944 S brain damage
 

This is a follow up on my past post ..."attention all 944 gurus."..where after replacing the clutch and crank positioning sensor, the car failed to run...so here is the deal...I need a brain...DME for a 1988 944S 16 Valve

After an exhaustive diagnosis of the fuel and electrical systems and exploritory surgery on the existing (DME)brain...it appears that over time the curcuit on the DME that controls multiple items including the fuel injectors, fuel pump relay, and fuel pressure has overheated causing the solder to fail open. Why? dont know...no signs of shorts or opens or failing components including all relays, pumps injectors..(all bench tested) all wiring checked for continuity but to no avail... I simply do not get the injectors to fire...( note: with a spray of starter fluid in the intake, the engine will idle smooth for the duration of the spray. Without the spray you occationally get a sputter or really rough idle...so pretty sure it is a fuel issue)

We attempted to repair the connection on the DME board but no, it did not correct the problem...now we suspect that tne DME is toast....

The next problem is finding a DME for a 944S . yes the S is different as many of you know. the scary part is talking to parts houses that say it is not anyway...

I would like to try a known fucntional DME in the car to verify the problem is with the DME. But I am sensitive to using a loaner to determine the final diagnosis as I can not 100% gaurantee that the car will not fry another DME? On-the- otherhand, is there anyone with a 944 S that would agree to test my existing DME to see if thiers will function with it...either way we will come to the same conclusion...

Finally, if the problem is the DME, I would really like to score a used one for a "reasonable sum"...the car is nice but is apperently based on some of the prices of used units, is worth more in parts..

Any local 944 parts hoarder out there with a working "S" DME they are willing to part with? $$? Any 44S owners with a running 44 willing to experiment with my " abby normal" DME? again $$?

any other options? thanks guys for any additional feedback.

Scott 410-456-1955

I believe I already offered mine (2 monts ago) to be used as a known good unit.
Problem is I don't plan on being in your neck of the woods anytime soon. If my scedule changes, and you havn't found a test unit, My offer still stands.
If you want just run a vac. line into the cabin and buy a case of carb cleaner, and spray your way down here. :) Might work.

Be sure to contact George B. at http://home.hvc.rr.com/nine44/index.htm he has everything 944 and is also a good tech source.

UPDATE: New DME installed along with a new fuel pressure regulator...success...runs perfect...the curcuit controlling fuel injectors physically failed...the injectors simply did not "fire". still not sure why the curcuit failed. we suspect the fuel pressure regulator played a role.

With the Old DME out and disected you can see slight burnt area and an open in the solder on the board...fingers crossed that this will be a long term fix...

thanks for the help, offers and suggestions.


Scott