Throttle position sensor question

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Geren8509
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Throttle position sensor question

Postby Geren8509 » Sun Apr 14, 2019 12:47 am

I replaced my tps, and tried adjusting it to get the idle right, but when i start it when its cold, it revs to 2,000 and slowly drops to 1500. Then when its warm, it idles at about 900 in park. Is there a tps relearn for a 98 pathfinder? 3.3l.


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smj999smj
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Postby smj999smj » Fri Apr 19, 2019 9:05 pm

There is a very specific adjustment procedure for the TPS. You'll need feeler gauges and an ohmmeter to properly adjust it and then, after the adjustment, you'll need to relearn the closed throttle position setting. There was a TSB on the procedure and it should be in the factory service manual, as well, in the Engine Control (EC) section. Nico Club's site has free Nissan FSM's available and NissanHelp.com has the individual sections at their site in the "knowledge base." You'll have to register to access it. Both have TSB's as well.

Heavy hitter
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Postby Heavy hitter » Mon May 20, 2019 9:17 am

what did you set it to? Should be about .5 volts with engine warm, key in on position, engine off

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smj999smj
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Postby smj999smj » Thu May 23, 2019 12:49 am

Heavy hitter wrote:what did you set it to? Should be about .5 volts with engine warm, key in on position, engine off
Usually, they sit around 0.42-0.44 volts, but you just can't go by that. It's not a TPS with a hard setting like they used in the ol' VG30 engines, rather, it has a learned setting similar to Fords of the era. You need to adjust it as per the TSB or the updated adjustment procedure (that came out around 1998, if I remember correctly?). That means breaking out the feeler gauges and multimeter, setting it to the spec and relearning the closed throttle position.

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Postby Heavy hitter » Thu May 23, 2019 8:43 am

That’s what the fsm says....but there was also something put out by Nissan that I saw awhile back that said the r50 tps should be at .5 volts and it worked out perfectly for me to adjust mine to that. Isles rock steady at 756 rpm

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Postby Heavy hitter » Thu May 23, 2019 8:49 am

1) adjust the sensor closed throttle voltage to .51 +-1v or desired voltage(Key on Engine off) (Backbrope center pin for signal on harness using chassis for ground.) 2) start the engine with the TPS plugged in......let it warm up at high idle for a couple minutes 3) Turn off the engine.....wait 5 seconds.....disconnect the TPS and restart engine with TPS unplugged. 4)let engine idle for 15-20 seconds and then plug in the TPS while the engine is running. 5)wait for 1-3 minutes.......the idle WILL drop to normal(assuming base idle is set correctly prior to starting this procedure)..........If the idle does not drop.....repeat this procedure over again and it will work.
Clean the throttle body before doing this and also do the idle volume learn after cleaning the TB

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smj999smj
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Postby smj999smj » Thu May 23, 2019 9:44 am

Here's a link to the TSB. Do what you want:

http://lyberty.com/car/Maxima_A32_docs/ ... 9-053b.pdf


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