TPS idle switch

[alexanderp]

What is supposed to happen when the TPS idle switch is disconnected while the engine is running?

Can't find an answer anywhere.

[KennyJ]

the ecu wil alter the ignition timing (advance) , ignition is retarded in idle for stable idle

[alexanderp]

So technically the idle would increase if the idle switch is disconnected (timing advance=higher idle)?

I have problems with high idle, and when I disconnect the idle switch nothing happens. I have tested it with a multimeter and the TPS is fine, but the wiring has been tampered with and might be faulty.

[KennyJ]

correct ,

if you wanna check with the meter measure what the ecu reads , so at the ecu connector

[alexanderp]

Which pins should I measure at the ecu harness? From what I read it's 54 and 57, correct?

[alexanderp]

Nvm solved it. Wiring to the idle switch was shorting out AND in the wrong order (power to ground and ground to power..).

Anyway, ran a on/off switch diagnostics and TPS is working again. It fixed most of the problem med idle still jumps a tiny bit when engine gets warm. Triedunplugging IACV to set idle but nothing happend. I did test the IACV earlier and it was working fine. Will try measuring if wiring is OK tomorrow.

[Rochester]

Modest thread hijack if I may, something I was unaware of until found out by accident, replacing my original tps; there are different types for manual vs. auto. Anyone doing an auto to manual swap may want to change the tps too. That said I have no idea what the functional difference is, and if keeping the auto ecu it may be better to keep the auto tps ? Skyshack, any words of wisdom perhaps ?

New tps certainly did a lot to pep things up and all is very well...

[skyshack]

Auto has a 2nd set of contacts for wide open throttle. This is not the kickdown switch. It connects the Auto control unit to the ECU. The ECU section of the manual says nothing and the Auto control section just gives observed voltages. Page AT-45 also gives little detail about function except how to check it.

I suspect it tells the ECU that the Auto box is going to kickdown and to remove power (ignition?) so the Autobox clutches don't burn out. A crude version of modern rpm matching. It would have to be monitored on rolling road to detect this function. Hence the only test is if it connects the Auto control to the ECU when throttle is wide open, then it's good.

[Zeldoz]

I have an RB in my s14 and have had idle issues of late. Although they seem to be (ok) for now.

But it's interesting as the engine was an auto, now a manual. With a manual ecu, iv never changed the TPS. I paid for the looms to be spliced together, but have no idea if it's been wired correctly for the auto TPS. I did say it was an auto though.

I just wonder if this may have contributed to my issues at all..

[skyshack]

Unplug the auto control box, then it won't matter how it was wired.