I have a 2005 Express 3500 with a cable-activated Throttle Body...not a control by wire, which they started doing in 2006.
I want to replace the IAC valve and all I can find is cable connectors but not the valve. I did come across one that looks exactly like mine, Delphi #CV10011 and was on Amazon but they will not ship it to CA for some reason.
Very frustrated! Any ideas? I know some of these IACs are expensive.

 

Hey man just read your posts

I couldn’t find a IAC for my van, 2004 chevy express with 6.0 LQ4 w/ CABLE TB

Every time I found one, soon as I enter my van details it would say not compatible 🤷🏻‍♂️

I finally found a IAC that worked flawlessly, I’m already 700 miles with zero idle problems

here is the part number

Delphi - CV10012

I also had to replace the Throttle position sensor

the idle was a instant improvement after these parts were changed BUT it still wasn’t perfect

it took almost 300 miles before the idle and throttle felt 100%

Van currently is driving great with 342k original miles

 

Sounds like something to try. I hate taking the throttle body out to get the IAC replaced because of the two hoses that go to the back of the Throttle body. They help heat the body with water from the engine.
I bet the reason it took so long for the idle to feel normal is that the computer needed to adjust to the new parts. I hate these computers. Give me the old stuff that just worked! I know it is all about the air quality on our planet, but when will we start using hydrogen power engines that have no emission problems.

 

How did you find the correct part? I looked for that number and it always says not compatible just like you found. When entering the engine type no one lists the 2004 chevy express with 6.0 LQ4 w/ CABLE TB. Mine is a 2005 but probably the same engine.

 

My problem is when I try to start cold it does not start and just dies unless I apply a bit of throttle with the gas pedal. It still never does the fast idle like 1500 rpm. After it finally warms up it only idles around 500 rpm and is not smooth and steady. I will drive OK with good acceleration and does not stall at idle. I looked all over the place for vacuum leaks but could not find any. The PVC valve is part of the valve cover so I left that alone. Everything points to a bad IAC but not sure which part to buy, and they are not cheap. The one you said works is $137, and others are about $75.
No one on the internet seems to know which works for this engine and they all say these engines are all controlled by a computer and no manual cable.

 

I did find that part number on rockauto and ordered it. Hopefully it will work. I do not think I need the Position Sensor as it seems fine but that is easy to find and replace. With the IAC I have to remove the TB or drive myself crazy getting the back screw in place for the IAC.

 

If you’re pulling the throttle body, I highly recommend replacing the TPS at the same time. I initially only swapped out the IAC valve, which significantly improved idle behavior, but I was still experiencing inconsistent throttle response and idle anomalies.



It felt as if the vehicle had cruise control engaged—despite not being equipped with cruise control.



After replacing the TPS, the issue noticeably improved.



The primary issue was a high idle on both cold and warm starts. On ignition, RPMs would spike to around 2300 before gradually dropping. In most cases, idle would settle between 1000–1200 RPM, rather than the expected 650–750. On rare occasions, the engine would crank with a very low idle and nearly stall, requiring throttle input to keep it running.



What made diagnosis difficult was how intermittent the issue was. Every time I brought it to a mechanic, the vehicle would run flawlessly—making it hard to replicate the symptoms. More than once, I was told, “everything seems normal.”



I also replaced the throttle body gasket while I had it off, it’s a $10 part and worth doing preventatively.



Be careful when removing the (3) 10mm nuts securing the throttle body. I accidentally dropped one and had to purchase an entire replacement hardware kit ($25) just to get a matching nut.



As for the IAC valve, sourcing the correct part was a challenge. I ended up identifying compatible models by cross-referencing vehicles that used the same engine (6.0L LQ4) with a cable-operated throttle body. It took some digging, but that’s how I eventually found the correct IAC that worked for my setup

 

dang that’s a sweet deal on rockauto $68 bucks is amazing… I bought mine at AutoZone $138

 

Yes Rockauto can be a life safer. I remove the TB since it makes it so much easier to replace the IAC because of where the rear screw is located. If I need to replace the TPS I can do that with the TB in place. I regularly have cleaned the TB since this is a express 3500 under a class C RV so it does not get run often. I try to take it out for a run around the area once a month but with age comes less money, wife who passed in 2022 and generally no place special to go to.
I just want it to run like it used to. I was going to figure a way to give it 12 volts at the IAC to see if it moved but that might be nuts as I am sure it is closed and the only air the engine gets is when the throttle is manually opened.
Thanks again for all the help. Hopefully this IAC will do the trick. Even after the engine is warm the idle is not smooth and below the normal 750 rpm. No Codes either. TPS may just need a reset. I have never found a vacuum leak so not sure what could cause that. I know the PVC valve is built into the valve cover so cleaning that is a problem but according to what I find on the internet it is only a piece with a small hole in the bottom that allow any blow-by to get pulled into the engine. Always something!!

 

One other thing I forgot is that I unhooked the battery for a couple of days and I know that clears all the computer settings. Like I said before, once it is warmed up it runs fine except for the low idle and a slight up and down of the rpm's. Always passes CA smog tests since the engine is hot when they run through the process.
I just hope this will help and I also will need to do a drive cycle to prep for smog test...that is always a chore and lots of gas.