Engine

Fuel Injection Brain Info: '87/'88

The LH computer on my '87 automatic is intermittently failing and needs replacement (hard cold
start, intermittent rough idle...mechanic says computer is failing). I think the '87 part number is
928.618.123.10. Does anyone know if I can replace it with the '88 part, I think its number
928.618.123.11?

I'm wondering because the '87 and '88 vehicles are similar in so many respects, but the shop
manual says the LH computer on the '87 does not store ignition/injector system fault codes.
The '88 does store fault codes and they can be read with the diagnostic flashing code tester
9268. I happen to have the flashing code tester and I'd like to be able to use it on my '87.

Any ideas on the subject would be greatly appreciated.

Al Reichert



I too have an '87 and am trying to troubleshoot a persistant running rich problem/slightly rough
idle problem. I have tested/replaced every sensor and may have some kind of brain failure. I do
know that an '88 brain will work fine. I also have learned that the rebuilt brains for 87 and 88 are
the same...I like, you was/am also looking into this option if I have to replace mine. My guess
is that the rebuilt is basically an '88 (with all the fault testing features). Where did you manage
to get hold of the 9268? And also, have you tested the 9268 with the '87 brains?...I know that the
tester connection is there (mounted on the side of the control units) and wired up...

Thanks and curious,

-Ed Y.
'87 S4