Nissan/Infiniti gurus in Denver? :wtf2:

[turdlarsen]

Greetings all, new to this great site. Recently moved to Denver and all was well until idle issues, p0507 code thrown, and now 2002 qx4 refuses to start ....all happening this weekend. Can anyone suggest a mechanic in the area? My truck sits sadly parked in the bus lane (ok on weekends) and I have to tow it somewhere before 7am tomorrow when the lane opens back up. Thanks all, cheers!

[Towncivilian]

Welcome to NICO.

I don't have a suggestion for you since I'm all the way in Florida.

Some things you should check though:

Are there any air intake leaks? Have you tried cleaning the idle air control valve?

[turdlarsen]

Hey TownC

Just moved from Florida 7 months ago. I did check for leaks, cleaned throttle body, but did not clean the valve. It was idling high and then all of a sudden, would not turn over. How do i clean it? Thanks for the response

[Towncivilian]

The IACV is held in by two Phillips head screws. Use throttle body cleaner spray to clean it, nothing else. Here is its location (in green):



You may as well clean the throttle body plate while you have the air intake tube off as well.

[turdlarsen]

thanks, will give it a shot.

[turdlarsen]

ok, attempted to remove the IACV, but my rudimentary tools were not helping and denver has decided to rain (car is stuck in bus lane soon to be a tow zone tomorrow at 7am). Yesterday, after cleaning the throttle body, I tried to do a idle adjust using the "contra" style method (ignition 3 sec off 10 sec x3 then ign 3 sec pump gas 5x wait 7 sec hold down gas pedal until cel light stops blinking) but it did not stop blinking. I maintained running engine,trans temp etc. as well. after that it would not start. Did i jack up the ecu? Battery is now disconnected....will it reset?...damnit, not really a mechanic. thanks

[Towncivilian]

After reconnecting the battery, try following the idle air volume relearned procedure on page EC-69 of the factory service manual: http://www.nicoclub.com/FSM/QX4/2002/EC.pdf

[turdlarsen]

thanks for the help, ill see what happens

[turdlarsen]

Hey Town,

Heres my update for my vehicle. Could not get the truck to start, noticed a burning smell. Had the car towed to a local mechanic. He said the IACV failed, shorted out the wiring harness but thought that the ECU would be ok despite my concerns about needing to replace both for the sake of shorting each other out. He installed IACV and mended the wiring. Now the car starts he says but idle is still all over the place because The ECU circuit was also fried. This was yesterday at $870.00. To replace through his shop with brand new factory ECU would bring total up to 2597.00. This includes 160.00 to reprogram. I will NOT proceed at this auto shop.This My question is, should I have the car towed back to my house as not to fry the new IACV? Also, does a refurbished (or the original ECU rebuilt (like avproecm.com)) really need to be reprogrammed? Thanks again for your help brother...I'm alone in a big city...left my mechanic that proved his experience and trust in Florida.

[Towncivilian]

Ouch, bad luck there. I'm pretty sure you can just disconnect the IACV harness to avoid harming the new IACV, but I'm not sure whether that would still potentially harm the wiring. A replacement ECU will require NVIS (Nissan Vehicle Immobilizer System) reprogramming; in other words, all of your car keys will need to be associated with the new ECU. I believe only a Nissan dealership can perform this reprogramming. I'd try eBay or maybe a junkyard to find a cheaper ECU.

[turdlarsen]

What about a rebuild of the old ECU? The mechanic acts like the ECU still functions but only the specific circuit is fried. Would I be able to retain its old programming with everything?

[turdlarsen]

Just called avproecm.com. He told me the ECU should not need the reprogramming. Sounded like a real knowledgeable guy...in Florida as well.

[turdlarsen]

He also mentioned that some vehicles have electronic motor mounts that he has seen short out another circuit on the ECU. Does my vehicle have these? How can I disconnect them? Thanks Town and everybody for your help

[Towncivilian]

Our vehicles do not have electric motor mounts. Repairing your current ECU will not require any reprogramming.

A replacement ECU would not require reprogramming, it just needs your car keys associated with NVIS. Sorry for unclear wording.

[turdlarsen]

thats ok, good to know...thanks!