How to adjust TPS

[foxspy]

Hey guys,

I am knew to this board, and I do not have a turbo buick, but i am a big fan of them. On my Speed-Pro computer the TPS reads 75% WOT, it did goto 83%, but idle was at 13%. I opened the throttle blades and put the TPS to 4% at idle, but now it only goes to 75% WOT. What can I do to fix this problem???

Thanks,

 

[bobc455]

Are the throttle blades opening all the way? Since the system works off of manifold pressure and not TPS, it shouldn't be crucial that you read 85% (or whatever) at WOT. If the throttle blades are not all the way open, check for throttle linkage problems, floor mats preventing you from reaching WOT, etc.

If there is some reason you need the value to reach a full 85%, then you should 1) check to make sure the TPS is responding correctly (by moving the TPS without the throttle blades) and then 2) you'll probably have to putz around with the mechanical side of your TPS (adjustment screws, etc., depending on how its mounted). But, like I said before, this probably won't matter for you and 75% should be okay for WOT.

If there is some other problem, then you can check voltage across the TPS- should be about 0.45 volts at idle and about 4.6 volts at WOT (there will be variation for every car for each of those numbers).

-Bob Cunningham
1969 Buick Special Deluxe w/ 455
bobc@gnttype.org

 

[foxspy]

My throttle blades are opening all the way. The TPS did read 83% at WOT, but idle was at 13%TPS, I adjusted that down to 4% and now it goes to 75% at WOT. But yes, the throttle blades do open all the way.

 

[RickWI]

Yo want TPS to be set at 12%-13% @ idle. Setting at 4% is too low and that is why it only goes up to 75%.

 

[mosk]

Hey Rick (or anyone else),

I've got a related TPS question. I have a TB from a Ford Explorer on my turbocharged Toyota truck. The TPS on this TB is essentially fixed -- the TPS mounting holes are just round holes, not slotted in any way, so there really isn't any adjustment possible (other than via the throttle plate).

According to the SP, my TPS reads 19% when fully closed, and 93% at WOT. My understanding is that as long as I can get the TPS to read above 80% (to allow the ECU to enter "flood clear" mode), these numbers are OK.

Comments? I can probably cut some slots in the TPS holes, or get at the holes with a Dremel tool to get the TPS to read a little lower when the throttle is closed, but I'd rather not if I don't have to.

TIA,

Jeff

 

[RickWI]

I think all you will have to make sure of is that your base maps you begin to tune off of are set up to assume 19% is the idle setting. The A/E vs TPS table is one that will need to be changed to reflect the non standard setting. Based on what I know now I would not go through the trouble of making it adjustable.

 

[55Belair]

To adjust the TPS you will need a digital voltmeter and a torx bit to fit the bolts on the tps.

open the wiring connector clip on the back of the tps plug while it is still connected to the tps. stick the probes of your voltmeter in the wiring connector for wires "A" and "B" they are marked on the plug. turn the ignition key to the on position but do not start the car. look at your voltmeter. it should read .45-.55 volts at idle. If it does not, then loosen the tps torx screws and move the tps until it does match that range. Mine is set at .50. keep the probes in the wires while you are tightening the screws. it will try to move.
Once you have that, then remove the probes, fasten the wire retaining clip back on the plug. turn the ignition off then turn it back on and start the car.
go to your dashboard and look for your tps info. .50 should be around 10% or so. Then go to your idle section, Idle parameters and reset your max % for idle setting to 11-13.

 

[Craig Smith]

Everybody put your tools away!!!

Your TPS reading really shouldn't concern you at all. As mentioned in a previous post, the ECU will enter "clear flood" mode above 80% TPS while cranking. Other than that, the number is unimportant as far as tuning is concerned.

As far as trying to achieve a lower reading at an idle, you honestly do not need to do this. It will make NO difference in how the car runs. There are 2 places in the software that you should pay attention to with respect to throttle position:

1. Go to idle speed, and then go to idle parameters. There is a value called "Max TPS for idle" here. Set this value to 1 higher than your TPS reading at an idle. When your TPS reading is BELOW this value, the ECU will attempt to regulate idle speed with both he IAC motor and the Timing Trim screen. When the TPS reading is ABOVE this value, the IAC motor will be positioned according the Throttle Follower table and the Timing Trim screen will not be used.

2. Go to VE/Fuel, and then go to AE Fuel vs. TPS position. Set this screen so that you have 100% enrichment at an idle, and ramp it down at about a 45 degree angle from there. That should be a good starting point - you may have to tweek it a little but that general shape is what you want.


No need to worry about voltages, etc.

Craig