A while back I was using a diacom and went for a drive and noticed that I was not getting WOT (Wide Open Throttle).

It is my understanding that the TPS is not adjustable on the LT1. Can anyone confirm this?

Has anyone adjusted their throttle cables on their LT1's? Preferably some insight on a six speed.

I haven't had a chance to look at the Service Manual.

 

The TPS sensor can be adjusted but you'll have to take it off an elongate the mounting hole for the adjustment. You can use an Ohm meter to check the voltage if you don't have the Diacom still. Other than that, you can turn the set screw on the TB but you have to remove the aluminum cap on the set screw hole. If you're not getting WOT, check the TPS sensor and make the necessary adjustment.

laters,

Rob

 

Duntov,

Rguy is correct,

The TPS is self adjusting.. in other words it looks at the position of the throttle at rest when you start the engine and looks at that as being 0,

one way to test would betake a volt meter and connect one probe to ground and probe pin C with the TPS connected...

turn on the ignition but do not start the engine...

manually move the throttle to WOT (max) you should see in the neighborhood of at least 4VDC..

then have someone repeat the same with by pressing down the gas pedal...

you should get a similar reading...

Hope this helps..

Mo

 

How do you get the probe on pin C with the TPS connection still plugged in? In order for the TPS to get juice doesn't the sensor wire harness have to plugged onto the TPS's terminals? I only ask because I want to try this also. :D

 

Yep, the circuit has got to be completed in order to accurately measure it. One of the pins is 5vdc, one is ground, and the other is the return signal to the ECM.. Basically, its a potentiometer.

One thing to try with the adjustment is to move the adjustment stops on the cables that are closest to the ASR unit. If you're car has an upgraded throttle body or maybe just high mileage.. it's worth trying to move those suckers back and forth just a hair. You gotta push a little hard on the arrows in order to get them to release but they will move.

Easiest way to adjust this is to have the scanner software hooked up and operational and have a friend sit in the driver's seat and press the gas pedal for you and call out the wot readings. You should see the return position in the low .6vdc range.. on the high side, as posted earlier, anything over 4vdc is considered to be wot. I found this out several months ago by hounding a couple guys who are regulars in the ECM section. I was only getting 98% tps feedback and it was driving me bananas! So, long story short, this simple adjustment was all it took.

When you think you've the cable lengths properly adjusted, now it's your turn to jump in the driver's seat. No two people push the pedal the same way.. Just double check it and then repeat it a couple times. Everything should be a-ok if it's repeatable.

 

I adjusted the throttle cable earlier today and used the procedure that is in the service manual. When the acclerator pedal was fully depressed there was probably about another 1/4 of movement on the throttle body before WOT.

I had heard from people that adjusting the throttle was a royal pain, but it was actually pretty easy.

 

I have been searching for aLOOOONG time for anyone who knew how to adjust the cables coming from the Throttle body. Doesnt this have to do with traction control??? what is the procedure.??? :mad

 

I am going to try and make this very simple.

Disconnect the cable going to the cruise control.

By the ASR there is a wierd looking connector on one of the cables. There is a button on that connector, and push that in. This will allow the cable to either shortened or lengthened. Move the cable while holding in the button until just before the throttle starts to open. Now have someone press on the throttle and verify the butterflys are opening all the way, and while you are looking move the linkage to verify that there is no more movement. Once you are satisfied that you are getting WOT, have the person inside remove their foot from the accelerator.

Now it is time to adjust the cruise control. Take the cable that you disconnected from the cruise. Does it line up to any of the holes without causing the throttle to move? If so, put it in the closest hole. If it does cause the throttle to move, relax the tension until it lines up with the closest hole.

You have now adjusted your throttle cable.

 

Here is a photo of the Throttle Cable Adjustment Coupling on my '95 LT1:



Hope this helps.

 

Lone Ranger,

To measure the voltage on pin c you need of course a multimeter with a sharp pin type probe.

Yhe alternative to that would be as was posted as well hook up your scanner software if you own any and check your readings that way...

Sorry for the confusion

:crazy: :crazy: :crazy:

mo

 

Okay, I think I have it, just one more thing... :D ... Does that mean you use the sharp probe to puncture the insulation on the wire to the C pin to get the reading?... and which one is C?

 

I just use a piece or real thin wire, put it in the female end of the desired terminal, and put the connectors together, then connect the multimeter probe to the other end of the wire. The wire has to be a real thin single strand though, otherwise it would be hard to put the connectors together without damaging anything.

 

Lone Ranger,

Yes you would puncture the insulation, or use the other method suggested above. If you look closely at the connector the pins are labeled...

Then again with 3 wires you have a 50/ 50 chance that you get the right outside wire :D

Mo