Ed Scherer

I wasn't thinking about directionality as much as distance from the filter to the mouth of the MAF. Putting it in upside down (bulgy side down) puts the lower surface of the filter pretty close to the MAF and probably means that a more air has to be pulled sideways across the filter rather than straight through the filter. I'll bet there's a measurable (but probably small) difference.

More importantly, it really doesn't fit quite right upside down. Furthermore, IIRC, the filter materials themselves are not symmetrical; I don't think it was a symmetrical sandwich.

Tom928

Another thing that looks to be common are the tabs on the sides.
Regradless of the arrows, the side tabs extend away or down when the curved part faces up.
Easy way to tell which way the filter is in without taking it out.

Cheers,

Ed Scherer

It's been almost a week since (in post #144, after replacing the EZK/LH EPROMs with SharkTuner PEMs and replacing the fuel pump relay) I said:

Well, it's been consistent. Consistently good, luckily. Not a single bad episode. I've probably driven the car twenty times or so over this time period.

My best guess (too bad I changed multiple things at once!) at this point is that:

• replacing the fuel pump relay probably didn't fix the problem;
• having PEMs (instead of the original EPROMs) in the EZK/LH brains probably didn't fix the problem; but
• more likely — since in the process of replacing the EPROMs in the EZK/LH brains, I reseated connectors, flexed cables, flexed the PCBs in the EZK/LH brains, etc. — an intermittent bad electrical connection somewhere has probably been fixed (at least for now ).

It's unfortunate that I don't know exactly what was going wrong before, but I guess at this point, I'll just count my blessings and see how things go.

I've got confidence in the car again (I don't worry about it stalling at intersections, etc.) and am enjoying driving it in the nice, cool, autumn air.

John Speake

Fingers crossed :-)

tylenol

Well sh** I was hoping you would find something. My symptoms are almost identical. Im glad for you though!! Aaron at KCporsche has been working on mine off and on for a month trying to figure out the stalling. Good luck and I will post what he finds and all my symptoms if and when it is fixed.

LGL

With similar symptoms, I just discovered that disconnecting my MAF makes stall go away. I haven't figured out why yet.

Ed Scherer

FWIW, yet another week (more, actually) has gone by and my car is still running just great.

I don't think I'll post any more reports unless it reverts to its weird behavior.

Thanks again to everyone who offered assistance at various times during all the work I did (most of which was referenced in this thread) on my car this summer.

The Rennlist 928 Forum and all the people who gather here to help one another are the best!

John Speake

Ed, that's good news :-) Are you still running with the PEMs ? The ST2 software is based on the MY88 software, I think this is better is some respects than that fitted to 90 and later.

Ed Scherer

Yeah, the "bendy tabs" on the metal LH cover don't exactly promote getting into the LH frequently, do they?

John Speake

Duck tape makes a good temporary fix for the lid.....