maxinout93

trying to reset my throttle position sensor
can't figure out which setting to put the multimeter on or where the red and black wires on it plug into. Ive searched how to check it but its not enough details as to how to actually do it.its a 95 auto.

andrewmac

iTrader: (2)

What do you mean by reset? Idle relearn procedure or just how to adjust the sensor to proper positioning?

For proper positioning you just unplug it and then test the resistance. I'm not sure which pins it is. It's definitely the middle one and then either the top or bottom. It's hard to say because I usually work on 5th gens and the orientation of the sensor is different. It's vertical on 5th gens, appears to be horizontal on the 4th gens.

Regardless, set your ohm meter to 1Ω and look for a resistance between two of the pins. When the throttle is fully closed you should be getting 0.5Ω and when it's fully open you should be getting 0.4Ω. I usually just take a thin piece of cardboard to hold it open slightly then adjust the sensor until the ohm meter reads 0.5Ω

For more information on this check the Field Service Manual (FSM): http://www.nicoclub.com/FSM/maxima/1995/ Specifically the EC section on page 165/166. Idle relearn procedure is available in the manual as well.

jholley

iTrader: (13)

NTB99-053b

Rob_0126

I just adjusted mine without a feeler gauge.(follow the fsm if your in doubt if this will work)

- (Warm the Engine up First)
- Then put an ohm meter on pins 2 and 3(see the posted FSM), and check the ohms while the throttle is completely closed. (cant remember which one to put ground on, just swap them if it reads close to '0' )

The reading was 550 ohms on mine(I installed a BWD rebuilt TPS a few years ago).

So I adjusted the tps to as close to 500 ohms as possible(507-511 was my final reading):

- By loosening the 2 hold down screws (just loosen, dont remove so you will have some resistance while you adjust)
- and turn the body of the TPS(slightly) til the gauge reads as close to correct as possible.(Id buy some wires with clips on each end so you can clip to the multimeter prods then to the pins on the tps and watch the reading as you adjust)

Rough Illustration Below of both pin connectors on TPS(i know its terrible):

(Throttle Body Side)
[ - - - ] [ - - - ] (2 connector plugs on top of the TPS)
..............1 2 3 (pins)

- Then tighten both screws down, one at a time, while watching the reading on the multimeter, so the adjustment doesnt change.
- Then hook all the unplugged connectors/hoses that you moved to do the adjustment.
(My WOT reading was 4250 ohms)(TB wide open)

Now, the tranny seems to shift properly when turning a corner and the car has much more low end on feather throttle.

Do note though, I did a few more things, which Im not sure had any effect on this.
I drizzled some MAF sensor cleaner on the MAF, to clean it up a bit.
Also, I grounded one of the injector ground wires to the firewall, using some grounding wire(8 gauge).

I just did a run around the block. I will give more info on this tomorrow when I goto town to see if this did indeed change.

maxinout93

the issue I'm having is when I move the tps forward the car idles up too high, between 1500 and 1700 rpms. I removed it to swap it with another tps, and I guess that's why I'm having this issue now.

Rob_0126

You dont run the engine to set it. You have to unplug the connector on the right(the one closest to the passenger side of the car) to test the pins.

btw, the tps is very sensitive to adjusting. Just a hair movement can throw it way off. This is why moving it while the car is running will do what you said it's doing, idle wise, and among other things.

Hook the multimeter to the pins(2 & 3 in the diagram of the FSM), and move it and you will see what I mean.

Btw, unhook the negative terminal of the battery before messing with any electronics on the car, for the safety of your wallet.

ADD: Here is a writeup on it too.
http://vbxmaxima.8m.com/tps.html

maxinout93

alright thanks guys I think I've got it right this time she's riding like normal this time.