Log file lean for a split second

[Mike T]

Been tuning on the car and it was really coming around until I broke the forward drum......oh well.

Was chasing a little oddity in the log file when it broke. Notice that right after the black line in the screen shot the boost and rpm both drop and the A/F went to 12.5 for just a slit second and then straitened out again.

Any thoughts as to what it may have been. Only guess I have is maybe the pump was getting uncovered on acceleration.

 

[SCOOBY DOO]

NB drop out too? MAF drop out?

 

[Mike T]

Yes it did.

 

[TurboBob]

post the logfile if you can.

Bob

 

[Mike T]

I'll attach it tonight. Had just replace the coil pack and module to correct a misfire when this little glitch showed up. Believe it or not you could feel it nose over a bit. Thought it had to be pump sucking air so added 5 gallons of gas. Next log was inconclusive due to trans breaking.

 

[turbo nasty]

12.6 on volts is crap to tho

 

[Mike T]

12.6 on volts is crap to tho

That's something I've looked at also. Getting 14.3 at alternator and like 13.4 at the pump idling. 13.9 at fuse block and somehow diminishes at the ECM

 

[Mike T]

Just finished pulling the trans and found the front pump and converter hub to be broken. Hope to be rolling again soon so here is the file.
Thanks

 

[TurboBuRick]

Looks to me like it might be the tune. Post your setting in the high load tune page of the Tpro.

You broke the trans with low boost?

 

[Mike T]

Looks to me like it might be the tune. Post your setting in the high load tune page of the Tpro.

You broke the trans with low boost?

Rick I didn't mess too much with load setting over 2800 RPM other than main scale which I reduced by 7% to clean up a fat condition across the board.
Starting to think the trans damage was due to rpm rather than power......got up on the rev limiter (log showed 6300) before I could get out of it. Don't think it was pump engagement issues either the witnesses marks on the hub look to be in spec.

 

[Nigel]

My observation is that everything dips, even your TPS takes a small step change down just before the dip. Once you get your trans back together, and if you hold WOT and get a dip - i.e. no TPS change, I would be more concerned. If in fact you did not change the peddle and you have everything taking that dip, then you will need to start digging in deeper.

 

[Mike T]

Good observation, I noticed that too. To me the tps drop didn't seem proportionate to boost/rpm drop?? I do have an adjustment for tps decay and possibly it's set too high?

 

[Nigel]

I run my MAFT in translator mode for simplicity, so not exactly sure but Bob would have to comment on the log. In speed density the TPS plays a part, if you lifted slightly and the speed density calculation reduced the air flow signal based on TPS, but in reality the air flow stayed close to the same, you would get a lean condition. Might be as simple as that.

 

[TurboBuRick]

I have never heard of a breaking a trans with rpm. Maybe it was already hurt and just couldn't hold on anymore?

Looks to me like the tune starts to lean out as rpm goes up. The low and mid tune may be good with the lower mainscale setting but wot no likey. You can target that area in the high tune settings. I would add fuel @4000 rpm and up in the high load tune.

WOT correction would definitely help in this situation.

TPS Decay has to do with enrichment fuel when the throttle is pressed. It has no effect on throttle lift.

 

[TurboBuRick]

Duplicate...

 

[Mike T]

Thanks everyone for the help. Rick the trans is an older low mileage EA stage 2 and the converter is PTC 9.5 N/L. Looking at the log things got pretty violent when it got up on the rev limiter and all I can figure is that the pump must have been taking a heck of a beating......

Was doing a couple of things at once, when it got on the limiter I bumped the shifter manually and it seems as if that's when it happened. Would have bet the farm the forward drum broke....... but the pump is the culprit. Spent this morning playing transmission guy.