TB cable adjust made a difference...
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Le Mans Master
Joined: Feb 2002
Posts: 7,858
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TB cable adjust made a difference...
My throttle body butterflies weren't getting full open with the pedal to the floor! The control arm assembly for the butterflies lacked hitting the stop by maybe 3/8". Made the adjustment... there's a Sweet Spot to be found for sure. Best throttle range performance/response was found when the adjustment was such that with the pedal held to floor for WOT the butterfly arm assembly stop was held against the throttle body housing with a slight firmness, and not hammered hard-pressed against it. I don't know why this is, but my SOTP meter indicates this is the best tb cable setting for throttle response on my ride. :yesnod:
Melting Slicks
Joined: Aug 2001
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Re: TB cable adjust made a difference... (95_C4_convertible)
How did you adjust that bad boy?? I thought from the ASR to the TB that it was "non-adjustable".?? I'm guessing with the bracket that bolts to the side of the manifold, no? I'm curious... I've got a tough time making my TPS see the 4.0vdc for WOT... thanks.
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From: SE NY
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Re: TB cable adjust made a difference... (EricVonHa)
I think he means that the TV cable was keeping the throttle plates from opening fully. This cable has a tang that when depressed releases the cable so that the little nose piece in the front can be pulled forward. Usually if it's holding the throttle plates back just pressing the tang while holding the throttle full open will cause the TV cable to pull forward enough to let the throttle close fully.
If you're having getting the TPS over 4.5 Vdc at WOT try rocking the top of the unit about the lower bolt. Also you can set the base voltage to about 0.65Vdc before you cause the ECM to throw a code. This will show the ECM that the throttle is further open and move up on the fuel and timing curves.
If you're having getting the TPS over 4.5 Vdc at WOT try rocking the top of the unit about the lower bolt. Also you can set the base voltage to about 0.65Vdc before you cause the ECM to throw a code. This will show the ECM that the throttle is further open and move up on the fuel and timing curves.
Thread Starter
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Re: TB cable adjust made a difference... (65Z01)
I think he means that the TV cable was keeping the throttle plates from opening fully. This cable has a tang that when depressed releases the cable so that the little nose piece in the front can be pulled forward.
I don't know how else to word it... I'm by no means an expert but this needed to be done on my car.
Thread Starter
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Re: TB cable adjust made a difference... (EricVonHa)
How did you adjust that bad boy?? I thought from the ASR to the TB that it was "non-adjustable".?? I'm guessing with the bracket that bolts to the side of the manifold, no? I'm curious... I've got a tough time making my TPS see the 4.0vdc for WOT... thanks.
Now, how can you tell whether or not your Throttle Position Sensor is reading the movement correctly? I'm totally new at this.
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Re: TB cable adjust made a difference... (65Z01)
________________________________________ _______________________________________
If you're having getting the TPS over 4.5 Vdc at WOT try rocking the top of the unit about the lower bolt. Also you can set the base voltage to about 0.65Vdc before you cause the ECM to throw a code. This will show the ECM that the throttle is further open and move up on the fuel and timing curves.
________________________________________ _______________________________________
um i don't quite understand....can you please elaborate>....sorry Iam a bit slow when it comes to this type of stuff...if you could just put in into a little bit more laimans terms, that would be great.....
thanks jeff
If you're having getting the TPS over 4.5 Vdc at WOT try rocking the top of the unit about the lower bolt. Also you can set the base voltage to about 0.65Vdc before you cause the ECM to throw a code. This will show the ECM that the throttle is further open and move up on the fuel and timing curves.
________________________________________ _______________________________________
um i don't quite understand....can you please elaborate>....sorry Iam a bit slow when it comes to this type of stuff...if you could just put in into a little bit more laimans terms, that would be great.....
thanks jeff
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From: SE NY
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Re: TB cable adjust made a difference... (95_C4_convertible)
95_C4_convertible, sorry for my ignorance on the differences from '88 to '95 but sounds like your TB cable adjustment has a similar effect on throttle closure as does my TV cable adjustment. Anyway, congrats on dealing with the issue successfully.
XtremeVette, the TPS on your '90 may not be adjustable. Mine has two slotted screw holes that allow me to adjust the base reading (with the IAC pintel fully extended, per directions on my site). I believe your TPS has two round mounting holes and so is not mechanically adjustable. Also your ECM may auto zero the TPS reading as your drive, whereas my ECM relies on the base reading being manually set. If someone else with a '90 or '91 L98 can jump in here it would be helpful.
[Modified by 65Z01, 12:37 AM 3/24/2002]
XtremeVette, the TPS on your '90 may not be adjustable. Mine has two slotted screw holes that allow me to adjust the base reading (with the IAC pintel fully extended, per directions on my site). I believe your TPS has two round mounting holes and so is not mechanically adjustable. Also your ECM may auto zero the TPS reading as your drive, whereas my ECM relies on the base reading being manually set. If someone else with a '90 or '91 L98 can jump in here it would be helpful.
[Modified by 65Z01, 12:37 AM 3/24/2002]
Thread Starter
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Re: TB cable adjust made a difference... (EricVonHa)
How did you adjust that bad boy?? I thought from the ASR to the TB that it was "non-adjustable".?? I'm guessing with the bracket that bolts to the side of the manifold, no? I'm curious... I've got a tough time making my TPS see the 4.0vdc for WOT... thanks.
[Modified by 95_C4_convertible, 3:59 PM 3/24/2002]
Melting Slicks
Joined: Aug 2001
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Re: TB cable adjust made a difference... (95_C4_convertible)
Thanks for posting the photo of the adjuster... I've always known that thing to be there, but never knew what the arrow was for. Now I know!!
I've replaced a couple gas pedals in my time of owning my LT-1... call it a case of the really serious "lead" foot. I'm thinking that through the geometry of the gas pedal possibly changing a hair and having the ASR system out multiple times to change plugs, headers, etc. that this has effected the(inefficient) operation of the throttle cable system. At WOT, my TPS will barely crest the 4vdc... 4.0x to be exact. 4vdc is all the ecm needs to see to signal wot... but it's a little close if you ask me. Also, on the LT-1, the TPS is non adjustable. Surely one could make it adjustable and monkey with it... but if the system is not showing over 4vdc at wot, it's indicative that there is something else wrong with the system.
So, thanks again for posting the picture along with the adjustment description procedure!! :cheers:
I've replaced a couple gas pedals in my time of owning my LT-1... call it a case of the really serious "lead" foot. I'm thinking that through the geometry of the gas pedal possibly changing a hair and having the ASR system out multiple times to change plugs, headers, etc. that this has effected the(inefficient) operation of the throttle cable system. At WOT, my TPS will barely crest the 4vdc... 4.0x to be exact. 4vdc is all the ecm needs to see to signal wot... but it's a little close if you ask me. Also, on the LT-1, the TPS is non adjustable. Surely one could make it adjustable and monkey with it... but if the system is not showing over 4vdc at wot, it's indicative that there is something else wrong with the system.
So, thanks again for posting the picture along with the adjustment description procedure!! :cheers:
