Hi all,

Been a long time since I have posted but, I am trying to get my Z running and having a fairly serious issue with it.

I had the motor re-balanced, thanks to my local engine shop for finding the $400 spec Stage III+ clutch to be out of balance by 28 grams .
After getting the motor back in the car and running, regardless of open or closed loop condition I have TTSDatamaster showing me that the LTerm & STerm counts to be in the 130's. I didn't notice what the MAF was doing, yet, but will this afternoon. It also feels like there is some detonation going on at idle, too.
With that said do my O2 counts seem to say i'm rich or lean? I am wondering if I have a injector stuck open and plan on taking them off and have my wife crank the motor for me this afternoon to see what it does.

btw, the MSD OPTI was sent in and checked while the motor was out and I have to ohm out the MSD 8.5mm on the passengers side today also.
any other suggestions?
Thanks!

 

You're not detonating at idle, it's just running rough. Your pcm is adding fuel because it thinks mixture is lean. I would start by looking for exhaust leaks possibly throwing off the O2 sensors or vacuum leaks or leaky intake bellows. Don't forget to check the intake manifold for vacuum leaks.

 

Thanks I will look for leaks. I looked the plug wires over three times for that detonation/mis-fire that I'm feeling. It actually feels like a misfire and the idle bumps/hic-ups every time i feel it.

Anyone know what the MAF (AFGS) should be reading at idle?

 

Running at the correct A/F ratio, your LT's would be 128. If you are in the low 130's, you are within the normal tolerance of the system. Anything under 135 is not unreasonable. That would be less than a 5% correction.

I doubt your ST's are always in the 130's. If they were, the PCM would keep increasing the LT's until the ST's switched back and forth on either side of 128.

Post the data log on an FTP site, so people can take a look and help you out.

If you had "detonation", your data log would be showing knock retard. Is it?

For "normal" readings, check this out:

http://www.injuneer.com/ScanMast.html

At the correct idle speed, you should be seeing MAF flow in the range of 6 - 10 grams/sec

 

Alright I had to pull the opti, get a stud puller and bring the cam dowel pin out 5/16" so that it engaged with the Opti. I think the engine builder may have backed it in when it was getting re-balanced.

Started up and it ran rich in open & closed loop. Fuel is at 44 PSI not running, I won't have the fuel pressure reading running till tomorrow.
How do I get to the ftp site?

 

Datamaster file

http://cid-258130334c04264e.office.l...master%20Scans

 

I downloaded it. I'll take a closer look at it tomorrow. Speed indicates 0 MPH in all frames. Is your speedo not working?

There's some sort of problem - its only running in cells 16, 17, 18 (may be the result of no VSS signal). Appears its pulling out a lot of fuel, with very low long term fuel corrections. LT's are down as low as 110. That is not consistant with your initial post which indicates the LT's and the ST's are in the 130's.

 

The car was on stands when I took the data log file last night. I will have it on the ground tonight to log the car under load.
The original condition was due to the Cam "dowel" pin not being out far enough to hook the opti-spark. Tearing the front end back off the car and using a stud puller I was able to get it out to go into the opti-spark.
Now I have a the actual "Rich" condition, I layed awake last night thinking that the only real variable that has changed since Dan @ FLP tuned it was the MSD opti that has adjustable timing on it? If I am too rich or to lean through the entire rpm range is it possible that my timing is off? Did you notice on the (no load) idle file that I am pulling timing out, even at idle?
Holding the RPM at 4K there is a miss that you can hear too.
What is do you think?