Nasty flat spot at 4100rpm at WOT vy v6

[Roosterinwa]

Hi all, bit of a curly one... The issue is this...

Have done some mods to my vy v6 crewman, stage 2 comp cam, 69mm TB, CAI, 12mm plenum spacer and 25mm inlet manifold insulator... Stage 2 shift improving kit (B&M), 2500rpm lockup torque cornvertor... And ECU remapped to suit all mods.

It drives very well as a cruiser, doesn't miss a beat except occasionally stalling at idle when turning the wheel and when i have aircon running...

But, at WOT takes off very well considering the cars weight but at WOT once it hits 4100 rpm it dies in the arse and if I hold throttle the engine warning light comes on and auto then stays in whatever gear it was in when fault was triggered, if I back off the throttle a little till it gets to 5000rpm it then powers on to shift point...

When logging I cannot reproduce the fault with the cable connected for some reason...

Any help with this would be fantastic...

[damiandownie]

Do you have the hardware/knowledge to be able to extract a bin file for us to look at? Also was the stage 2 comp kit from Mace Engineering, i wacked my semi std chip in and was remarkably better than the tuned one but it hardly stalls now with ac and in the parking lot

[Roosterinwa]

Thankyou damiendownie for your quick response..

Yes, it is a MACE kit & been told for privacy information to not freely allow the tune on the open market!

I have added a log file that should reflect flatspot at 4100rpm, the log has a few standing starts, all (from memory) takeoffs are with WOT


Interesting, i've seen on a few forums a barely modified tune wouldn't really work too well with a stage 2 comp cam & could cause long term issue's if left un-tuned! How much was your chip tune different from standard??

[Holden202T]

can you also post up the ADX you used to log ?

i dare say the stall issues are probably requiring a bit more throttle opening or IAC settings tweaked ...

when the engine light comes on have you seen what code it is producing ? ie. is it something like o2 sensor lean etc ? the fact that you can back off and drive through it sounds like a lean condition in the tune somewhere.

[damiandownie]

The current chip im running has a few adjustments on the high/low oct tables, some PE enrichment etc, high/low oct tables are increased by about 5-10 on majority of them. I thouroughly investigated (about a month studying the files and comparing)before i did the swap over on the chip from the cam package to the one im using

[Holden202T]

dead set if anything 12.9 is lean and 12.6 is almost bang on where you'd want it! i doubt that would cause a flat spot bad and an engine light!

[Roosterinwa]

can you also post up the ADX you used to log ?

i dare say the stall issues are probably requiring a bit more throttle opening or IAC settings tweaked ...

when the engine light comes on have you seen what code it is producing ? ie. is it something like o2 sensor lean etc ? the fact that you can back off and drive through it sounds like a lean condition in the tune somewhere.

Hi Holden202T, thankyou for your assistance...

I am using the standard Adx file supplied with TP5...

as for the engine light... whilst logging, i have been unsuccessful to reproduce the engine fault that i get whilst not logging....

Once i connect to TP5 for logging or tuning it comes up with an engine fault and an SRS light.

Which kinda makes it hard the see a fault triggering...

The only code that i can see that is ongoing is the DTC 92 code low fan communucation failure is SET

One thing that i have noticed is that at WOT TP5 tells me that TPS voltage is RED at 4.16v then creaps down to about 4.06v... idle TPS voltage is about 0.55

[VL400]

Yes, it is a MACE kit & been told for privacy information to not freely allow the tune on the open market!

They should really come to the party and fix the tune if thats the case. If it wasnt for the FREE delcohacking flashtool they wouldnt be selling tunes for these cars

Anyway, the log does show a fair bit of what is happening and why it has a flatspot.

[Roosterinwa]

Yes, it is a MACE kit & been told for privacy information to not freely allow the tune on the open market!

They should really come to the party and fix the tune if thats the case. If it wasnt for the FREE delcohacking flashtool they wouldnt be selling tunes for these cars

Anyway, the log does show a fair bit of what is happening and why it has a flatspot.

Hi VL400, Great to hear from you, Great forum... Read a lot of your posts.. Very informative

I am working with them to fine tune the ecu with that awesome Flashtool (thankyou Delcohacking)

But unfortunately with said vehicle being in another state and needing to do everything via chinese whispers so to speak lol, im a monkey, monkey see, monkey do and for the most part it has been fantastic service, i do however think that my issue may not entirely be tune, i have a B&M shift improving kit installed... (nothing done to solonoids or anything like that but the 1-2 acc springs were removed and a spacer fitted, and one specific hole in the transgo place was slightly opened up... so basically a poor mans shift kit lol, worked really well whist engine was stock.

not sure if that could be affecting it in some way...

[VX L67 Getrag]

damiendownie.... if your talking about a chip/eeprom type tune it's a completely different animal & different tune/tuners so there not even comparable but good to throw in ideas!

HOLDEN202... these things are actually set to factory @ 13 PE but have timers & other modifiers to bring them richer the longer there in PE, I'm sure the tuner tried all the different PE settings on a dyno & came up with the best power/torque curve to suit the AFR & timing mix!

VL400... I believe MACE have been trying to sort this out & without being able to get a log of when the fault happens it makes it very difficult to fault find which is why i'm guessing he's come on to the open forum to get ideas from more experienced array of people.
I also think the log may have been with LTFT disabled & possibly before the base injector rate was closer to suit that particular vehicle as the long & short term fuel trims were almost maxxing out previously.

ROOSTERWINA... I'd be guessing but if you had the trans heavily modified before the cam & it ran fine, than maybe there is no issue there, but really need to get the tune closer & then log it till the error happens, I know it's hard to tell with light already being on but if it's that noticeable when it happens you should be able to tell that way!

EDIT: Just had a look at the log & LTFT definitely not enabled & wouldn't advise driving the vehicle like this!!!!(long term)
But not only that the o2 voltage is very split for areas so the inj mul table will need to be modified from the logs to get the fulling closer to correct, looks like its way too rich up top & too lean down low!