IACV explained

[SportsterDoc]

Re post 10:

I'm familiar with crank position sensor operation. See post one of this thread: http://xlforum.net/vbportal/forums/showt...371&page=2
A failed CPK will not fire. A failing one will cause misfires. It does not match the symptoms.

As for testing sensors, the EOT and TPS have been unplugged and reported in the threads. Posts 35 and 58 in the tps eval for ii issues thread provided values and Dave reported in-spec values in post 59.

All these steps have been documented.

Swapping ECMs is a suggestion in the FSM if there is not 5 vdc sensor power to MAP (5-20), EOT (5-21) and IAT (5-26). Swapping to check for a program glitch is reasonable, if one is available. If nothing else, it is an opportunity to wipe/cycle the ECM connector contacts.

As for erratic output, see posts 1 and 19 of this thread: [url=http://cb1100forum.com/forum/showthread.php?tid=11893]http://cb1100forum.com/forum/showthread.php?tid=11893

In the case of a DTC 1-1 MAP lo, circuit voltage is < 0.2 vdc
This covers "MAP sensor or its circuit malfunction" and fail-safe is "engine operates normally".

In the case of a DTC 1-2 MAP hi, circuit voltage is > 3.9 vdc.
This covers "loose or poor contact of MAP sensor connector" and "MAP sensor or its circuit malfunction" and fail-safe is "engine operates normally".

Just glancing at pages 5-15 and 5-16 shows how well the CB1100 will continue to perform with many sensor codes.

If the EOT is wonky, the only issue is hard starting cold.

If the IAT is wonky, default is 95 F.

If TPS is wonky, default is 0 degrees position

If an O2 sensor is wonky, "engine operates normally"

However, if a fuel injector faults, it is time to push: Engine does not start, injector power, pump and ignition shut down in the event of "loose or poor contact of the fuel injector connector-fuel injector or its circuit malfunction"...fail-safe is not just complete failure...it is out of spec parameters.

I do not have all the answers. At age 71 I am still learning and it took me a while to come up to speed on this issue, at least in trying to understand what worked in the past, what did not work and to figure out why it may not have worked, if it was a reasonable diagnosis. However, the tests done over the last couple months have been thorough, are in harmony with the FSM and compatible with available data on automotive IACV issues.

The absence of codes or the absence of codes being reported added to the challenge.

[Cormanus]

Can someone tell me the part number of this very expensive IACV, please?

If it's just the item Max posted a picture of in #1 of this thread, it's surely not US$1,600. That would buy you pretty much the core of a new throttle body, wouldn't it? Or is the point that you have to replace the entire throttle body?

[max]

Can someone tell me the part number of this very expensive IACV, please?

If it's just the item Max posted a picture of in #1 of this thread, it's surely not US$1,600. That would buy you pretty much the core of a new throttle body, wouldn't it? Or is the point that you have to replace the entire throttle body?

Here you go sir, courtesy of sportsterdoc;
http://www.2wheelpros.com/oem-parts/2014...mbly.html#

It is item # 4 motor assembly. The IACV is 16430-MJF-D01
i also believe there is a later version which is more expensive

According to what i have heard honda only sells the entire throttle body as a spare part hence the hefty price tag.

[Cormanus]

Thanks Max, that's what I thought.

So the critical part is US$96, but you can't have it unless you spend at least US$1,000 on part #3. Or do they insist you buy #2 at US$1,450?

[dave]

Isn't the IACV part number 16430-MFJ-D01? I see that this part lists for $119.13. Does this $1,600.00 include the labor fee?

It looks like I'll be replacing mine, as soon as I can complete the work I'm doing on my VFR800, so I can make room in my garage. This looks like a fairly involved task, and will probably take me an entire Saturday (yes, I'm slow, but I take my time and am very careful, especially when working on something new and for the first time).

I can hear my IACV cycling by listening to the clicking noises it make at start up. Does this mean that it is stuck, and that maybe all it needs is to be cleaned?

[SportsterDoc]

Can someone tell me the part number of this very expensive IACV, please?

If it's just the item Max posted a picture of in #1 of this thread, it's surely not US$1,600. That would buy you pretty much the core of a new throttle body, wouldn't it? Or is the point that you have to replace the entire throttle body?

Here you go sir, courtesy of sportsterdoc;
http://www.2wheelpros.com/oem-parts/2014...mbly.html#

It is item # 4 motor assembly. The IACV is 16430-MJF-D01
i also believe there is a later version which is more expensive

According to what i have heard honda only sells the entire throttle body as a spare part hence the hefty price tag.

Max, I expect you are thinking of the TPS not being listed as separate from the throttle body. The IACV is available, from various sources, such as Honda, BikeBandit, etc.

The "advantage" of purchasing the entire throttle body assembly (2wheel pros shows $1,327.78 list, offered by them for $1,000.48) is that the IACV port would be clean, not warped, with new IACV and new TPS.

Not suggesting this, just clarifying.

Isn't the IACV part number 16430-MFJ-D01? I see that this part lists for $119.13. Does this $1,600.00 include the labor fee?

It looks like I'll be replacing mine, as soon as I can complete the work I'm doing on my VFR800, so I can make room in my garage. This looks like a fairly involved task, and will probably take me an entire Saturday (yes, I'm slow, but I take my time and am very careful, especially when working on something new and for the first time).

I can hear my IACV cycling by listening to the clicking noises it make at start up. Does this mean that it is stuck, and that maybe all it needs is to be cleaned?

Max may answer this better than I, but hearing the IACV cycling indicates that the stepper motor is stepping or trying to step. If crud is preventing full operation, it may not sound much different. The ECM has no feed-back regarding actual movement. For that a servo motor would be appropriate, with an encoder.

Also, it could be moving properly, but an air passage blocked/partially blocked. My only comparison is automotive and comparing ours to a Honda Civic is a different animal.

Again, my suggestion is to first disconnect and then reconnect and see if that makes any difference. Unbolting, lifting the tank and removing the right throttle body cover, disconnecting IACV, feeling for a break in the wires, checking contacts, reconnecting IACV, replacing the cover, lowering and rebolting the tank is only about a 20 minute job. Maybe I took 30 minutes, including taking photos to send to you via email.

Max did a video on using a block of wood to keep the tank up for access to the left side for the TPS, to gain slack in the TPS cable.

Popgun is researching IACV tests on page 5-41 (5-42?) of the manual, which may allow additional electrical testing before removing the IACV. I do not have the manual, so all the FSM info has been courtesy of Popgun.

[pdedse]

Isn't the IACV part number 16430-MFJ-D01? I see that this part lists for $119.13. Does this $1,600.00 include the labor fee?

It looks like I'll be replacing mine, as soon as I can complete the work I'm doing on my VFR800, so I can make room in my garage. This looks like a fairly involved task, and will probably take me an entire Saturday (yes, I'm slow, but I take my time and am very careful, especially when working on something new and for the first time).

I can hear my IACV cycling by listening to the clicking noises it make at start up. Does this mean that it is stuck, and that maybe all it needs is to be cleaned?

A while back, I believe Riko stated his throttle body replacement under warranty would have cost north of $3000, and that John1954 (?) had the IACV replaced at $1500 roughly, again under warranty; most of which was labor if I recall correctly.

[SportsterDoc]

Thanks Max, that's what I thought.

So the critical part is US$96, but you can't have it unless you spend at least US$1,000 on part #3. Or do they insist you buy #2 at US$1,450?

The part strongly suspected of being the main problem is the IACV, which 2wheelpros lists for $95.66. There are several sources, which I would shop for price and delivery costs.

Part 3 is the entire throttle body, which includes that part.

Again, there have been some issues other than the IACV, such as TPS wires and replacing the IACV did not work for a couple forum members...but that may be due to the piston not moving freely and/or air passage obstructions.

Isn't the IACV part number 16430-MFJ-D01? I see that this part lists for $119.13. Does this $1,600.00 include the labor fee?

It looks like I'll be replacing mine, as soon as I can complete the work I'm doing on my VFR800, so I can make room in my garage. This looks like a fairly involved task, and will probably take me an entire Saturday (yes, I'm slow, but I take my time and am very careful, especially when working on something new and for the first time).

I can hear my IACV cycling by listening to the clicking noises it make at start up. Does this mean that it is stuck, and that maybe all it needs is to be cleaned?

A while back, I believe Riko stated his throttle body replacement under warranty would have cost north of $3000, and that John1954 (?) had the IACV replaced at $1500 roughly, again under warranty; most of which was labor if I recall correctly.

Good point. In the custom industrial automation business (assembly robotics, etc.) labor is typically 65% of a project and a Honda dealer typically charges full list for parts.

BTW there is a 50+ post thread on XLForum.net regarding high idle issues.
Sportster went EFI in 2007. This thread started April 2011 and the latest post was this morning. Some Sportster riders, such as Tracy in OZ, reported the issue occurred day 1 on her 2008.

Main "fix" was IACV. Second was TPS. One was reported as EOT.

It is amazing how many EFI bike brands/models have experienced this issue.

[max]

Isn't the IACV part number 16430-MFJ-D01? I see that this part lists for $119.13. Does this $1,600.00 include the labor fee?

It looks like I'll be replacing mine, as soon as I can complete the work I'm doing on my VFR800, so I can make room in my garage. This looks like a fairly involved task, and will probably take me an entire Saturday (yes, I'm slow, but I take my time and am very careful, especially when working on something new and for the first time).

I can hear my IACV cycling by listening to the clicking noises it make at start up. Does this mean that it is stuck, and that maybe all it needs is to be cleaned?

Sorry Dave, i was wrong, i mixed up the iacv with the tps in my mind,thanks sportsterdoc, apologies to all for the confusion, you guys are right, the iacv IS available as a separate spare part from Honda.

There is some good news from johnf415, he replied to a question and said;
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Hi Max,

My bike had the high idle issue, where the engine would idle without any throttle input above 1500 RPM, sometimes surging up to 2000.

However, I did also have the low idle issue at times, although not as frequently, and the behavior was as you described. The engine would drop in revs down to 600-700, and slowly creep back to 1050 if left alone. I recall a couple of stalls, but usually I would avoid that by adding throttle.

I hope this helps, happy to contribute as needed to solve this gremlin!

John

max Wrote:
Hi John, still trying to find the exact fault the slow way, sorry to ask but Dave reports that the bike takes 5 to 10 seconds to go from 700 rpm to 1050 rpm, from memory is that what happened to your bike at any stage or was it just stuck at low rpm all the time?

Just trying to compare the symptoms before i ask him to replace the iacv.

Thanks max
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Sometimes it is the small details that matter, and this makes me feel more confident that the iacv replacement is going to work, by all means clean the iacv contacts first, you may get a pleasant surprise.

[Lord Popgun]

I have sent Sportsterdoc the info he requested and I would suspect he will post on it later. I would, but I’m letting Max and Doc do the posting. They are better at it

Changing or getting to the IACV is a LOT of work. Thus the heavy labor charge. Just accessing the connector is easy as Doc has shown.