Jitters

Alright Gents,

Today while driving home from work I noticed a slight mis in the car. While observing the AFR meter, I noticed that when the car started missing the gauge would fall all the way down to 17 or in the red. The car normally operates at approximately 14.7 at idle and at normal cruising speed.

This is not the first time this situation has occured. About a month ago it did the same thing so I got pissed and parked the car. So about a week ago I went to start the car and it wouldn't crank. So needless to say I wasn't happy at all.

As I attempted to troubleshoot the cause of the car not starting, I stumble across what appears to be the intake tube (Hell, I don't know what the real name is) thingy that runs from the turbo to the side of the throttle body (Again, I don't know the freakin name). Well, anywho, the mechanic who installed the new turbo either didn't tighten the clamp or it just simple came loose. After re-installing the intake tube (You know what I mean) thingy. The car started So I drove the car around town yesterday for about 30 minutes or so and it ran fine. I drive to work this morning and it still running okay...It wasn't until I was on my way into Los Angeles this morning that it started missing again. HELP!

Can anyone shed some light as to what my problem might be?

Thanks in advance for help with this issue.


Jitters

Droops83

Well might be better off posting this in the 930 board, but a few questions anyway:
What year is your 930? Is it stock or modified? Is your A/F meter wideband? Missing under load, all RPMs, when?

As for the intake boot being loose, that would definitely be a problem; however, you state that the engine would not even crank. A giant vacuum leak on one of these cars will often cause it to crank but not start, since there is not enough vacuum to move the airflow sensor plate to get the fuel to flow. Is this what happened? If the starter does not even crank the engine, that is a different problem.

I'd check for more intermittent vacuum leaks like the one you had, IE when you boost a small leak opens up, etc. Check the intercooler/turbo O ring seals. Other than that I'd wanna know if you're an '86 and up O2 sensor car or not, and go from there, probably on the 930 board.

Jitters

Hey Chris,

Thanks for the feedback. The car is a lightly modified 1988. And yes, that was the problem. The sensor plate was unable to lift due to the lack of vacuum because of the intake boot being loose.

I'm pretty new to the PCAR world and a lot of the terminology is new to me but I'm learning. Not exactly sure what you mean by wide band AFR.

Also, I feel like boob...I've been posting here for a few weeks and did not realize that there was a section for the turbo's...I originally looked at the sections and saw air cooled then I went donw a little further to the water cooled section and that was as far as I got. So I assumed that the 911 air cooled section was all inclusive...Oh well, won't be the first time I made a gool of myself...

Well thanks again for the feedback and I'll see about posting in the right section next time...

Ciao,

Jitters