gsmarrara

No, i'm using a gas called podium, for imported cars with compression ratio over 10:1. Its 93 octanes but have up to 20% of alcohol, what will destroy the fuel hoses very quickly. The only problem is the price at us$ 7 dollars per gallon. I have to use the same gasoline in my merc c63...the car works very well...not so good for my pocket

gsmarrara

By the way, anyone knows if the knock sensors for 928 is similar to the ones found on audi a4 and a6.? My mechanic told me they look very similar....and would be easier to find locally...any bosch part number for them? Thanks

Hilton

Same part IIRC - a search through the old rennlist posts should bring up the numbers you want.

James Bailey

from ebay add....."2 Audi Quattro 90 A4 Porsche 928 VW Jetta Ignition Knock (Detonation) Sensor"
THEY think it is the same....

worf928

The foil is RMI shielding for the Hall, Knock and RPM/TDC/CPS sensor. And yes, if the shielding is compromised electrical noise from the ignition system can cause problems. That shielding is connected to ground via the LH's pins.

gsmarrara

Hi guys,thanks for the help. Actually, the experience of ownership of a 928 without this forum would be a real nightmare. Well, not good news. As I reported the knock sensors lost the shielding and the connectors falled apart in my hands. But the worst is that the hall sensor was simply disconnected at all. After the replies I chased the hall sensor (that I made confusion with the CPS at first), and was not connected to anything. Them, after a lot of tracing, found the unused harness to hall connector hidden under the passenger side fuel rail covers. When I tried to connect both, of course, the connector simply disappear in my hands. So, now I will replace the hall sensor, and as I will remove the intake for the knock sensor, will replace the CPS tool and check/replace the vacuum hoses, using original/bosch parts. So parts importation process starts (45 to 60 days), and will get back to give a feedback to you guys by them, once every single new part is connected. The car will be in the garage by them. Yesterday, after messing a lot with the car to solve this issue, a heavy misfire started (but dont seem to be running of 4 cilinders), maybe ground problems or a loose injector plug, so will keep the car parked and solve everything at once when I receive the parts. Best regards and thanks for the help. Happy easter. GM.

Mongo

Gsmarra, I saw the reply about the shielding, but wanted to make sure the wiring on the harness side, not the knock sensor itself, still had its shielding I had a knock sensor harness disintegrate on me too, but was successful at repairing the wiring harness and shielding too with a thin type of aluminum foil (not your typical Reynolds Wrap in grocery stores), followed with shrink tubing and electrical tape. The repair still kept the noise away from the sensors and the car feels like its true self after stepping out of the dealership in 1987.

I would only recommend doing this if the knock sensor wiring harness has fallen apart on you. Also, if you're having ground issues, check the LH and EZK grounds at the back of the motor, under the airbox and next to the fuel pressure regulator and dampener.

Happy Easter

gsmarrara

Hey guys, reporting back on this as well. Made several checks and now my car is running as it should...by the way, NOW i know how a 928 should drive, 4000 to 6000 rpm is amazing!!! Well, replaced the 2 knock sensors, and "fixed" the hall sensor (just connected properly until the new sensor arrives, but the current one is still working). More important, just discovered 2 of my ignition wires were compromised and under load they fail. Will order new ones (Beru or Magnecor) today, and the shop borrowed new wires until the new set arrives. Fuel pressure is ok (3.0 at idle) and the performance is good now. Tried to replace the MAF, but the new unit I bought didn't work (was a brand new unit from a M5, that should be the same, but it's not! Smaller diameter). So, just cleaned the MAF and seems to be working ok now. No misfire, good performance. I never drove another 928, to have any reference, but the car is quite strong. Just one thing to be solved now: just one of the fans is working most of the time, the driver side. The other one, sometimes works, sometime not...but when it works, the other one doesnt...so...only one of the fans work at a time, and i cant see a patern why one or the other kicks in. Both should always work at the same speed, right? Could it be the fan final stage? Where is located on OB's? Thanks and best, GM

Randy V

Try breaking your posts up into multiple paragraphs - makes it much easier for us to read.

James Bailey

Could it be the fan final stage? Where is located on OB's? Thanks and best, GM

The early cars do not have a fan controller...your car is triggered normally by a temp sensor in the radiator in the end tank left side in front down low. It comes on at about 3/4 on most temp gauges. That may be what they wired in for your second fan. The fan which runs all the time is probably hard wired to run when the engine is on. But I can only guess as your car is not original....

gsmarrara

Hi James, thanks for the reply. But let me clarify that the driver side fan is not always on...it turns on when the gauge in around a little over the middle of the scale, and shut down normally a minute or so after that. The passenger side fan almost never kicks in...but when it kicks is, the driver side stops. So, only one working at a time. Anyway, is not really a major problem, as the car never overheats and never reached the 3/4 in the gauge scale.

Anyway, really enjoying the car now...a little scary when the tach reaches 6400...but really fun!
Best, and thanks, GM.

James Bailey

Great you have it running well !! these cars are so much fun. Such a difference from the Maverick experience...

gsmarrara

Totally!!!!!! Maverick is also very fun...but for slow cruising or quarter miles in straight line with a lot of space to brake....Porsche, well, its fun while you are slow, or fast, straight line, even more in the track full of twists. I compare the Porsche with my Mercedes year 12/13, and while the Maverick drives as a old car (even being totally restored until the last screw...google "ford maverick" and the black one with silver stripes is the first one in the search result is mine one), while the Porsche feels modern...feels like a car that could be leaving the factory today, after 31 years!!!! amazing engineering!