me in the right direction and taken time out of his day to make sure I am going to be satisfied with the product for my intended purpose.
As Ed Ruiz used to say YMMV. (Your mileage may vary)
Regards,
Ken
The above is certainly an option. While I am tight with the dollar, there was more value to my transaction than I would ever have garnered from an E-bay seller. John helped me sort through my diagnosis and provided an assurity that if his recommendation didn't help I could return the unit.
I've been known to pay a little more than I should for items on occassion, but it's usually when the seller has went out of his way point me in the right direction and taken time out of his day to make sure I am going to be satisfied with the product for my intended purpose.
As Ed Ruiz used to say YMMV. (Your mileage may vary)
Regards,
Ken
03-22-2004, 02:53 PM
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I have the greatest respect for John, but also want the 928 community to be aware of an occasional bargain. This sensor won't be available on eBay forever, and (I presume) this one item is only a small part of John's business.
03-22-2004, 06:40 PM
#6
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Old & New,
Thanks for the comments. I didn't realise that the EBay guy still had stock.......
MAF sales in the US were an important part of my business last year when these Ebay units became available. It was rather annoying, after I had made people aware of the whole business of MAF ageing, and its slow degradation of perfomance, just as Ed has stated.
My product line is growing, as well as MAF and ECU rebuilds, I can offer EPROM upgrades. Near completion are several other products which I will announce in the next few weeks.
Thanks for the comments. I didn't realise that the EBay guy still had stock.......
MAF sales in the US were an important part of my business last year when these Ebay units became available. It was rather annoying, after I had made people aware of the whole business of MAF ageing, and its slow degradation of perfomance, just as Ed has stated.
My product line is growing, as well as MAF and ECU rebuilds, I can offer EPROM upgrades. Near completion are several other products which I will announce in the next few weeks.
03-22-2004, 07:38 PM
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Yep I picked up one of those $75 MAF's off of e-bay since my vacations are short, my plan is to replace one MAF with new one send the used one to John and then rotate the MAF on the second shark. That will leave me with a spare MAF for trouble shooting and minimize my down time.
However the $75 MAFs are a thing of the past as I believe the guy on e-bay woke up and raised his prices.
However the $75 MAFs are a thing of the past as I believe the guy on e-bay woke up and raised his prices.