Yeah, poor idle and lack of responsiveness (wanting to die rather than rev) usually means the air/fuel equation is off, so either a vacuum leak past the MAF or too weak fuel charge - seems like 95% of the time it's air getting in past the MAF

 

Sorry i haven't responded im on vacation and haven't been online much. I should be getting my car back mon or tues, i'm going to trailer it back to Lake Placid. My car was running fine after i did the AC work so I don't belive i disturbed anything by doing the AC. The fuel should be good i just filled it up on on mobil 1 which seems to be a good brand name gas.

 

Dennis, where are the .4 and .6 ohm resistors? I'd like to check those when i get my car back.

also i dont believe my model year (cis) has an maf.

The mechanic who was helping me with the AC work used to work for porsche back in the early 70s, before the 928, he seemed to think that the warm up regulator might be the issue, any thoughts? Apparently those were sources of problems when he worked for porsche

 

Kyle,

The resistors are on a panel in front of the left wheel well. Follow the wires from the 15 post on the coil.

The cis system has an air sensor plate rather than a MAF but they both measure air flow.

Haven't seen a WUR go out and cause a nonstart. Typically they start running rich or lean. Also, if the WUR was bad, it would still start on the fuel from the cold start valve, then die.

Dennis

 

Sorry if i was misleading but my car will start, although it takes quite a few tries. Once started it has an extremely rough idle and wont rev at all, after a while it usually dies. Also, a few days before my car would rev up to 4000, then slowly creep up the rest of the rpms with a lot of popping like it was running lean.

 

Ok, my uncle came over and was looking and we found the problem to be the vacuum lines. So we started replacing the vacuum lines. During the process as i was prying a line of a plastic connector attached to the front of the intake manifold, the plastic piece broke, the PO had way overtightened a clamp on the line and had cracked the fitting causing a leak. Now i need to find that part, any idea what a part number on it is or where to buy, i cant find anything on it. BTW my uncle held his finger over the broke fitting and the car idled fine.

 

I believe the part is front center plenum vacuum port but i cant find it anywhere.

 

Is it just a black plastic piece that looks like a T? You can pick up white ones at the Auto Parts store in the "Help!" packages for a few bits.

 

No, it attaches directly to the intake manifold via two allen bolts. Its not a generic part its definetly only for a 928.

 

Ah, that's right, yours is different from mine. Put in a call or email to Roger Tyson at 928sRus. He should be able to find what you need. www.928srus.com

 

I've emailed roger, but its was friday night so i'm not sure ill get a response for a few days. I'll see if i can get on another computer later and see if it allows me to post pics.

 

If it is on the upper plenum and the tube bends toward the passenger side, that is the vacuum port for the A/T solenoid. On the 5 speeds it is normally blocked off.

Dennis

 

Where was your uncle when I couldn't get my 79 running?

 

Well, i went thorugh and replaced all the vacuum lines i could find and the plastic cold start valve mount that was cracked, and the cars still running the same, barely idles and runs rough at idle wont rev at all

 

Still sounds like an improper air/fuel mix - I'd guess either you've got extra air coming from somewhere (like rubber intake boots) or the computer isn't able to determine how much air there is for some other reason (disconnected, or bad MAF)