Bill Ball

There's nothing other than the jump post cover on the passenger side near the coils, and I can't recall seeing anything else there on other cars. The only other trim pieces I have are forward of the radiator and are there to help prevent the air coming into the nose from escaping from the radiator area. I can't find anything else in PET except "gasket lateral" shown below. PET appears to indicate 2 pair for 88 and before, 1 pair for 89 on. Anyway, that's my interpretation. Are these it?

Randy V

My car has these on both sides. I call them weatherstripping rather than trim pieces.

Trim indicates a cosmetic/aesthetic use. These are there to keep water from entering the engine compartment, so they are not cosmetic.

Bill Ball

Yes, I have those but they are nowhere near the coils. And my guess is they are there to seal off the nose air. Regardless if that's what Wally means, OK, I have them , but I can't see how they keep water off the coils. If anything, they would channel it up fender lip closer to the coils. I was interpreting his comment as indicating something above the coils. From my last pic of the left side coil, you can see it is pretty exposed.

worf928

Let's be precise: The ignition monitoring system is triggered by a difference in cylinder temperatures across the block. It's purpose is to detect ignition problems, but in practice anything that can result in a cylinder not firing well can trigger the IMS. So, besides ignition problems, the IMS can trigger because of a faulty injector, super-bad carbon buildup, a combination of component failures, etc.

Try a bad o2 sensor an out-of-spec MAS and a couple of dirty injectors and see what happens...

928 at last

Do as Wally said. Now you've gone to the coils, by all means clean up the connections, but if it's going into fault mode and running on four, you need to know. And, the lights are the easy way to tell.

928 at last

Lemme see.....car runs like crap and little red or green lights come on in a relay cleverly hidden under the carpeted passenger side footrest??? And if not corrected the driveshaft snaps??

Dwayne

Ahh....another mystery solved. Here's a pic of the seal/trim that Wally is speaking of just above the coil. Idaho, Virginia, and Oregon have them. I never understood what they were for (just above the coil) but now it makes sense. THANKS!

WallyP

I have been trying to think of a clearer way to describe these...

"It's a trim piece, (my terminology, not Porsche's), not a seal. Just a little clip-on piece of trim on the edge of the fender to deflect the rain/wash water where it normally spills off onto the coils. "

Perhaps, "The little black pieces on the right fender edge just above the coil in the bottom photo in post #37."

There should be one on each fender edge.

Bill Ball

Dwayne:

Aha! I can't say I ever noticed those on any other 928. You've got them on 3 out of 6. They must get knocked off rather easily as my car was previously owned by one of the most compulsive 928 owners I've ever met. - even more compulsive than you - but they were gone by the time I got the car. I'll pick some up at Sharktoberfest if i can figure out what PN they are.

Dictys

I had this problem, I traced it down to a distributor cap contact being worn.

It took a while to track down and by the time I had finished I had replaced the coils, rotor arms, plug leads, sparkplugs, distributor caps and added a fuel pressure gauge.

To cut a long story short, I ended up checking each plug on the side that the relay was telling me there was a temp difference, noted which clydinder was not firing by condition of the plug. Traced this back to the cap, looked at cap and replaced cap, sorted.

Bill Ball

My IMS used to trigger if I drove over a pothole. After it did it 2 days in a row at the same pothole on the way to work, I disabled it. That was 7 or 8 years ago.

Easy enough to check - pull back the carpet in the passenger footwell to expose the clear relay box and and start the car.

Rob Edwards

I have an IMS error on my GTS, kept tripping into 4 cylinder mode. Did all the testing and concluded that I have a dead sensor on one side or the other. But I can't reach them with the new headers in the way, so I have it jumpered.

Randy V

Anyone?

fonetico

Well, to conclude my brief episode, it seems that the world's in order again.
I've replaced the coil and HT lead and so far the engine is back on song.
I don't know whether it's my paranoia but I think I had a brief moment earlier where it felt as though it was stuck in second gear for a few minutes. I was navigating heavy traffic and it could just have been my imagination.
Will this be the next project? There's just no respite!
My first serious car was a 924 that I had for twenty years and ran up 300k on the clock. Apart from brakes and rubber, the only problem it ever had was a snapped clutch cable. Oh that the 928 were that reliable!

Randy V

Sorry, but the 924 is far from being a 'serious' car.