Idle Problem Solved (98 Passport)

Over the past couple months the idle problem on my '98 Passport (3.2L V6, 2wd, 74K miles) has progressively gotten worse. At startup, it would often idle just fine, but too many times it would either idle at 1400-1500 rpms or immediately die after turning over (unless I gave it gas. As soon as I'd left off the gas pedal, it would die).

So last week I did a web search and found this site as well as the automotivehelper.com site and found that the inconsistent idle problem is a common one for these vehicles. Most theorized the culprit as an intake manifold gasket leak. I had my intake manifold gaskets changed (due to leaks) last August. The idle problem manifested itself this summer. Essentially, I ruled out the intake manifold gaskets as the cause of the idle problem.

I called a local Isuzu dealer and spoke to a service manager who said the culprit was probably due to a faulty power steering switch. He recommended that I disconnect the switch that comes off the power steering fluid reservoir. I did, but the idle problem persisted. The power steering switch has since been re-connected.

The Isuze dealer didn't think the idle problem was caused by a bad fuel pressure regulator. He said he's never had one go bad and thus has never changed one out.

So on Friday night I took off the idle air control valve, cleaned it with carbureuter cleaner, and re-installed it. I've since started and driven the vehicle many times since then without the idle problems at startup. I'm no expert (I'm actually knocking on wood hoping the problem doesn't re-occur), but I wanted to share this to give those with the same problem a viable, easy, and inexpensive way to go through the process of elimination for idle problems.

Now, my next tasks will be to work on a couple other problems that seem to be common with these vehicles: faulty in-tank gas gauge (dash gauge shows Empty when at least 6 gallons remain in the tank) and the rattle under the passenger side (rattling heat shield?).

SAP

where is this located?

idle air control valve

Souds like a good thing to spray out every couple of years.

(Just realized after posting this that I refer to the part in question as the AICV--air idle control valve. To avoid confusion, it means the same as IACV--idle air control valve.)

Amigo, the AICV is located on top the engine to the left (passenger side) of where the air intake hose meets the engine. It's a relatively small black valve that has an electrical connection going into it. Disconnect the electric, and then use a torx screwdriver to remove the two screws that hold the AICV into the aluminum. Pull the AICV straight out. There's an orange O ring that'll you'll not want to lose that seals the valve to the aluminum fitting.

My AICV was carboned up bigtime but it cleaned up well.

This evening I'll try to remember to take a photo of the installed IACV and post it up here.

If you happen to own a Haynes Manual you can see a photo of the IACV and it's location.

SAP

Hi, Iam new here. Mine is rodeo 99, I have similiar problem, some said that is the intake MG but before I go there I want to try other posibility first. Did you put the picture yet? Because I don't know where's mine(iacv) is. Thank in advance..

Thanks for the info!! I think you saved my a lot of time and money in troubleshooting. I too had the same symptoms as yours at startup. I searched this helpful forum and tried several things; cleaned the EGR vlv/ppg & PCV vlv, reset the ECM and also changed out my fuel filter - all which didn't solve my problem. A quick removal of the AICV and cleaning with some carb cleaner solved it right away. Thanks again!

Ben

:banghead: Yeah... luck for you!! Not mine, I found and cleaned it but none changed. Btw, maybe somebody can help!!!!! : :screwy:
My first thing I did is cleaning EGR but after that away worst than before(maybe I broke the O2 or...etc), changed battery no luck, cleaned IAC ..same thing , went to autozone it said Po304 misfire #4,...I explained it again my car problem: There was a little bit idle problem(the engine never stall(dead) but after I cleaned the egr the idle like crazy almost stop sign while I push the brake pedal the RPM goes to 0-100 then normal, some time "dead" this thing happend when the engine is warm/hot, Iam the second owner of this car, the previous owner only used this car about once a year that's why now only 23K on it! I did egr cleaned twice one with engine running then not running but :frown: I saw some suggestion go to IMG bad but for me I will put that the last choice because mine is '99 no more warranties for it?? any help?????? :screwy: :screwy: