Qcsfinest280z Posted February 27, 2014 Share Posted February 27, 2014 The TPS is getting harder to find locally. Been to a few parts stores and they cant even order it. Even Rock Auto cant order it... smh. Finally got the car started but it dies out when I rev and idles horrible. When i unplug it, it runs a little better and revs but its still not right. Quote Link to comment Share on other sites More sharing options...
z240 Posted February 27, 2014 Share Posted February 27, 2014 The TPS operation is dead simple. It's trivial to check with a multi-meter. The FSM has the proceedure. xenons30.com for the FSM download. Quote Link to comment Share on other sites More sharing options...
cgsheen Posted February 27, 2014 Share Posted February 27, 2014 Or http://www.nicoclub.com/datsun-service-manuals ... Many people with early EFI Z-Cars are under the mistaken impression that it's really a "position" sensor - like new cars. All it actually tells the ECU is if the throttle is ON or OFF Idle and in some cases if it's Wide Open (WOT). No other position is sensed. On the turbo motors, it's just ON or OFF throttle - there's not even a WOT... Quote Link to comment Share on other sites More sharing options...
Phantom Posted February 28, 2014 Share Posted February 28, 2014 new one $90 at www.thezstore.com Quote Link to comment Share on other sites More sharing options...
superlen Posted March 1, 2014 Share Posted March 1, 2014 The running conditions you state are not completely consistent with just a misadjusted or bad TPS. Definitely test yours before buying a new one and assuming that it will fix your problem. You can pop the cover off of it and watch the contact work as you move the linkage. There are basically two switches in the TPS. At idle, one is made, the other open. At WOT the opposite of course. When the throttle is inbetween those two extremes, NEITHER of the switches should be made. It's not uncommon to have to adjust the springs/contact arms in there with a pair of needle nose to get them to function correctly. BTW, when you unplug your TPS, the ECU simply thinks that the engine is NOT idling and it will turn off it's Idle enrichment. At Idle the ECU richens the mixture a bit to promote a better more stable idle. (Leaner mixtures tend to hunt around some at idle). There is also a slight spike in mixture right when you unplug the sensor while it's running. This is the ECU thinking you just came off idle and it wants to make sure the bit of extra air as you come off of idle doesn't lean you out a bit. It's time delayed so you only get this enrichment for a short duration. I dont know exactly how much extra fuel it delivers or how long the "short duration " is. So if you say the engine runs a bit better when you unplug your TPS, it's an indication that you're running rich now. My guess it that you're running quite rich for any number of common Z L-Jet reasons. Len Quote Link to comment Share on other sites More sharing options...
NewZed Posted March 1, 2014 Share Posted March 1, 2014 An addendum to superlen's advice - test at the ECU connector. See through the wires of the ECU. While you're there, do all of the other tests in the Engine Fuel chapter.. Quote Link to comment Share on other sites More sharing options...
Tony D Posted March 1, 2014 Share Posted March 1, 2014 BMWs and early VWs used a pair of micro switches on brackets an oblong lookin cam (or flat) to trigger the switches. Can't find one? You can make one pretty easily! Quote Link to comment Share on other sites More sharing options...
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