The photos that are posted aren't what my 96 uses and since GM changes things so often, you need to make a comparison. My connector plug won't even plug into the ones in the photos.

If I post what my engine calls for in idle rpm it could be different from yours for the same reason - GM changes. So I don't want to give you incorrect information so it's best for a 91 guy to give you that idle number.

Engines that have a non-adjustable TPS are non-adjustable for a reason: the PCM controls it's voltage automatically and has a very wide range of what voltage is within spec.

Jake

 

Finally dragging out my manual, it says that the range is 0.3 to 0.9V. I take it that in between is fine. Anyone disagree?

 

I checked my scanner and the desired idle is around 800-900 depending on the engine temp. Not only did GM change the idle speed, the guy programming the chip also did change it to make it run better with the intake, heads and cam combo.

I read up and THINK the spec is 0.3 to 0.9 with the throttle closed.

 

What does your scanner say the TPS volts are with the throttle plates closed?

 

Don't know. With the old part that as slotted, it was set to 054V. That unit was driven on by the wife. That is why I have to get a new unit.

I thought of getting the adjustable one straight off so that if it falls outside the range, I don't have to worry. If I get the correct one, I might have to worry if it gets out of range. At least that is the thinking. I could be following a flawed line of logic so I thought I'd ask the general consensus.

 

The Vette FSM for the 96 says: ". . . about .6 volts at idle." "The TPS has a 5.0 volt reference, a ground and a signal circuit". "The TPS sensor voltage should increase to above 4.0 volts at wide open throttle (WOT)."

"The signal voltage is one of the most important inputs used by the PCM.".

Since you found your voltage range, I'll find mine (for the 96) if you still need me to.

Jake

 

Probably not since I already know my range and will slot the TPS if necessary. Also, 91 and 96 will be way different but thanks for the offer. If there is something I can do for you in the future, feel free to ask. I'd give you my first born son for your effort. Since we don't have kids, I can make that offer.

 

Here's how I see it: If the factory originally designed your system for an adjustable TPS, then that's what you need to do. The ECM circuitry will be looking for the voltage from the adjustable differences an adjustable TPS creates.

When you install the new adjustable TPS, you much use a digital volt meter to set the voltage at .V (+/- .075) which is the range of adjustment allowed before a code will. You can do the math to see how high you can set the voltage before a code will set.

On my 86, which had an adjustable TPS, I could get .V before a code set. I have to add that on the 86 I DID NOTICE a difference with the .V setting. Throttle response was more immediate, however this was on a 415 CID engine which probably was a big factor.

GolenEngines.com for NON-ADJUSTABLE TPSs, the hole be elongated and the voltage set at .V. I did that on both my 388 CID LT1 and on my son's 96 LT1 (350 CID with Dart heads, custom CompCams HR cam and high ratio rocker arms) but in neither case did it make a noticeable difference. I didn't get anything close to the feelings I experience when I did the same thing on the 86 Vette.

If I were you and IF the system is setup for an ADJUSTABLE TPS, I'd set the Engine OFF; Key ON voltage at the high end of the range and give it a try. If you don't get the expected results, you can always back off on the voltage setting; easy to do.

Just be sure to re-check the setting once the screws are tightened because the voltage can change as you tighten the screws.

Hope this helps.

Jake

 

ROFL!

Jake

 

The book was right. Whoda thunk it!!

I borrowed a round hole one from a neighbor's car to try. I was setting the min idle speed and had to screw it back. ECM didn't react well because it was going against the min voltage that it was expecting. Shut down and restarted. Life was good. Got the min idle. Now I know what I need to do. It was about 0.7V and some change. When I loosened the screws, the idle didn't drop and the IAC counts didn't change much so I shut down, restarted and like magic, it worked. Now we know

 

Pete and Jake are correct. Golen has a good step by step instruction. I have a 91 with 58 tb, once you set the minimum idle set it to .54v

 

Golen Engine Service

 

So you used a NON-ADJUSTABLE type and got good results, right?

Is that the type your year engine calls for?

Seems like you're on the RIGHT track. I know that's a good feeling.

Jake

 

So far. No blood too.

Yes it is.

VERY.