TPS adjustment

[Smilez]

I've search and can't find how to adjust the TPS sensor. I've got high idle and the PFC sensor check is showing the TPS at 0.35V at idle. it should be 0.5V. How do I adjust the voltage?

[amnash]

the TPS can a idle contact pin. not sure which one. i think there's 3 wires. one will be ground i think the other is your tps voltage and the other is idle contact. you could set the tps voltage to spec(check FSM) or you can just find the idle contact and turn the tps until it gets a signal and then stop. then check it by opening the throttle body by hand, the second you move the TB the voltage should disappear and then when closed it should come back. you can do all this with engine off and a simple multimeter

[amnash]

ya, page EN-373 of skyline engine fsm. closed its aprox 0.5v. should check the full range on TB too with engine off, just ignition power on. should raise smoothly from 0.5v to 4v

[Skym]

Undo 2x screws on TPS and rotate. The voltage should change on handcontroller. When at correct voltage, retighten 2x screws on TPS.

With Nistune tuning software or on Nissan's Consult (handheld diagnostic computer) it has a button type of thing that light's up when touching idle contact inside TPS. Idle contact pin is somewhere around 0.48V from memory. The problem with having idle contact pin, is it can bend over time (design fault with R32 TPS), so TPS has to be replaced when they bend (idle, WOT contacts) and it's not just that, the circuit board track wears out as well. By the sounds of it bent idle contact is the fault with TPS on your engine, as at 0.35V it probably would be bent.

[Smilez]

so I have to replace the TPS?

Undo 2x screws on TPS and rotate. The voltage should change on handcontroller. When at correct voltage, retighten 2x screws on TPS.

With Nistune tuning software or on Nissan's Consult (handheld diagnostic computer) it has a button type of thing that light's up when touching idle contact inside TPS. Idle contact pin is somewhere around 0.48V from memory. The problem with having idle contact pin, is it can bend over time (design fault with R32 TPS), so TPS has to be replaced when they bend (idle, WOT contacts) and it's not just that, the circuit board track wears out as well. By the sounds of it bent idle contact is the fault with TPS on your engine, as at 0.35V it probably would be bent.

[Smilez]

got the TPS to 0.5v and then re-did the idle learn. afr are sitting nicely at around 15. however the high idle is still there, hovering around 1200rpm. I did a smoke test a little while ago and there was a VERY small vac leak around the #2 throttlebody where it meets the block. could that cause the high idle?

[Skym]

Airleak near hose that goes to AACV, IACV can cause idle to rise, stay there (rpm can rise if engine is running leaner). I think so can adjusting TPS, which might make engine run leaner or richer, depending on how it's adjusted. Incorrectly adjusted AACV is another (screw on it).

If voltage is reading low at WOT (put foot to floor with engine off, but ignition on, so supplies voltage to ECU and note peak voltage, I think below 4V? if faulty) or idle contact pin is not at correct voltage, replace TPS. Idle contact part can be tested by driving car and putting aircon, light's, etc on (load engine up) and stop quickly (back of throttle). If ECU kicks rpm up and engine recovers without problems, idles higher (like it should with aircon, etc on), then idle contact should be ok. Can try it on hill where there's more load on engine to double check.

[Dragon Humper]

There is a screw and lock nut on the throttle linkage right beside where the cable attaches, try backing that off. You never know, someone might have been monkeying with that. With the PFC its really easy to set the idle mode, there is a sensor check screen for switches, idle is there, adjust the TPS untill the switch turns on....done. If you make it really sensative, the slightest throttle movement makes the idle switch turn off, there should be no hesitation whatsoever at tip-in.


Jon.

[Smilez]

with the AAC unplugged it idles REALLY lean, off my AEM widebands gauge. however, it is at 900rpm like the manual says. plug it in and it goes back up to 1200rpm and normal AFR. no idea where to look next, could the VERY small vac leak cause a 300rpm jump? should I even worry about the 300rpm? idle is perfect otherwise.

[Smilez]

black dot means "on" in the sensor check area, right? idle switch won't turn on, even when I back the screw off. any ideas?

There is a screw and lock nut on the throttle linkage right beside where the cable attaches, try backing that off. You never know, someone might have been monkeying with that. With the PFC its really easy to set the idle mode, there is a sensor check screen for switches, idle is there, adjust the TPS untill the switch turns on....done. If you make it really sensative, the slightest throttle movement makes the idle switch turn off, there should be no hesitation whatsoever at tip-in.


Jon.

[Dragon Humper]

Yes, black dot means on. If it's not lighting up then that's your issue. Loosen off the bolts for the TPS and adjust that untill it lights up, then engine can be off. You can also double check the voltage on the commander as well. Once you get that set up then do the procedure for setting the idle with the AAC. I would also adjust the throttle blades so that the AAC isn't compensating at all at full operating temp and your idle is 950rpm.

I had to fiddle with mine for a long time before I got it right. The factory settings were all wrong with the little cams I have got, they must be even worse with larger cams. It's always best to have the throttle blades giving you the idle you want, not the AAC, even stock. The awesome part about the PFC is that you can make sure the computer is happy with how you have it set up. My tip-in is super crisp, no hesitation at all.



Jon.

[Smilez]

If I move the TPS back and forth and the light won't come on, that most likely means the TPS is pooched?

[Skym]

Idle contact is probably bent or throttleplates are adjusted wrong. Opened up TPS on my car and bent idle, WOT contacts, but TPS was stuffed on circuit board. It worked, but still didn't fix problem with TPS. Only option is to replace TPS.

When TPS is stuffed, the WOT, range voltage drops. I was wrong about 0.48V, it was 0.44V.

This is from my car (Nissan Consult printout) :-

Incorrect TPS voltages (TPS failure) -

DEPRESSED : 3.60V
RELEASED : 0.42V
RANGE : 3.18V
SPEC : MORE3.0V

Correct TPS voltages -

DEPRESSED : 4.02V
RELEASED : 0.44V
RANGE : 3.58V
SPEC : MORE3.0V

The 0.02 for WOT is higher than the 4V it should be and that TPS failed later on.

[Smilez]

Yeah, after I set the TPS to 0.5V my WOT is now 4.16V so the range is off. I've got another TPS available, going to change it tomorrow and go from there.

Thanks for all the help, you guys rock!

[cobrAA]

If you buy a new tps sensor, do you need to adjust it or should e on spec straight out of the box ?