928 S4 engine shuts off while driving.
04-08-2019, 01:58 PM
#16
Chronic Tool Dropper
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Maybe some basics need to be reintroduced to the discussion.
-- There's an annual electrical maintenance protocol that includes cleaning all the ground points. Failure to follow this protocol can lead to a slew of odd running issues.
-- Ground strap on the engine and on the battery need to be replaced if they are original. "They look OK" is not an argument against "need to be replaced"; Just Do It.
-- CPS replacement isn't something that happens "regularly" but is certainly part of a good intake manifold refresh. Usually the wire and connector give out before the sensor itself fails. You can look at the connector and wiring by lifting the airbox for access. The sensors aren't expensive but access is not convenient. Oh wait... You have that stuff off to clean the ground points on the top rear of the engine, part of that annual electrical maintenance protocol. Look, see, replace CPS as needed.
-- By this time, every LHA box on S4+ cars should have been replaced. Rebuilt units from any of our favorite rebuilders (John Speake via Roger and Louis Ott, 928 International, Rich Andrade at Electronik Repair in Phoenix) should not be a normal concern. Replacing your old unit with another working old unit is no better than replacing one ticking time bomb with another. You still don't know when the ticking will stop. If you still have the original controller in the car, swap it now for a rebuilt unit. Few owners are lucky enough to have theirs fail with the car sitting in the garage.
-- Relay-relay-relay is a similar prophylactic effort. Replace the relays before they strand you. Buy a couple ride-along spares too, and never worry about needing them. It's like keeping a St. Christopher medal in the car, but for the relays. Throw The Old Ones Away.
----
Wally Plumley's "Annual Electrical Maintenance" document is/was available for download at the 928 Specialist website www.928GT.com Performing that work annually dramatically reduces so many common electrical symptoms that not following it should be grounds (sorry...) for disbarment from the 928 DIY fellowship. Electrical irregularities seem to be the major Achilles Heel in so many ownership experiences. The opportunity to take care of so many possible issues with an hour or two of work seems like a no-brainer to me.
After you've done all that stuff, only then should one come to the well of knowledge and experience for additional guidance, grasshopper.
In my opinion anyway.
-- There's an annual electrical maintenance protocol that includes cleaning all the ground points. Failure to follow this protocol can lead to a slew of odd running issues.
-- Ground strap on the engine and on the battery need to be replaced if they are original. "They look OK" is not an argument against "need to be replaced"; Just Do It.
-- CPS replacement isn't something that happens "regularly" but is certainly part of a good intake manifold refresh. Usually the wire and connector give out before the sensor itself fails. You can look at the connector and wiring by lifting the airbox for access. The sensors aren't expensive but access is not convenient. Oh wait... You have that stuff off to clean the ground points on the top rear of the engine, part of that annual electrical maintenance protocol. Look, see, replace CPS as needed.
-- By this time, every LHA box on S4+ cars should have been replaced. Rebuilt units from any of our favorite rebuilders (John Speake via Roger and Louis Ott, 928 International, Rich Andrade at Electronik Repair in Phoenix) should not be a normal concern. Replacing your old unit with another working old unit is no better than replacing one ticking time bomb with another. You still don't know when the ticking will stop. If you still have the original controller in the car, swap it now for a rebuilt unit. Few owners are lucky enough to have theirs fail with the car sitting in the garage.
-- Relay-relay-relay is a similar prophylactic effort. Replace the relays before they strand you. Buy a couple ride-along spares too, and never worry about needing them. It's like keeping a St. Christopher medal in the car, but for the relays. Throw The Old Ones Away.
----
Wally Plumley's "Annual Electrical Maintenance" document is/was available for download at the 928 Specialist website www.928GT.com Performing that work annually dramatically reduces so many common electrical symptoms that not following it should be grounds (sorry...) for disbarment from the 928 DIY fellowship. Electrical irregularities seem to be the major Achilles Heel in so many ownership experiences. The opportunity to take care of so many possible issues with an hour or two of work seems like a no-brainer to me.
After you've done all that stuff, only then should one come to the well of knowledge and experience for additional guidance, grasshopper.
In my opinion anyway.
04-08-2019, 06:18 PM
#17
Chronic Tool Dropper
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I just looked at the 928 Specialist website, and unfortunately Wally's annual electrical maintenance doc is no longer available. I have a copy but need to get the OK from Wally before I add it to the thread.
04-08-2019, 06:32 PM
#18
Chronic Tool Dropper
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"OK to share" graciously given by WallyP. Meanwhile, I found a copy hosted on Greg Nichols' tips site at http://www.nichols.nu/tip725.htm
Last edited by dr bob; 04-09-2019 at 12:49 AM. Reason: added Wally's permission statement.
04-09-2019, 11:40 PM
#21
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How many miles on this 928?
What does the LH engine harness look like? Any history of issues or repairs on it?
