Mopar brand IACV

[hgeranium]

What are yalls opinions on dropping the ~$118 to get a Mopar IACV? (83503643). I can get a standard ignition one for just under $30 on Amazon (which is what I’ve done), or I can get it from O’Reilly for $80 with lifetime warranty. I’m about to be on my fourth IACV: original from PO, 2 that I have replaced myself, and 1 that comes in tomorrow.
 

The warranty would be nice but I hate the idea of still having to constantly troubleshoot idle issues and frequently replacing the part if it’s bad out of the box or goes out after a few weeks like it’s been. If I’m paying $80, I feel like I’d rather just pay an extra 30 to know that it’s a genuine Mopar and not need the warranty because I know it’ll be quality. For a crucial part like the IACV or the CPS, I feel like it’s totally worth it for peace of mind alone. 
 

But what’s y’all‘s mileage with it? I know some people get lucky with the aftermarket brands but I clearly have not been. It’s become a red herring. You install a new part assuming that it works, and when the problem persists you logically move to the next likely source, not really knowing that the new part either never worked, or only worked for a short time. The intermittentness and difficulty of testing the IACV specifically just exacerbates this problem. 

[Rex89]

I’m basically in the same boat as you right now. I got the $23 “A-Premium” brand IAC off Amazon just last week. I thought it had fixed my idle issues but either (1) I got what I paid for because it died after about 30 minutes of driving or (2) I have other electrical issues because I’m still fighting super high idle on cold startup. I thought it was a vacuum leak but I’ve addressed that and I believe it’s an electrical problem. 
 

I have yet to do cruiser’s tips related to some of these issues so I’m going to give that a try before I replace any more parts. I just unwrapped all the wiring harness from the sensors to the dipstick tube stud to clean up all that wiring. I’m also going to do the ECU connector refresh and see if any of that helps. 
 

All that to say, I don’t have experience with the premium sensors you’re asking about, but if the wiring/ECU isn’t the issue, I’ll probably have to go with the Mopar or whatever quality sensor. 

[Rex89]

Ok so I just wanted to provide an update. I went ahead and cleaned up the engine bay wiring, mainly just taking the factory splice out and creating a few new ground wires for the ECU and injectors. Knock on wood, but after doing that, it seems to be doing better. I hesitate to say it’s “fixed” until I have a few more days to test it on cold starts, but it’s promising. 
 

This is what I was working with:

 

 

 

There were 9 wires going into a splice and coming out as 2 wires. 6 of the wires were from the injector plugs, 2 from the ECU ground port (through which most of the sensors, including IAC, all ground), and 1 uninsulated wire that was coming off the knock sensor wiring. The knock sensor wiring was encased in a separate gold-looking insulation that I did not unwrap. I did put the uninsulated ground from it in one of the splices I created. Below photo shows the factory splice I cut out. 

I created new wires with 3/8” ring terminals and put them all on the dipstick tube stud. I gave each of the 2 ECU grounds their own respective wire and terminal. And I took a bundle of 3 injector plugs each and made a splice into one wire for both of those bundles. I included the knock sensor ground in one of the injector bundles. 

 

 

I forgot to get a picture of the dipstick tube stud. It’s crowded but it all fit. 

There was also this factory splice that takes the TPS, MAP, CTS, and IAT all into one. I took the tape off and the solder actually looked fine. So I just put some heat shrink around it and taped it up a little better. I forgot to take an after picture but this is what the factory tape looked like. 

 

 

Like I said, I’ve only tested it a couple times over the last few hours, but it seems to be doing better. And I still have the cheap Amazon “A-premium” IAC valve on there. So if you haven’t done so already, it can’t hurt to clean up the wiring a bit! 

[hgeranium]

21 minutes ago, Rex89 said:

Ok so I just wanted to provide an update. I went ahead and cleaned up the engine bay wiring, mainly just taking the factory splice out and creating a few new ground wires for the ECU and injectors. Knock on wood, but after doing that, it seems to be doing better. I hesitate to say it’s “fixed” until I have a few more days to test it on cold starts, but it’s promising. 
 

This is what I was working with:

 

 

 

There were 9 wires going into a splice and coming out as 2 wires. 6 of the wires were from the injector plugs, 2 from the ECU ground port (through which most of the sensors, including IAC, all ground), and 1 uninsulated wire that was coming off the knock sensor wiring. The knock sensor wiring was encased in a separate gold-looking insulation that I did not unwrap. I did put the uninsulated ground from it in one of the splices I created. Below photo shows the factory splice I cut out. 

I created new wires with 3/8” ring terminals and put them all on the dipstick tube stud. I gave each of the 2 ECU grounds their own respective wire and terminal. And I took a bundle of 3 injector plugs each and made a splice into one wire for both of those bundles. I included the knock sensor ground in one of the injector bundles. 

 

 

I forgot to get a picture of the dipstick tube stud. It’s crowded but it all fit. 

There was also this factory splice that takes the TPS, MAP, CTS, and IAT all into one. I took the tape off and the solder actually looked fine. So I just put some heat shrink around it and taped it up a little better. I forgot to take an after picture but this is what the factory tape looked like. 

 

 

Like I said, I’ve only tested it a couple times over the last few hours, but it seems to be doing better. And I still have the cheap Amazon “A-premium” IAC valve on there. So if you haven’t done so already, it can’t hurt to clean up the wiring a bit! 

Looks great and good luck on the fix working! I hate an intermittent problem because you never know 100% if it's fixed, just that it hasn't happened again lol. I need to do cruiser's tip 6 just to get that out of the way like you did. I've tested the sensor grounds for resistance and never got any but who knows what lies beneath that split loom.

[Rex89]

Yeah I wasn’t getting any resistance either. I’m no expert on electricity by any means, but I think the way the IAC valve stepper motor works is that it requires more amps to work than passive sensors like the TPS or MAP. So even though the grounds had no resistance, those same splices couldn’t handle the higher current draw when the IAC tried to actually move. Maybe there was small resistance in those corroded splices that was enough to starve the IAC of current when under load, especially when cold.

Anyway that’s my amateur understanding of it. Since the IAC grounds through the ECU internally, fixing those sensor ground splices in theory gave the ECU a clean ground path, which let the IAC finally work properly. Time will tell if it’s truly fixed… I’m still nervous haha. 

[hgeranium]

19 minutes ago, Rex89 said:

Yeah I wasn’t getting any resistance either. I’m no expert on electricity by any means, but I think the way the IAC valve stepper motor works is that it requires more amps to work than passive sensors like the TPS or MAP. So even though the grounds had no resistance, those same splices couldn’t handle the higher current draw when the IAC tried to actually move. Maybe there was small resistance in those corroded splices that was enough to starve the IAC of current when under load, especially when cold.

Anyway that’s my amateur understanding of it. Since the IAC grounds through the ECU internally, fixing those sensor ground splices in theory gave the ECU a clean ground path, which let the IAC finally work properly. Time will tell if it’s truly fixed… I’m still nervous haha. 

Good points. I'm going to install that IAC today but if things are still looking fishy then I'll follow in your footsteps and get those splices fixed up. No time like the present to learn how to solder

[Rex89]

I often just use the Watertight Heat-Shrink Butt Connectors from Harbor freight! Just have to crimp them.