1987 Z24i TPS. Truck does not idle/run properly. Hesitant on acceleration and dies when idle. Going thru all electrical wires/connectors. See question below
Posted Apr 28, 2019, 7:11 PM UTC
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For those curious: Brand new fuel filter,plugs, wires, cap, full tune up. The day I clean the MAF and replace all vacuum lines is the day she quit running.
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Picked her up for 100 bucks. Shes a little dirty. Anyways, my question is this: is there supposed to be 2 or 3 wires coming from the TPS? The sensor itself has 3 prongs, but the connector has only 2 wires. Also, the hole in the connector (where the 3rd wire could go through) was exposed and allowed alot of dirt to sit on the sensor and its prongs.
edited, didn't see the pigtail was actually connected, making this TPS a dual hookup model (those are usually dual socket); https://ww2.justanswer.com/uploads/ProNissan/2010-03-17_195339_Throttle_position_sensor--_closed_throttle_switch.jpg
the white and pink wires are literally visible in the image, so you have the two connector version, with the pigtail. the two that are clean in the socket in the image are a switch pair, the dirty one is the other side of a switch, center common between them. you should get as close to 0 ohms as possible with the throttle butterflies either open fully or closed fully. and the readings should invert, so pin 3 in theory would read several hundred to thousand ohms, while pin one should read near 0 with the butterfly all the way open. with it closed 3 should read 0 and vice versa. it might be the other way around i don't have one here to test.
pigtail is 3 wires, white is reference/signal, pink+black is voltage from ecu/ecm and black is ground. with a meter, you should get ~5v from the pink and black wires with the key on on/run.
you should also get a fixed reading between the outer pins on the pigtail connector, but i don't know where in the fsm that ohm reading is listed. figure hmmm.. around 4k? when engine is off, connector is off the tps, and throttle butterfly is fully closed.
should see a change in voltage from 0.4v to 0.6v on white and black with everything hooked up and the key on, and you manually move the butterfly (with engine off)
I appreciate the help! Ironically I had to get stitches on my index finger immediately after I read your reply. I wont be able to work on it for a few days. I did manage to pick up a new wire harness for the TPS. So now I just need to find where that 3rd wire got off to so I can splice it
no 3rd wire, i updated my reply, you can just fill it with hotglue to keep the dirt out and you should be fine. and possibly return the pigtail.
once you get up and going again and can work on it, i'd test function of the tps and maf sensors and go from there. if those are good i'd look at the idle control setup. if those all test good i'd start testing the harness itself, and possibly the ground at the cab above the engine (its known to get messed up after a while on some trucks)
Hey, bisonmp, just a quick heads-up:
alot is actually spelled a lot. You can remember it by it is one lot, 'a lot'.
Have a nice day!
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Fuel and spark are good. Which leads me to either electrical/sensor or oxygen.