90mm issues redux
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,084
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90mm issues redux
After the explosion in my driveline last weekend, the car got fixed up and suddenly the 90mm TPIS attached to my LSx intake appears to have an attitude again.
Upon putting the clutch in the revs shoot to 2500-2600 rpms at any point, sometimes higher. However, it still idles as before and doesn't hang at stoplights like it used to. Occassionally it gets the automated cruise control back as well.
What would cause one portion of it's bad behaviour to come back but not others?
It was fine for almost 2000 miles, then whoop, back to bonkerland.
On a related note, once the winter comes, should I have the PCM reprogrammed when I throw back on the LS6 or would it be alright as is. This thing is too much of a PITA for my blood.
Upon putting the clutch in the revs shoot to 2500-2600 rpms at any point, sometimes higher. However, it still idles as before and doesn't hang at stoplights like it used to. Occassionally it gets the automated cruise control back as well.
What would cause one portion of it's bad behaviour to come back but not others?
It was fine for almost 2000 miles, then whoop, back to bonkerland.On a related note, once the winter comes, should I have the PCM reprogrammed when I throw back on the LS6 or would it be alright as is. This thing is too much of a PITA for my blood.
Le Mans Master
Joined: Jun 2004
Posts: 7,155
Likes: 154
From: The Arid Sunny Desert
My revs shoot up to between 2500-3000 RPM immediately once I fire her up after sitting for awhile. She then dips down to 300 RPM and the car sounds sick and then whamo right back up to 2500. Once warmed up the idle is just fine and she behaves as expected. Hard to figure and when this cold starting issue occurs, it varies from not too bad to screaming.
Melting Slicks
Joined: Mar 2003
Posts: 3,116
Likes: 10
From: Macomb MI
Dave,
The High BARO and the cold air we are having is most like the culprit.
If it was border line before and near the end of the computers ability (IAC range) to close off the TB air this will happen.
On a light note, LS2 intake and Throttlebody. You will make the same power with zero drivability issues. THe only problem is the tune for idle conrols will have to be moved back near stock.
Phil
The High BARO and the cold air we are having is most like the culprit.
If it was border line before and near the end of the computers ability (IAC range) to close off the TB air this will happen.
On a light note, LS2 intake and Throttlebody. You will make the same power with zero drivability issues. THe only problem is the tune for idle conrols will have to be moved back near stock.
Phil
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 3,084
Likes: 0
Originally Posted by RoadRebel
Dave,
The High BARO and the cold air we are having is most like the culprit.
If it was border line before and near the end of the computers ability (IAC range) to close off the TB air this will happen.
On a light note, LS2 intake and Throttlebody. You will make the same power with zero drivability issues. THe only problem is the tune for idle conrols will have to be moved back near stock.
Phil
The High BARO and the cold air we are having is most like the culprit.
If it was border line before and near the end of the computers ability (IAC range) to close off the TB air this will happen.
On a light note, LS2 intake and Throttlebody. You will make the same power with zero drivability issues. THe only problem is the tune for idle conrols will have to be moved back near stock.
Phil
p.s car feels good...for now
hammered it for a bit and no shafts of any kind snapped.
Melting Slicks
Joined: Mar 2003
Posts: 3,116
Likes: 10
From: Macomb MI
Originally Posted by The DBK
I totally didn't think of the weather until I walked outside this afternoon, and I'm sure that's alot of it. I'm definitely thinking about that LS2 for the winter, and although I'd have to retune to it, it'd be more than worth it for the driveability.
p.s car feels good...for now hammered it for a bit and no shafts of any kind snapped.
p.s car feels good...for now
hammered it for a bit and no shafts of any kind snapped.Hahah..good, schedule is full for a bit..Earls toasted the clutch and has some other stuff he needs..
I suggest a copy of LS1 edit for youself...you can tweek and play and the price is right in the long run. I can help you thru it.
Phil
Safety Car
Joined: Mar 2002
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Cruise-In V Veteran
St. Jude Donor '09
Originally Posted by Pewtavert
My revs shoot up to between 2500-3000 RPM immediately once I fire her up after sitting for awhile. She then dips down to 300 RPM and the car sounds sick and then whamo right back up to 2500. Once warmed up the idle is just fine and she behaves as expected. Hard to figure and when this cold starting issue occurs, it varies from not too bad to screaming.
Le Mans Master
Joined: Jun 2004
Posts: 7,155
Likes: 154
From: The Arid Sunny Desert
Originally Posted by Bink
Do you have LS1- Edit or HP Tuners?? What is the Intake Air Temp ( IAT) at start up when the over-rev occurs???
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Le Mans Master
Joined: Jun 2004
Posts: 7,155
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From: The Arid Sunny Desert
Originally Posted by pdd000
i have no idle issues what so ever,no cruise control. but sometimes at stop lights it stalls or the idle hunts
Team Owner
Joined: Jul 2003
Posts: 20,474
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From: Detroit
Originally Posted by Pewtavert
According to Nick Williams there should be no idling or driveability issues whatsoever.
Mark
Le Mans Master
Joined: Oct 2002
Posts: 6,799
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From: dudley MA
Originally Posted by mdhmi
Easy for him to say. I'm not trying to slam anyone, but, I've nothing but horror stories about that TB.
Mark
Mark
Drifting
Joined: Jul 2000
Posts: 1,289
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From: the West is the best
pdd- are you saying that you don't get the "cruise effect" when you have the AC turned on with NW 90mm TB? By the way, by cruise effect, I am referring to the weird cause and effect that occurs when the AC is turned on and the idle does not want to drop when shifting gears (up or down). The idle will drop, of course, but at it's own sweet time. To me that is the MOST irritating negative of the TPIS 90mm TB.
Safety Car
Joined: Mar 2002
Posts: 4,928
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Cruise-In V Veteran
St. Jude Donor '09
Originally Posted by mdhmi
Easy for him to say. I'm not trying to slam anyone, but, I've nothing but horror stories about that TB.
Mark
Mark
Pro
Joined: Mar 2002
Posts: 712
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From: Santa Clarita Ca
Originally Posted by Bink
What horror stories have you heard???
I agree with Bink, I'd like to hear these stories because I have nothing but good things to say about the ease of tune and quality of the Mark Williams TB....and I am not without a fair amount of knowledge and experience in tuning them.
FWIW, the TPIS is a handful but even those can be tuned to run and idle without issue.
Melting Slicks
Joined: Feb 2002
Posts: 2,613
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From: Winston Salem NC
Originally Posted by 2ndVette
pdd- are you saying that you don't get the "cruise effect" when you have the AC turned on with NW 90mm TB? By the way, by cruise effect, I am referring to the weird cause and effect that occurs when the AC is turned on and the idle does not want to drop when shifting gears (up or down). The idle will drop, of course, but at it's own sweet time. To me that is the MOST irritating negative of the TPIS 90mm TB.
I have "no" issues with Nick's TB. If your car is tuned and running well when you put Nick's TB on, it will need little or no tuning. The tuning issues seem to occur when other changes, such as a cam, are made at the same time. I believe the TPIS problems have created a bad image for 90mm TB's.
There should not be a difference in running rpm's with A/C on or off.
If the car was tuned during warm weather the fact that the tune at lower temps was not right wasn't apparent. You are not out of IAC range. Think of it as if your setting a choke on a carburator. It can't be done until it's cold out.