I've noticed that the power on my LT1 is kinda different than any other car I've driven. Is this because of the throttle plate wheel? (see pic) I don't know what you call it exactly, but its the progressive looking wheel that is at the throttle body. Seems like it makes the car accelerate oddly as you slowly depress the pedal.

I tried to do a search but couldn't find anything. I know I'm not the only one to really notice this. It sounds like a progressive throttle would be a good idea, but its throws off my groove. Especially when I'm heavy into it. Just a little bit of pedal travel makes a huge diff when its wide open. It seems like it would help with off-idle control, but WOT kinda sucks.

Is there any way to convert it over to a round throttle wheel instead of the progressive?

 

I really doubt that would cause your problem. Do you have the right throttle cable. If you are using a thirdgen accelerator pedal, you should have a throttle cable from a TPI thirdgen(not 93-97 LT1 cable, unless you have LT1 pedals).

I'm not really sure what your car's problem is though. If it doesn't accelerate right, it could be a few things. If idle isn't right, also a few things. If it has a high rpm miss, i think thats the opti or ignition control.

 

Hmmm. What I did was used the LT1 throttle cable and made an adapter at the firewall to mount it. Seems to work fine but there could be a little less slack I suppose.

Why do you have to run the 4th gen pedals?

 

Some people run 4th gen pedals when they swap in a 6 speed manual. You don't need them for an LT1 swap or really even for a 6 speed swap. I'm just saying if you use LT1 pedals, you need an LT1 throttle cable. Likewise, if you use thirdgen pedals, you need a TPI cable.

I recommend just getting a new '92 TPI throttle cable from your local GM dealer. I wouldn't think it would cost more than $20.

The LT1 cable is a different length than the TPI cable. Sure, you could fab something up, but it might not be adjusted just right and things might seem weird.

 

get a TPI cable. and your throttle body is fine.


and what do you mean by the power is different? the torque and HP curves are totally different from that of a TPI car, of course its going to feel different.

 

If you have access to a scantool you you can see if your throttle is opening all the way by observing the throttle angle.

 

I'll look into the TPI cable. I tried the 5.0TBI cable, and a 2.8 MPFI cable (I had both laying around). Does the TPI cable have the correct TB end on it?

I'll just use my multimeter, but checking the tb angle is a great idea. Thanks! Now I have some fun weekend projects.

 

Yes, the TPI has the correct end to hook up to the tb. You may have to modify the cable slightly to get it to fit in the bracket.

You don't even need a multimeter. The tb should open the same amount as when you don't have a cable hooked up to it. Just move it by hand.

 

Finally fixed the problem. My setup is as such; 94 LT1, 94 LT1 throttle cable, 89 Chassis, 89 Pedals.

I made an adapter to mount the throttle cable housing on the firewall. Stock 89 hole was too big. The 89 pedals connect with the LT1 cable, but the angle of the pedal to cable hole was off enough to only open the TB up about 80%. I took the pedal out of the car, rebent the pedal/cable hole angle and reinstalled. Its perfect now!

Thanks for your help guys! The car is significantly faster and this has also fixed the uncontrolability I was experiencing. I guess what was happening was I had to push the pedal down until it pulled up the slack in the cable, and then it would only open up 80%'ish. Don't know if its a general problem, or just the pedal set I installed.

 

Best thing, get a '91-'92 TPI cable, it will have the correct ends for it to work with the TB and not using any adapters.