Want to buy IAC

[TPEHAK]

Measured coils resistance on the new IAC, it shows 56 Ohm for both coils. So it looks like the old unit coils resistance is probably OK.

Also both new and old IACs moves the same way when I turn engine switch ON.

If I press "Active Intake Test" in the ECM Droid should it move the IAC plunger? I press it and nothing happens with both new and old IACs, they do not move.

It looks like the IAC on the Buell performs self-calibrating each time you turn ON the engine switch. Once you have turned engine switch ON IAC moves plunger down more than moves it up and it does not put big force on the plunger, so plunger touches the hole surface, then yield steps on stepper motor and then moves back to particular distance. So that is why you want to wait until check engine lite came OFF and start engine only after this, because of IAC performs calibrating process, you do not want to start engine instantly before it will have finished this process.

 

[TPEHAK]

Anyone knows IAC (fuel rail) gasket part number?

 

[user_deleted]

Anyone knows IAC (fuel rail) gasket part number?

P0284.5AA
but i'm sure in some way you'll find fault with that info.

 

[TPEHAK]

Thank you.

I ran ECM Droid today with hot engine, and it showed about 10% IAC Position at rear cylinder temperature 200 C at idle 1120 RPM at closed throttle.
When temperature raised to 225 C the IAC Position dropped to 5-6% at idle 1120 RPM at closed throttle. I was not able to achieve check engine light at this conditions but as I understand 6% is very small gap and probably this is close to the IAC limit and close to code 34 when idle RPM will be out of ECM control.

Can anyone confirm normal IAC position at idle speed on healthy motorcycle on hot engine?

The initial IAC position is 40% when I open the throttle.

The guy on the video below says IAC should be about 30% at closet throttle at idle RPM, and 20% IAC means the hole is completely closed for a Ford car. I believe IAC on Buell should show 0% for completely closed hole?

https://youtu.be/ayjhL9jpFH8?t=309

So I see two major issues: throttle body has leakage somewhere, or electric malfunction so real IAC position does not match the IAC position ECM gets.

Throttle leakage can happen due to a few reasons: bad seal between engine and throttle body gaskets, bad seal in fuel rail gasket, bad seal at injectors lower o-rings, bad seal in IAC plunger hole, excessively worn or damaged IAC plunger or damaged IAC hole so IAC can not stop at the hole bottom completely and stops earlier so it causes wrong IAC calibration and bigger gap between hole and IAC tip.

Electric malfunction can happen due to electric noises or damaged wires, so stepper motor yields steps and after some time real IAC plunger position does not match virtual IAC position in ECM. Or there is program malfunction in ECM causing the difference between real IAC position and virtual IAC position.

If this is leakage it is probably very small due to IAC is able to compensate it, but it looks like it is at the very limit of IAC capabilities so sometimes check engine light appears. And it appears only when engine temperature is high.

Another possible source of air leakage is valves seals, probably after I cleaned the valves they started to pass more air from rocker box trough the seals.

 

[TPEHAK]

OK, I found code 34 troubleshooting in 2008 Buell XB Electrical manual. Code 34 means three possible cases

- (P0506 34) Idle Air Control (IAC) system RPM higher than expected;
- (P0507 34) Idle Air Control (IAC) system RPM lower than expected;
- (P0511 34) Idle Air Control (IAC) circuit.

In addition to possible reasons for code 34 I mentioned above there a few more from electric manual: Leaking injectors, excessive oil in crankcase (oil sumping), contaminated fuel, throttle Position (TP) sensor reading of greater than 5% (possible throttle cable misadjustment) or battery voltage reading of less than 9 volts will disable idle speed control.

I believe my case is "(P0506 34) Idle Air Control (IAC) system RPM higher than expected" according the ECM Droid test.

The electric manual says to use DIGITAL TECHNICIAN (Part No. HD-44750) to read the codes, and as I understand DIGITAL TECHNICIAN can say not only the error code, but also the particular case of this code. ECM Droid shows code 34 and says IAC position too low. Does ECM Droid separate the cases of the error code or it shows same message for all cases of the error code?

 

[TPEHAK]

OK, it looks like here is my path according troubleshooting route. So now I have to check manifold intake for leaks with propane

 

[TPEHAK]

I measured the o-ring size for IAC seal: ID is less than 19.39 mm; Section width is about 1.89-1.91 mm. Durometer feels like about 75A. Material is probably Viton. The o-ring I measured is slightly squished so the sizes are not precise. It looks like one of these should fit
https://www.mcmaster.com/#5267T29
https://www.mcmaster.com/#9263K631

So as you can see you can buy dozens o-rings for price of one o-ring packed in Buell bag

https://www.sphdonline.com/products/cf0012-5aa-genuine-buell-iac-o-ring-for-2008-2010-xb-models-u10b

 

[Chicknstripn]

OK, it looks like here is my path according troubleshooting route. So now I have to check manifold intake for leaks with propane

I believe this is EXACTLY what Cole(AZmidget) was alluding to when he asked if you'd read the previous posts in this thread.
This is also what I believe your issue is. Revisit my first response to your post

No sense in resurrecting old threads if you fail to follow the guidance those threads provide.
All this "extra" stuff, pages of nonsense to arrive at a conclusion that was stated years ago, is what discourages the newbies
from researching previous threads for answers.

 

[user_deleted]

on behalf of myself and the vast majority of other board members......is there the slightest chance in hell you'd be so kind as to stop flooding the board with this nonsense? it is now beyond annoying and has entered the realm of unbearable.

 

[BuellyBagger]

wait a minute... its just an intake leak? omg

 

[BuellyBagger]

wait a minute... its just an intake leak? omg

oh yeah, I think I've seen this on a car before. Throws an IAC code for an intake leak because its wildly attempting to find idle, right? there ya go kids, everything you need to know about this thread in 2 posts! Follow the service manual!

 

[AZmidget91]

OMG, the IAC is closed more than it should, maybe to compensate for there being too much air getting paste the throttle in some other way....

 

[TPEHAK]

wait a minute... its just an intake leak? omg

It is unknown yet. I need to perform leakage test first. I do not think this is leak because of I installed fresh intake gaskets, and intake gaskets before this had about 3000 miles when error 34 appeared, and there is no idle issues.

 

[AZmidget91]

Most common reason for a leaking intake seals is installing new intake seals.....

 

[Chicknstripn]

Most common reason for a leaking intake seals is installing new intake seals.....

I have lived this truth.
Installed a new set only to find, upon testing the new seals, that they were leaking. During the second tear down discovered I'd pinched one of the seals between the manifold and head.
I have read stories of this being a very common occurrence.

 

[TPEHAK]

OK. I tried to use propane today to perform leakage test as electrical manual suggested. Do not use propane for leakage test! It looks like this stuff soaks in the motorcycle parts or does something so then motorcycle engine will stall right after start and you will probably not be able to even start it at all!

I attached hose on the propane container and attached aluminum tube on the hose. Then started the engine, wormed it up. Then I tested it and directed it in the air box, and it was probably my mistake, so now propane soaked in the air-cleaner or something. Anyway, after this engine RPM dropped after 5 sec and then raised back . It looks like this stuff can completely stall the engine.

Then I directed the nozzle toward the intake seals and no instant reaction on RPM. RPM started dropping after about 10-15 seconds. For me it looks like propane wend around all this time and then was sucked through the air filter and there is no leakage in the intake gaskets.

Then I decided to perform leakage test according this video



They used brake cleaner, but I decided to use electric cleaner first since it is not so aggressive as brake cleaner so it will not damage the rubber parts. I started motorcycle and it started like ****, it almost stalling. I do not know if this is propane soaked in the intake components and makes it acting so, or propane somehow increased leakage.

Anyway after 5 minuted RPM stabilized and I started spaying electric cleaner on the intake seals and after I sprayed it on the front seal from right side RPM dropped after about 5 seconds after beginning spraying process and IAC raised from 8-10 to 25-30 to stabilize RPM and then after this slowly dropped back to 8-10. So it looks like leakage, right? Then I successfully repeated this test second time with same result. Then I decided to try brake cleaner, sprayed it on the intake seal and got no any reaction, no RPM drop, no IAC position raising, it stayed at 8-10. Then I repeated test with electric cleaner and was not able to affect RPM or IAC position. I do not know what happened, maybe I sealed the leakage spraying this stuff and another leakage somewhere else appeared?

I shut the engine OFF. Then tried to start it again after 10 minutes, and it just stalled right after start. I tried to start engine more than 10 times with no success. Again I do not know what happened. Maybe this is propane, maybe brake cleaner, maybe electric cleaner. I waited about half an hour, connected the motorcycle to a car battery because of the motorcycle battery after so many unsuccessful starts was not able to crank the engine, started the engine, it started rough but did not stall and after a couple minutes stabilized RPM.

So it is probably leakage, but I am not still completely sure because of this propane affected the test somehow, I need to test it again just with brake cleaner spray probably after all this crap will be completely evaporated from the motorcycle parts.

 

[Chicknstripn]

Sounds like you have an intake leak and you've fouled out your plugs.

Why deviate from the test procedures and spray propane into your airbox? I don't understand why you would do that. Performing the intake seal test, in anyway other than what is know to be a valid procedure, is going to net different results. This is true for ANY scientific experiment. And using electrical cleaner! I've never even heard of anyone doing that!
Remember, any deviation in your idle speed after spraying carb cleaner or propane AT INTAKE SEALS(base of throttle body where manifold meets the heads) means you have an intake seal leak. EVEN IF THE REACTION HAS A SLIGHT DELAY.

Before attempting another test I would pull the front spark plug, since it's the easiest to remove, to check if your plugs are fouled.

 

[TPEHAK]

Curiosity.

 

[Chicknstripn]

Curiosity.

You know what that did to the cat!
In this case it's your poor bike that will die!

 

[njloco]

Are going to post up the results, good or bad ?