Throttle Position Sensor or Injector Pump

[Homebrew]

Hello All.
Been through as many discussions as I can find and nothing that resembles this issue. I have a ZD30 direct injection Nissan Patrol. Started it, reversed it out of the garage went to go forward and bang, straight to limp mode. Checked the fault code with ECU talk. Indicated that it was Throttle Positional Sensor. OK, replaced the sensor making sure the OHMS setting was at .5 as per manual. Disconnected the battery overnight and refitted the peddle. The engine starts no worries. However, engine goes into limp mode once the engine revs above 1600 rpm. If I pump the accelerator as though it's a petrol engine trying to start cold, it will rev right up to 3 to 4000 rpm. Only problem is it will only run for a few seconds and cut out as though I turned it off. If I start it again, it starts perfectly but still won't go past 1600 rpm. When it stops the ECU Talk indicates that it is the TPS again. Any help would be appreciated.
Regards homebrew.

[mudnut]

Check there isn't any hoses or other wires off under the bonnet or any moisture in any modules.

[mudski]

Was it a brand new TPS you used as a replacement?

[Homebrew]

Thanks mudnut......Thinking about it, I did wash the car the afternoon before.

[Homebrew]

Yep, reportedly. Bought from Ebay. The new part does give the correct OHM reading when tested. The original just OL on millimeter screen.
Thanks though.

[mudski]

Which store? I used to run and import Genuine Nissan parts on eBay myself. Did so very successfully for six years. I know of a few stores selling “Genuine” parts when in fact they were Chinese copies.


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[jff45]

If you have an Ecutalk, you can see on the screen if the TPS is working correctly. It would also have confirmed if the original really needed replacing.

[Homebrew]

mudski, The name of the Ebay store is goodstate. Interested to learn your opinion.

[mudski]

Yeah it will be genuine.

Those pricks started a big price war no eBay when they first opened up. There was pretty much me, Patrol a Part and a couple of others on there, we all would set our prices pretty much on par with each other, it worked well, me and and two other stores used to swap or sell parts to each other at cost if they, or I, had a customer after something in particular which we didn't have.
Then this mob came along and was undercutting so hard I dont even know how they were making money. Now, every man and his dog is on there just doing the same thing, undercutting each other. I remember having to spend a few hours a day just sitting there revising prices by 1 or 2 cents, yes that little, just so I could sell something. Only to see a day or two later this mob had just lowered their prices again by 1 or 2 cents. and when you have over 1000 items to revise, it gets on your nerves a little. It was out of control.

But I suppose its good for the consumer though, prices are cheap and not even worth these days from buying from overseas now. Just aswell I sold my business when I did. As I know the chap who bought it, is not doing real well with it now. And he paid bought the business with cash too which was even better.

[Homebrew]

Well, that's the only bit of good news I've had in this experience. The price range for the TPS was quite considerable, from $180 plus to $105. Thanks again for your reply it takes another unknown out of the equation. Cheers.

[Homebrew]

jff45 thanks for your post. It has become very confusing. After reading your reply I decided to rechecked for the umteenth time the old TPS with a multi meter. It has now found life again after about a week of death. I reinstalled it on a temporary basis into the Patrol and tested it with the ECU Talk. Again it showed life, although the readings are down compared to the new one. I'll change it back again and start looking further under the bonnet.

[Homebrew]

Found the problem. It was the small switch screwed closest to the accelerator arm and has the wiring terminal above the TPS. I checked the resistance and found it to be faulty. Unfortunately the switch isn't sold separately in Australia and had to buy a complete accelerator assembly.
Thanks to the fellas who had input.

[mudski]

Found the problem. It was the small switch screwed closest to the accelerator arm and has the wiring terminal above the TPS. I checked the resistance and found it to be faulty. Unfortunately the switch isn't sold separately in Australia and had to buy a complete accelerator assembly.
Thanks to the fellas who had input.

Nooooo I have one of those switches here!!!! You coulda had it for the cost of post!


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[mudski]

80972
Found it!


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[Sprock]

You’ve got very masculine looking hands Mudski 😉

[mudski]

You’ve got very masculine looking hands Mudski [emoji6]

Got I gotta stop drinking whiskey while in the garage. I forget I’ve done things in here. Lol I forgot that I found this part, totally...
Too late. I’m in here now, having two fingers worth....


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[Homebrew]

Well a new development with the cause of the throttle failure. I removed the micro switch and as an after thought I re tested it with a multimetre. It worked fine as per specs. No resistance with pedal up, resistance when pedal down. I then noticed that the neoprene buffer or button, similar to the one between the brake pedal and brake light switch, was stuck on the micro switch side of the assembly. It was not allowing the switch to disengage and complete the circuit. The same has happened with a few cars I've owned where the button on the brake pedal falls off and leave the brake lights on until you notice the issue or you have a flat battery. Never had one stick before.
All the time and effort........ Anyway, I won't be needing a new switch after all.