Resistor in parallel to temp sensor II to change air-fuel mixture?
08-25-2003, 10:45 AM
#16
Rennlist Member
Normy,
Sounds like running weak if you get a bang on overrun.............
Open another thread, or PM me so we don't get in the way of Thomas' thread...
Regards
Sounds like running weak if you get a bang on overrun.............
Open another thread, or PM me so we don't get in the way of Thomas' thread...
Regards
08-25-2003, 12:24 PM
#17
Advanced
Thread Starter
Hi John and other people who are interested
I guess I finally have the solution of the story: the fuel pressure @ 700 rpm was 3.7 bar (instead of 2 bar)! And the explanation (by an elder Porsche mechanic from AMAG Safenwil, the Porsche importer for Switzerland) is the following:
These cars (928 S2 imported to Switzerland) had a problem with hesitation (lean condition) even when they were new because of the then newly changed strict emission laws in Switzerland. They even stopped importing S2 manuals after 1984 and just imported autos, because the lean condition was less noticeable.
He told me that the solution was to press the fuel pressure regulator together (increase the spring load against the vacuum) to increase the fuel pressure to about 2.5 bar. Probably when my car developed a problem with a lean MAF somebody pressed the fuel regulators together even more.
I ordered new fuel pressure regulators today and hope this will finally make it perfect (I hope I will not start the hesitation problem all over with new pressure regulators).
BTW John: Just in case the car will not run so well with the new pressure regulators: what does it take to make the Swiss ignition ECU the same as e.g. the English one? Just a different EPROM? could you sell me one?
Cheers Thomas
I guess I finally have the solution of the story: the fuel pressure @ 700 rpm was 3.7 bar (instead of 2 bar)! And the explanation (by an elder Porsche mechanic from AMAG Safenwil, the Porsche importer for Switzerland) is the following:
These cars (928 S2 imported to Switzerland) had a problem with hesitation (lean condition) even when they were new because of the then newly changed strict emission laws in Switzerland. They even stopped importing S2 manuals after 1984 and just imported autos, because the lean condition was less noticeable.
He told me that the solution was to press the fuel pressure regulator together (increase the spring load against the vacuum) to increase the fuel pressure to about 2.5 bar. Probably when my car developed a problem with a lean MAF somebody pressed the fuel regulators together even more.
I ordered new fuel pressure regulators today and hope this will finally make it perfect (I hope I will not start the hesitation problem all over with new pressure regulators).
BTW John: Just in case the car will not run so well with the new pressure regulators: what does it take to make the Swiss ignition ECU the same as e.g. the English one? Just a different EPROM? could you sell me one?
Cheers Thomas
08-25-2003, 02:13 PM
#18
Rennlist Member
Hi Thomas,
Glad the cause of the problem has been identified !
The EPROM in the LH2.3 EZK is a really old type, which I can't copy yet. The later LH 2.3 EZK is no problem.
I think the EPROM would be the only difference bewtween Swiss and ROW S/S2 cars.
Glad the cause of the problem has been identified !
The EPROM in the LH2.3 EZK is a really old type, which I can't copy yet. The later LH 2.3 EZK is no problem.
I think the EPROM would be the only difference bewtween Swiss and ROW S/S2 cars.
