John Speake

What I heard was that the Holbert car was originally fitted with a very "pre-production type of EZK (i.e. with knock sensing) with the older type 25 way connector.

At some point this unit failed and 928 Intl (?) retro-fitted a standard later type EZK with the required 35way connector spliced into the car cableform.

Perhaps Mark can verify this ?

If correct, then it would be interesting to know the type number of the EZK box he has fitted (this can usually be seen withoutr taking the units out of the cradle) to verify if it is posy MY87 and in facty has diagnostics on that ECU.

mark kibort

Yes, i have the later S4 EZK and the LH box. I dont know for sure if it was a retro fit, or what. but there was a prototype box in the bag of stuff given to me with the car . the harnesses are new and came from 928 intl. the LH and EZK are new as well. Plus, there are the knock sensors plugged in.
I dont know off hand what year EZK, but Ill check. I think i have a post with pictures and part number when i sent the mystery box off to Rich A for investigation

mk

Jim R.

It would be interesting if the "original" boxes could be sent to John and looked at with the sharktuner to see what was programmed in there from the factory for fuel, timing, etc.

Back on topic, I would bet one of the knock sensors are throwing a fault code and pulling back some timing. If they are original, they are probably toast. Mine were both dead a few years ago, with 50,000 miles on an '89.

If so you really have 2 choices: deal with the power loss until you buy your new stroker motor, or replace them the right way by pulling the intake.

If $$$ is tight, you won't really hurt anything by leaving them non-op: just be down 20 hp or so.

Jim

heinrich

IIRC Mark has each bank showing compression consistently but the banks (rather, "sides") are out of sync. Does this not indicate a cam out of timing?

mark kibort

thats why i pulled the passenger side cover and did a measurement. it measured pretty close to spec, and having a change that seemed to make more hp at the dyno and on the track. (ie 2mm for both sides , vs 1.7mm and 2mm). It hasnt changed from that setting, although i didnt check the driver side, the pulleys are aligned to the timing mark and i have no reason to suspect that that side is not aligned to spec or has changed.

mk