DANdeMAN

In that case jump the pump with a wire (relay out of corse) and see what happens....

GregBBRD

It sounds like you could have a bad LH brain and the injectors are spraying all the time, flooding the engine. When you remove the fuel pump relay, the injectors would still be opening, but not spraying due to the lack of fuel pressure. Are the injectors clicking away when the key is in the "on" position?

James Bailey

Yes that does sound like the typical L H failure where it just clicks away dumping gas into the cylinders......once every 20 -30 years.

worf928

+3 on LH. Send it to one of the usual suspects for testing: Rich A., Louie "Dr.}{" Ott, etc.

hpracing

is this car auto or stick,i had some problems like you ,mine is 89 s4,my ezk was bad,had it repaired,still had problems trying to start,there is a relay for the auto kick down swicth for automatic,if you put a relay in that slot for a 5speed it will not start,check that out.....

Dean_Fuller

Mine is an Auto.


Okay...searched for LH rebuild and the threads are years old.

Who rebuilds these now days? How long is the turn around as I have been with out wheels for 2 weeks already.

risaac928

Can you guys post pictures of the "LH Brain" - and what woul it cost Dean for a new one? Are these hard to come by..

worf928

The same folks that did then in those years old threads.

Rich Andrade
http://www.electronikrepair.com/

Louis Ott
http://www.performance928.com/

Rich is a "rebuild service" and he rebuilds them in-house.

Louie has John Speak-rebuilt (JDS Porsche) units on-shelf for a "core exchange service"

Takes about a week.


See Rich's link.

1.207 bIllI0n dollars (as in... they are not available new and haven't been for some time)

IIRC used, broken one's that need rebuilding are ~$1000.

I think you can, at this point, make a good guess.

Note, that it is the LH 2.3 units (87-95) that are scarce. The 2.2's are easier to find.

CharlieL

Make sure both water temp connection are connected good.

Jerry Feather

Dean, If it is the LH, send it to Rich, the guy in post #9 in this thread.

Jerry Feather

Dean_Fuller

Can anyone lend me one so I can confirm its the LH? 1989 S4.

worf928

The correct approach is to put the suspect LH in a known-good car and see if it doesn't operate the known-good car. Send it to one of the rebuilders - they test them first.

Dean_Fuller

Okay...sent my LH off last week and heard back today. My LH is FINE! So back to square one.
This is what happens to update the thread...

Car will turn over but not crank. SOUNDS like no spark. I can SMELL fuel. Remove the fuel pump relay and the car STARTS evertime right away! Relay in...no start. All I know now I didn't know before is the LH is good.

SeanR

Yea, Sorry Dean, the LH fired up right quick in my car today. Wish I had some better answers. I'd guess ignition switch but we replaced it two years ago with a good Porsche one.

Landseer

Dean, when is the last time you had that CE panel out?
(Could there be wire melts behind it?)

There was a thread once about rear defroster button sticking in pod, causing backfeed voltage that somehow energized S4's to continue to run with key off. Wondering if that phenomena is somehow playing into this (realizing its not the symptom you are seeing, its the backfeed idea)

Last half baked thought involves shorting in the harness where it leads from back of valley and collects-up to pass thru firewall. You might try manipulating that harness with long pair of pliers to change the behavior. Or try metering every wire from cps, maf, etc, back to the proper terminal(s) on computer.

Not the answer you are looking for but something is misfeeding I think.