Funky Rev-Limiter Like Symptom GTO

[E.A.]

I am sure I will figure this out, but it was so weird I had to post it.
Look at the photo of this log.

MAF G/s Drop off, and back up.

yet

MAF Hz Still keeps going?


Car acts like it hits a revlimiter. This is the car that had the major messed up HPTuners Custom OS (2bar) tune in it. I wonder if this is a hardware issue (MAF) of if me doing a full layover with a new EFIlive tune, somehow left something behind. I already swapped out the MAF and still and having the same issue. Any ideas?

Time will tell, had to share though.
Erik

[swingtan]

The usual response....

Post the tune and a log.

I'd like to see a WB reading as well ( it's off the bottom of the graph ) , but looking at the NB voltages it doesn't indicate that fuel was pulled at the same time. Finally, TP% is not a great PID to log as it doesn't always give an accurate indication of what is going on. Given it's an ETC vehicle, I'm guessing that TC / Torque management may have kicked in and closed the throttle.

need to see the tune though.

Simon

[GMPX]

It's been so long, but don't we have a MAF error patch on the E40 for this problem?

[gmh308]

Though very odd to see the MAF freq top out to 22khz. :doh2:

[E.A.]

Its odd that if I give it half throttle it goes right past this mystery "4600" mark.
It will repeate this down to the T, on the Dyno.

(No I don't run a wide band through EFIlive, cause I am sick and tired of the POS LC-1's going bad. I run a much higher grade wideband logger for my tuning)

I leave TP logged because of issues I have had with allison tranny trucks not giving full throttle, if there is issues with the tranny tune. So I do agree that its not the best to log.

It does cut fuel when this MAF drop out happens. But that doesn't surprise me since the MAF tells it to drop out the fuel. Now which comes first the chicken or the egg, thats the question.

I am gonna have the ECU reflashed by the dealer, and then lay this tune back over it. I am still wondering if part of the crappy HPT file, is causing issues. And when I mean crappy..... this car made 408rwhp total when it came in, now even on the 4600 revlimiter its already over 500rwhp.

I'll post my findings tomorrow.
Thanks for the ideas so far!
Erik

[joecar]

Its odd that if I give it half throttle it goes right past this mystery "4600" mark.
...Erik,

Sound to me something to do with abuse mode... I don't know what exactly...

I have seen this on the 3.4L V6's where if you go WOT at no load some kind of limiter kicks in, but if you go PT then you can rev all the way to redline.

[E.A.]

Tried three things at the same time, so I don't know what fixed it, but it did.

E40 Maf patch (thanks to our wonderful EFIlive boys)
Shift Light Moved up to 8192 (even though it doesn't have one)
Torque Limits Removed

Runs like a champ now! Can't wait to put her back on the rollers tomorrow.
I love these cars, with blowers and cams. Run like OEM stock, get better milage then stock, and rock the rollers to over 600rwhp every time.

Thanks all, for the suggestions! It totally helped!
Erik

[Mike@sic]

im having the exact me issue, i know this is an old thred and i hate to bring it back but this car is driving me nuts now. ive been searching for the maf patch for the e40's, is there anyone that can steer me in the right direction (link) on where to DL this. thank you
**---EDIT---*
my mistake i just found it in the software, im going to give it a go hopefully this works, if not i guess SD i go.

[joecar]

Mike, let us know how it turns out...

[Mike@sic]

Mike, let us know how it turns out...

who can i kiss?!?!! i love efilive !! by far the best software i have ever worked with. it worked out great, the car is making a ton of power and clear (well spinning the tires) all the way through the rpm range. now my customer is going to be terrified to drive this thing. Thank you everyone for your help and dealing with my newbness ! thanks guys !!

[joecar]

Good deal :cheers: which table was it (what table id)...?