Thread: 07 Supercharged stalls at high RPM around 6k

Hi all,

My 07 Grand Prix GT Supercharged stall/dies at WOT around 6k RPMs. I had this issue before and after replacing the MAF, Crank Sensor and Harmonic Balancer. The car runs and accelerates fine during normal street driving and when I'm pushing it a bit on the street. When I get WOT on the highway at the 6k RPM range is the issue. Attached are two scans to where it has cut out. Looking at the scan all I really see is that I am close to if not outflowing the MAF during this time. It is very cold here so it may be an issue. I am not very good at deciphering the scan data. Any help or thoughts are appreciated. Unfortunately HPTuners did not log some MAF data in the 1-24 scan. Thanks

Dropbox - 1-4-21 stalled at wot.hpl - Simplify your life

Dropbox - 1-24-21 stalled hig rpm.hpl - Simplify your life

well you got kr out the ass from 3600 rpm to 6k.

dont see a wideband in the scanner whats the afr wot? you got the meth spraying?

if your on a stock cam, lower the shifts to 5800 rpm, you gain nothing spinning to 6k or higher unless its got a cam.

I got rid of the Meth.

The Wideband readings are listed under the EGR/AFR. For whatever reason HPT scanner stopped reading them at the WOT. It is weird though it lists the AFR at one point at 19.6 but the trims at the same time are listed as -5.

I will look at the tune and change the shift points to 5800 as I am on the stock cam. I only have the 1.8 roller rockers and 90# springs.

Do you see any reasons or changes I need to make to get rid of the knock?

Dropbox - 1-10-21 trim and knock after CPK replacement.hpt - Simplify your life

from the file name im gonna guess you screwed with the icm harness/CMP/CKP stuff?


more than a dozen times ive come across this sort of under high load stalling/stutering/stalling is related to the harness being improperly routed/secured and shorting out omn the ac compressor pulley/back of crank pulley/etc.


always start with the most recent repairs and verify nothing went wrong before guessing on causes

on highway speeds the airflow under the hood is high enough to push harness wires around....leading to an intermittent loss of crank possition.

give me your email addy, ill send you my tune to compare, you could likely use my whole trans tune, and your timing seems high and you still have the timing adders on. and tune up the knock sensors in the retard tab under spark. your pe is also way to rich, copy mine over, and i dont see a wb reading any where on the scan.

I just made sure the harness is secured and it looks ok. I also inspected it when I replaced the sensor. This issue was going on before the replacement as well. I had random stalling issues that led me to replace the sensor in the first place.

As for the transmission settings can someone refresh my memory on where to adjust the rpm speed and what the settings should be. I just tried to look it up but everyones settings are different. I think my Transmission settings may be leading to crappy gas mileage as well.

here is where I think I adjust the shift RPM. What should they be at? Dropbox - Screenshot 2021-01-24 14.20.10.png - Simplify your life

I really appreciate your guys' input!

I must be doing something wrong with the scanner for the wideband readings. It is what I thought under EGR/AFR settings in the scanner. I have a PLX installed to read through the EGR readings.

Dropbox - Screenshot 2021-01-24 14.46.47.png - Simplify your life
Dropbox - Screenshot 2021-01-24 14.47.25.png - Simplify your life

sorry this is the only way I know to get pictures posted.

if your sure the harness is ok near all the spinny stuff, wigle the icm long gray connector and move the harness to check for a stumble, those terminals are known to open up as people excessivly wiggle em or let em cock at an angle while unscrewing the retaining bolt.

use a small sewing needle to tst each terminal for grip tension. it may be your losing the 7x signal from the icm to the pcm. its one of the few ways to end up with a high rom stall/intermittent

heres the vid to hook up a wide band right. make sure you save the layout when your done. or it can all go away.

i sent you my scanner layout too, has more stuff logged.

please confirm that is a factory/OEM iCM? make sure the grommet inside the electrical connector is the orange color, NOT GREEN/RED like an aftermarket icm. the heatsink plate should be aluminum, if its steel/plated steel or SS replace the ICM with a facttory unit

Originally Posted by rickisrad

I do have an aftermarket ICM in there.

I think I should change out the spark plugs as well. I still have AR103 racing plugs in there from when I had the E85 and Meth. Gapped at .045. Probably too cold of a plug. It is a daily driver and I have a good set of TR6IX that I will probably throw back in there gapped at .050. I have a long commute to work and could use a little better gas mileage anyways.

ding ding ding! we have a winner.

before you go jacking with anything else, swap it out with a good orange grommet GM/ACDELCO ICM from any 3800 equipped car in the junkyard.

most people dont want to pay for a new genuine acdelco from a parts store and it has been my experience that ive had issues with 4 of 6 aftermarket ICM's over the years.

i keep a stack of good used oem acdelco icm's and blue coils because is still see this issue.

any 97-09 3800 SII ICM is what you need, NA,SC, desnt matter. bring a 7mm and a 5.5 and 5mm sockets (5mm if yer in th erust belt and the bolts hex is rusted undersize