NJ 3.0lt idling high

[hudson44]

Hey boys, its been a while. I'm having drama's trying to get my 3.0lt Paj to idle below 1100rpm. I have tried replacing both the IAC and Throttle body. The IAC tests ok and is working as it idles up with steering and A/C. I have heard of the wax pallet within the throttle body playing up and i have replaced this with another one from another engine but to no avail. (that's not to say they are both not faulty). I am thinking maybe the ECU is my next port of call? I have set the base idle screw as per factory specs and the idle air screw is wound all the way in. I have poured water over the throttle body etc and that is indicating no air leaks. Has anyone come across this before or have any suggestions?

[-Scott-]

Hey boys, its been a while. I'm having drama's trying to get my 3.0lt Paj to idle below 1100rpm. I have tried replacing both the IAC and Throttle body. The IAC tests ok and is working as it idles up with steering and A/C. I have heard of the wax pallet within the throttle body playing up and i have replaced this with another one from another engine but to no avail. (that's not to say they are both not faulty). I am thinking maybe the ECU is my next port of call? I have set the base idle screw as per factory specs and the idle air screw is wound all the way in. I have poured water over the throttle body etc and that is indicating no air leaks. Has anyone come across this before or have any suggestions?

Hi Gabe - wotcha bin up to?

Have you considered temp sensors? If the ECU thinks it's cold, would that make it idle high?

[hudson44]

Been busy Scott. Bought a new house and just had our 3rd (and last) kid. The old Paj has been a little neglected. She needs new rubber, so i'm going up from a 32" to a 33" on a 15 x 8 rim with 0 offset. Am tossing up between the KM2's and the new MTR kevlars. I want to get her back in ship shape form and get back out there again...

I think you might be on to something there. When i think about it, it has idled high since i put the new jap import motor in, and the coolant temp sensor is about the only thing i didn't use from the old motor. I have one lying around. I'll give it a try tomorrow.

[hudson44]

No good. Damn. this one really has me stumped. Anyone in Melbourne have a spare 3.0lt Ecu they can lend me to diagnose?

[hudson44]

Just an update if anyone has any ideas. I blocked off the fast idle valve on the throttle body to rule this out. I was able to set the idle at the desired RPM with more to play on the idle screw. Went for a drive and all was good. Turned it off then on again and what do ya bloody know, Idle at 1100 rpm again. If i wind the IAC motor all the way out by hand (idle at its lowest) and start the car, it will idle really low. Every time i restart, the idle creeps up until eventually it settles at 1100rpm again. I am thinking it has to be either the IAC or the ECU. Anyone got any suggestion?

[-Scott-]

Exorcism?

[NJV6]

I have read somewhere I can't remember where that a poor earth will cause a high idle, and this can be in the ECU....

Poor earth in ECU is my guess but since you didn't pay me its worthless and probably wrong

Are you able to source another ECU? I have two here that are no use to me as they are quite different to the 3.5's but they are along way from you

Here are two companies here in NZ that offer them repaired, its a pretty common thing with the ECU's

http://www.trademe.co.nz/Trade-Me-Motor ... 553608.htm" onclick="window.open(this.href);return false;

http://www.trademe.co.nz/Trade-Me-Motor ... 908093.htm" onclick="window.open(this.href);return false;

[hudson44]

Yeah i will look at getting an ECU Glen. It has a high tide mark on the circuit board from when i drowned it, so I'm thinking if its not shagged now, it will be sooner or later. Damn why haven't they invented solid particle e-mail yet so you can e-mail me an ECU over!