Common KR Issue on 04+ GTP's
05-26-2011, 01:23 AM
#1
Member
Posts like a V-Tak
Thread Starter
Join Date: Dec 2010
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
Common KR Issue on 04+ GTP'*
Car: 2004 Grand Prix GTP Competition Group, 3.6 pulley, SD Headers, 180 tstat, Custom Tune, thrush resonator, egr/cat delete, Autolite 104 copper core plugs (new), 10mm wires
So I've got a tough one for ya guys, and I hope some of you are up for reading this all.
For the longest of time (since stock) I've had Part Throttle KR. After messing with downpipes and plogs I moved to headers, thinking it would help, but it didn't still saw spikes of KR rise at some start ups. This would go away over time once I got headers and was running knock free on WOT runs even with smaller pulley. I've heard this could be my torque converter locking up and that it creates KR because of this.
A lot of guys who own the 04+ GTP'* have been plagued by this Part Throttle KR. I'm seeing zero KR even on cold nights when doing WOT.
So I've got a tough one for ya guys, and I hope some of you are up for reading this all.
For the longest of time (since stock) I've had Part Throttle KR. After messing with downpipes and plogs I moved to headers, thinking it would help, but it didn't still saw spikes of KR rise at some start ups. This would go away over time once I got headers and was running knock free on WOT runs even with smaller pulley. I've heard this could be my torque converter locking up and that it creates KR because of this.
A lot of guys who own the 04+ GTP'* have been plagued by this Part Throttle KR. I'm seeing zero KR even on cold nights when doing WOT.
05-26-2011, 06:39 AM
#2
DINOSAURUS BOOSTUS
Expert Gearhead
I'm good friends with a couple of the guys that pioneered tuning. One of them said to me "Bill, I've never come across false knock that couldn't be tuned or mechanically fixed." Meaning, unless something is loose or rubbing, all knock can be found in the tune.
There are still plenty of tables that we can't see. We know that at best we have a couple of fueling tables that we are missing which is why we fudge our injector table etc to get close. DHP, Eddies Table Modifier, Tiny Tuner and HPT all clearly overlap a bit and have stuff that the next doesn't .....yet there is still a ton more that we don't have access to.
Likely you have a modifier table (probably visible) that is messing with you. PE, EGR, COT etc are common ones to mess with us on part throttle. Best way to combat this is to dig deeper into tuning, read until your eyes bleed at all the tuning forums available and test/check stuff. Sooner or later you will come across it and figure it out.
There are still plenty of tables that we can't see. We know that at best we have a couple of fueling tables that we are missing which is why we fudge our injector table etc to get close. DHP, Eddies Table Modifier, Tiny Tuner and HPT all clearly overlap a bit and have stuff that the next doesn't .....yet there is still a ton more that we don't have access to.
Likely you have a modifier table (probably visible) that is messing with you. PE, EGR, COT etc are common ones to mess with us on part throttle. Best way to combat this is to dig deeper into tuning, read until your eyes bleed at all the tuning forums available and test/check stuff. Sooner or later you will come across it and figure it out.
05-26-2011, 07:56 AM
#3
Retired Senior Admin
Expert Gearhead
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Likes: 0
Received 28 Likes
on
24 Posts
I'm dealing with the same problem. KR as high at 14.9* at about 10% TP and 1400-1800 RPM. I've adjusted my tune several times with no change. As bill knows from the countless PMs, I've also rebuilt my engine and replaced parts. Do you also see this KR when in park? I did. I unbolted my torque converter and the KR looks to be gone. You can try the same thing. Just unbolt the torque converter from the flex plate, slide it over and start the engine.
05-26-2011, 02:05 PM
#5
Retired Senior Admin
Expert Gearhead
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Likes: 0
Received 28 Likes
on
24 Posts
I found this GM bulletin.
Customer concern of poor acceleration, detonation or "ping" at idle in drive or reverse, and/or possible DTC P0101, P0106 and/or P0121 set in the PCM. The vehicle will perform properly after attaining a speed of about 30 - 40 mph. The condition may also be described by the customer or the dealer as a hesitation, stall when putting into gear, surge on acceleration (similar to hitting fuel cut or rev limit). The ultimate cause may be a non-holding torque converter stator or damaged stator support shaft within the automatic transmission.
Note: A torque converter or stator spline concern will not effect engine operation in park or neutral i.e. misfire or rough idle.
Recommendation/Instructions:
The following checks should be performed in the event that normal engine driveability checks have not resolved the detonation or "ping" at idle in drive or reverse, lack of power from a stop, stall, surge on acceleration and or hesitation complaint.
The IAC counts throttle angle and/or MAP voltage and KPA should be compared to a like vehicle in park and in gear after reaching operating temperature. If the counts and map are high or throttle angle is open excessively in comparison this may be a result of high engine load and a torque converter and or stator support shaft related concern.
If the above information does not lead to a resolve follow torque converter diagnostics listed below.
The transmission oil cooler outlet line (line to the cooler) should be checked for excessive heat. The Tech II scan tool may be helpful on vehicles equipped with the transmission fluid temperature sensor in the cooler line (mainly front wheel drive). On vehicles that do not have the temperature sensor in the cooler line a temperature probe should be used to check the temperature. The temperature readings should be compared to a like vehicle with the same powertrain option content.
A stall test (brake torque) may point to a damaged torque converter, the stall RPM speed will be lower then a like vehicle. However, poor engine performance will also produce a lower stall speed RPM.
If the torque converter stator or stator support is suspect, the transmission should be removed and THE STATOR SUPPORT SHOULD BE INSPECTED FOR SPLINE DAMAGE. If the stator support splines are damaged the transmission should be repaired and new torque converter installed. If damage is not present on the stator support the concern is either internal to the torque converter stator or an engine performance concern.
Note: A torque converter or stator spline concern will not effect engine operation in park or neutral i.e. misfire or rough idle.
Recommendation/Instructions:
The following checks should be performed in the event that normal engine driveability checks have not resolved the detonation or "ping" at idle in drive or reverse, lack of power from a stop, stall, surge on acceleration and or hesitation complaint.
The IAC counts throttle angle and/or MAP voltage and KPA should be compared to a like vehicle in park and in gear after reaching operating temperature. If the counts and map are high or throttle angle is open excessively in comparison this may be a result of high engine load and a torque converter and or stator support shaft related concern.
If the above information does not lead to a resolve follow torque converter diagnostics listed below.
The transmission oil cooler outlet line (line to the cooler) should be checked for excessive heat. The Tech II scan tool may be helpful on vehicles equipped with the transmission fluid temperature sensor in the cooler line (mainly front wheel drive). On vehicles that do not have the temperature sensor in the cooler line a temperature probe should be used to check the temperature. The temperature readings should be compared to a like vehicle with the same powertrain option content.
A stall test (brake torque) may point to a damaged torque converter, the stall RPM speed will be lower then a like vehicle. However, poor engine performance will also produce a lower stall speed RPM.
If the torque converter stator or stator support is suspect, the transmission should be removed and THE STATOR SUPPORT SHOULD BE INSPECTED FOR SPLINE DAMAGE. If the stator support splines are damaged the transmission should be repaired and new torque converter installed. If damage is not present on the stator support the concern is either internal to the torque converter stator or an engine performance concern.
Thread
Thread Starter
Forum
Replies
Last Post