fuel cut on boosted suburban

[EFIExpress]

Hi,

I'm tuning an 02' suburban with a twin turbo setup, HP Tuners 2bar speed density OS mode applied.

The problem I'm running into is a fuel cut that is occuring around 4000 rpm on the dyno. Near as I can tell, I've got all relevant fuel cuts disabled (traction control, trans abuse, etc). I'm positive its a fuel cut, you can watch injection percentage slam to zero in the scanner when this occurs.

What other places do I need to look? this is happening well within the limits of both the MAF (which is connected but shouldn't be being used by the tune) and the 2 bar map, cut is happening around 140kpa.

Thanks!

[flame]

You should post the tune file and a log. Not sure if it is cable or drive by wire throttle.

[EFIExpress]

cable throtle, 90mm throttle body. tune and log attached. not sure if the log captured the 0ms cut but its there on the realtime monitor.

[planethax]

Newb here;
But could it be the P0106 error Map Max?

At approx 3800 rpm with a TPS of 65% your Map is at 112Kpa (IDC dropped to 1%)

and in your Tune file I see its set (1 bar still) for a Max of 105Kpa

[EFIExpress]

Newb here;
But could it be the P0106 error Map Max?

At approx 3800 rpm with a TPS of 65% your Map is at 112Kpa (IDC dropped to 1%)

and in your Tune file I see its set (1 bar still) for a Max of 105Kpa

where are you seeing the 105kpa setting (which menu)?

[planethax]

where are you seeing the 105kpa setting (which menu)?

Engine Diag -> Airflow
bottom of that Tab the is
P0106Error MAP Calculated Max

[EFIExpress]

good guess, but no. still does it with those values increased.

[Bill@HPTuners]

I highly recommend properly failing the maf as currently you have it set so the maf doesn't fail until the second error which could be minutes or longer.

Start there.

[EFIExpress]

I highly recommend properly failing the maf as currently you have it set so the maf doesn't fail until the second error which could be minutes or longer.

Start there.

even on a speed density tune? Also the MAF fail high is set to 0, so I'd assume it should fail right away?

[EFIExpress]

changed to fail on 1st error, fail @ 0hz high, dtc shows in the scanner, still same problem.

[Chris@HPTuners]

try deleting all torque management and see if it goes away, you still have max torque at 475 and some of the axle torques are low'ish.

[Nodnarb]

A few things:

Are you using a wideband?
What's your fuel system like?
Which injectors are you using?

Set your High RPM Disable RPM above your rev limit if you plan on running speed density.

Calc Airflow p1514/p0068 table. Increase the values in it.

I'd also take advantage of the Boost Enrichment table.

[EFIExpress]

A few things:

Are you using a wideband?

yes, the vehicle is currently mounted on my chassis dyno, we're monitoring lambda via a separate mechanism.

What's your fuel system like?

42lb injectors, stock fuel pump stock lines. lambda stays nice, .83 under max boost.

Which injectors are you using?

ford 42lb injectors.

Set your High RPM Disable RPM above your rev limit if you plan on running speed density.

Calc Airflow p1514/p0068 table. Increase the values in it.

would that cause 0ms, full fuel cut if it were mis-calibrated?

I'd also take advantage of the Boost Enrichment table.

will play around with it certainly. but need to sort this full on fuel cut first.

[EFIExpress]

try deleting all torque management and see if it goes away, you still have max torque at 475 and some of the axle torques are low'ish.

I set all the bitmasks to 255 per the instructions, is that sufficient to disable torque management, or must more be done?

[Chris@HPTuners]

set all the torque values at max and also the ETC TPS % table to 100, the trans abuse mode, etc. etc.

[EFIExpress]

set all the torque values at max and also the ETC TPS % table to 100, the trans abuse mode, etc. etc.

still cuts with torque numbers maxed and etc tps set to 100 per your instructions.

Keep the suggestions coming, I need to get this car tuned and off my dyno today if possible.

Thanks!

[planethax]

.........


Calc Airflow p1514/p0068 table. Increase the values in it.

.......

still cuts with torque numbers maxed and etc tps set to 100 per your instructions.

Keep the suggestions coming, I need to get this car tuned and off my dyno today if possible.

Thanks!

Calc Airflow p1514/p0068 table

I would have thought that since SD tune this wouldnt matter, however since its a calculated airflow I guess it does.

Increase your numbers there and try

[EFIExpress]

Calc Airflow p1514/p0068 table

I would have thought that since SD tune this wouldnt matter, however since its a calculated airflow I guess it does.

Increase your numbers there and try

no change. adjusted p0068 table (multiplied all values by 10) and still exactly the same cut.

[flame]

Your speed limiter is set to 98mph

[planethax]

Your speed limiter is set to 98mph

Dooh, I see it set at 158 -163 KPH (I use Metric)
Nice catch I never even thought to look there, over complicating everything.

Set speed limiters to 412kph ( 256 mph)