Sanity check please

[Forcefedperformance]

Just a sanity check befor we start to dive in to the motor, Car is a 02 Z06 416 LS3 9.1 comp,6.0 truck heads, small cam, Kooks 1 7/8, P1-SC... We are having a problem with the ignition wanting to to break up(we think) at 5,000 rpm, allways at 5,000. We have changed the blower pully so we are only making 3psi so its not boost related, we pulled timing ,added timing,changed spark plugs( TR6 With .035 gap) changed coils, changed the CPS. So now we are at the point of thinking its something with the file or its something with the motor. If some could please look over the file and just make sure that we are not over looking something.

Thanks Bill

[Chalky]

Big Red X! Can't see or download files!

[Forcefedperformance]

Click On the name of the file to download

[WeathermanShawn]

Are you sure the MAF is failed?

I don't see a DTC? Realize this is a COS..but do not see a MAF DTC in your log.

Not sure it would fail with P0101-P0103 set to 'No MIL' and Processing Enablers set to Non-Emissions (could be wrong).

That is all I can see. If this does not apply to your COS and your application..please forgive me. But, if you wanted a sanity check..that would be my input..

Good luck..

[Forcefedperformance]

Are you sure the MAF is failed?

I don't see a DTC? Realize this is a COS..but do not see a MAF DTC in your log.

Not sure it would fail with P0101-P0103 set to 'No MIL' and Processing Enablers set to Non-Emissions (could be wrong).

That is all I can see. If this does not apply to your COS and your application..please forgive me. But, if you wanted a sanity check..that would be my input..

Good luck..

Yea the maf is falied for sure...If you look at the custom os 2/3 bar tutorial on page 15 the settings match.


If you look at the data log and click on the obd2 tab (F7) then click on the red engine symbol you will see the p0102 code with the codes for the front wheel speed sensors because of the dyno.

Thanks for taking the time to take check it out shawn, just wanted a second set of eyes so i did not think i was losing my mind

[WeathermanShawn]

O.K. Got you.

Thanks for the explanation. I will bookmark that answer, as it is one of the better explanations concerning detecting DTC's with a COS/Dyno etc.

I agree the rest of the tune passes any sanity check I can ascertain. Do you think it is mechanical then?

Good luck..

[joecar]

Bill,

I see the MAF DTC in the log file.

In the log I see the rpm progress up thru 5000 without anything looking wrong or like its stumbling... does the dyno show a drop in power...?

In the tun file the limiters are all set higher than 5000 (other than the cold limiter but the engine is past being cold)...
I didn't see anything that might be wrong elsewhere (VE, OLFA, PE, spark/dwell, IFR)... I see it setup for OLSD.
BTW: I see the PE Delay Counter B3609 is set to 1.0s in all cells.

What does the wideband say when this happens...?

What valvetrain components are being used...?

[Forcefedperformance]

Bill,

I see the MAF DTC in the log file.

In the log I see the rpm progress up thru 5000 without anything looking wrong or like its stumbling... does the dyno show a drop in power...?

In the tun file the limiters are all set higher than 5000 (other than the cold limiter but the engine is past being cold)...
I didn't see anything that might be wrong elsewhere (VE, OLFA, PE, spark/dwell, IFR)... I see it setup for OLSD.
BTW: I see the PE Delay Counter B3609 is set to 1.0s in all cells.

What does the wideband say when this happens...?

What valvetrain components are being used...?

Rockers are stock,Patroit duel springs, 6.0 patroit heads,Comp push rods, 230ish/240ish cam. Did a compression and leak down and it was fine.

Dyno shows a Very small dip at 5100, A/F is 11.8 one when i stayed in it a bit it shows lean like the spark is geting blown

UPDATE:
We make a pull with blower disconnected and pulled it all the way to 6500 with no problems, but when we put it back on it does not matter if its 3 psi at 5000-5300 or 7psi at 5000-5300 its always at that rpm with the blower. Also it sounds and acts more like the spark is getting blown out rather than a rev limiter

Also dont know if it relvent but on the last pull i was looking over the data log and i seen that the throttle position stays at 99.6 ( like normal ) but right at 5100 it goes to 100 for one frame

[joecar]

Spark blowing out sounds plausible... that maybe supported by seeing it go lean (fuel stops being burnt causing excess oxygen)... but are you sure...? I see the boost VE table has a valley at 125 kPa (3.5 psi boost) from 4000 rpm and up, could that be a possible cause (eliminate that before gapping the plugs)...?


It seems to me that TP at 99.6% vs 100% would not make any difference.