P700 700-4 IACV

[Sierra AT4]

I have a 2017 700-4. It would not start and by this I mean it would turn over but not fire up. I troubleshooted it down to the IACV and replaced it. It now starts but takes 5-10 seconds to fire up from cold start. After warming up starts as soon as you turn the key like supposed to. The service manual says the IACV is controlled by a stepping motor. It does not say where this is located. The wiring diagram shows the four wires from IACV go straight to the PCM. I wanted to see if anyone has experience with replacing the IACV and maybe mine needs adjusting somehow.

 

[Admin]

 

[Hello_Darkness]

I have a 2017 700-4. It would not start and by this I mean it would turn over but not fire up. I troubleshooted it down to the IACV and replaced it. It now starts but takes 5-10 seconds to fire up from cold start. After warming up starts as soon as you turn the key like supposed to. The service manual says the IACV is controlled by a stepping motor. It does not say where this is located. The wiring diagram shows the four wires from IACV go straight to the PCM. I wanted to see if anyone has experience with replacing the IACV and maybe mine needs adjusting somehow.

The IACV is not adjustable, the stepper motor is the IACV.

The ecm determines how many steps it needs to extend or retract the barrel of the IACV to maintain idle speed.

The 700 series engine is notoriously hard to start cold, for whatever reasons. Honda uses the MAP sensor pulse to determine when to fire the injector since there is no camshaft position sensor. That's what I attribute the long cranking of certain machines to.

 

[Sierra AT4]

Yes I thought the stepping motor was in the IACV just wanted to see what other people say. You would think being fuel injected would fire right up. on cold start. My boat engine does after sitting for months. I appreciate your help and you relying so timely

 

[Hello_Darkness]

Yes I thought the stepping motor was in the IACV just wanted to see what other people say. You would think being fuel injected would fire right up. on cold start. My boat engine does after sitting for months. I appreciate your help and you relying so timely

The long cranking has no rime or reason, some machines fire right up, some don't. If the the unit is ran on short trips over and over again, it seems to make the cranking worse.

We've had atvs we we're pulling in and out slowly take longer to start, but if you ran them longer and cleaned it out they seemed to be quicker to start.

The 700 is just always a hard machine to start when cold, could be also attributed to the way the transmission is set up with cold oil.

 

[Glock21user]

One of the weird quirks of the 700.
Our 2019 P700-4 always had that issue until I put a big truck battery under the drivers seat and solved most of it.
Still longer cranks than I like but much better.

 

[Sierra AT4]

Is the 1000 this hard to start cold as well?

 

[DG Rider]

Yeah...the old 700 has never started as quickly as any of my carbureted quads did.