It all started with pinging. The ping was caused by the timing being way too far advanced. It was hiding the real problem: lack of power. Adjusting the throttle linkage correctly has helped a little, but the engine is still dragging. Today, my mechanic put a test pipe in place of the cat, and it made no difference. I've an appointment to leave the car off with them on Tuesday for a more exhaustive battery of tests to try and track down the problem. Wish my car luck

 

Let's hope it is something as simple (and low $$) as a bad 02 sensor!

 

Hmmmmmm,

So the timing was off... How did it get that way..? If the car is detonating from the timing being advanced, was it set there intentionally..? Did you get a bad batch of gas recently...? (could cause the knock)

How would the throttle cable help with the detonation...? The TPS has only idle, MAP, and WOT..? Are the cats a known failure..? When was the last time the car was smogged..? What has been done since then to it..?

I smell fish...

But, wish your shark good luck anyway...

 

The ping was happening over several tanks, from different stations. I basically drove the car very conservatively for a while during this time. Its getting the same gas it used it. I can't say with certainty when the pinging started, so I don't know when the timing got off. Several difference shops have been into this car, so any one of them may have played with the timing. Once the timing was set to spec, the pinging stopped. But, the car was way down on power.

Slop in the throttle cable was preventing proper WOT, thus giving the impression of there being less power than there should be with the peddle all the way down. I think the throttle adjustment was its own issue, and has nothing to do directly with the pinging or the current power issue.

The problem now is that even after setting up the throttle and timing correctly, the car is lacking some oomph.

 

Maybe your O2 is out, or your injectors need a good cleaning.. Also the fuel filters.....

Oh, if you ever ran the fuel down low, some dirt can clog the fuel filter and seem to make the car struggle...

If it's now reset to baseline, I'd have them look at little things first that you know if changed could affect the oomph..

When was the last time you changed the filters, and cleaned the injectors..?

Throw in a bit of redline SI-1 or Techron on a half tank and add a bit to mix... Run it a bit then fill some more gas...

Is the oomph in the low end..? mid..? or high end of the rpm scale...?

 

Its definately missing something on the low/mid end. I'd have to drive it a bit more to get a better sense of the high end.

I have not recently done any filter change or cleanings. I've got a bottle of STP injector cleaner at home that I can add in today.

 

Maybe it's time to change filters and see what happens... They do get clogged you know... Kind of like clean vs dirty water for people... What do you drink..?

 

Me? I prefer a nice a merlot. But, the owner's manual clearly states the one should not run alcohol-based fuel additives in a 928 for a prolonged time

Point taken.

 

Jessa,

May also have your mechanic check the cam timing. Any jump would also affect the ignition timing.

Dennis

 

Jessa,
Merlot? What ever happened to a nice Blush, or, a Rose Sec.
As to your baby...
Slip on over to Greg Nichols site.
Go to engine then pinging.
There are a few things there that were not mentioned yet,
like; vacuum, crank sensor, knock sensors - if you are so equipped - the diagnostic description really matches up with your post. Give it a shot and maybe hang on to a few bucks...
Good luck.
P.S.
Is your Weissach gone? Where to?

 

Have you given it a good Italian tune-up?

I'm out of my league on the earlier L-Jet cars, but we should have plenty of people to analyze the anemia this weekend.

 

Italian tune up??

 

Ya know, clean out the cob-webs, crack the whip... Drive the hell out of it

 

Yeah, what BJ said, to blow out carbon and unstick lifters.

 

John, after a surprizingly smooth eBay transaction, the Weissach moved to its new home in Sacramento. From the few minutes I spent chatting and going over details with him, I think the new owner will take good care of it. I haven't heard from him or seen the car since, but a friend did spot it on the freeway near Sac about a month ago.

Bill, only briefly. We just got it to stop pinging under load. I'll try and drive the snot out of it a little more