Gen2 copart special: redemption

Okay guys here's what I've done
- Pulled airbox and visually inspected all the vacuum lines, matched it up against the E33 vacuum hose diagram
- Plugged the vacuum lines to throttle bodies
- Inspected IAPS, APS
- Unplugged the ICSV
- Sprayed everything with WD40 while running and looking for surges
- Checked the voltage from ECM to the IAPS

None of those did ANYTHING.

To be honest, the vacuum hoses and everything look new. Because the basically are, 700 miles on motor.

THEN..I unplugged the IAPS. Idles PERFECTLY.

What does that mean? My brain interprets it as "bad IAPS, just replace." Am I wrong?

Also, this thing took a shot to the exhaust, could an exhaust link or bad o2 sensor lead to a lean condition?
 
Just tested the IAPS

While plugged in to vacuum line and bike is running it shows 2.3v - manual says 2.7v

When vacuum line is open to atmosphere it shows 3.5v - which is correct for today's atmospheric pressure according to lookup chart in manual


this leads me to think
- pressure in throttle body system is in fact lower than it should be (2.3 v < 2.7v)
- pressure sensor is fine
- when unplugged the ECM is defaulting to some stored map


thoughts?
 
Sprayed everywhere with carb cleaner can't get any surging and I sea foamed tank, kind of a shot in the dark.

smoked tested it with a vape pen, nothing I could spot.

Im out of ideas, may have to wait and take it to local shop.
 
amirpc said:
Thanks for the info!

I checked the throttle cables and no binding
I backed out the idle adjustment screw all the way

View attachment 1634883

literally plugged the vacuum line going to evap cylinder

View attachment 1634884

Here's what it's doing, it's like it is adjusting the idle up. After I rev it, it dips down then adjusts back up too.


I had ONE start where it idled at 1300 RPM. I was plugging the hole in back of the evap cylinder with my finger at the time, I couldn't reproduce it. That is when I plugged up the evap tube, never got a normal idle again.

I have ruled out:
  • Binding throttle cables
  • Idle adjustment (backed it all the way out)
  • Vacuum leak from the evap cylinder
The fact that it seems like the ECU is adjusting up the idle makes me think its vacuum.

Questions:
  • The gas in the tank is old, it is the original gas I got with the bike - and it has been sitting since October. Could that cause something like this?
  • Where all should I be looking for vacuum leaks? I looked over the lines from the throttle bodies to the evap cylinder purge valve, seems fine. I took the evap cylinder out of the equation. Where else?
Click to expand...
Did you loosen the throttle cables up also? Did you test the AIC?

I’m sure in flash they disabled pair valve system did you block yours off? Did they disable secondary plates that is common also.
 
Last edited:
Mathewrussell52 said:
Did you loosen the throttle cables up also? Did you test the AIC?

I’m sure in flash they disabled pair valve system did you block yours off? Did they disable secondary plates that is common also.
Click to expand...

Thanks for suggestions!

Just spoke to the previous ECM owner. He said that he had removed PAIR valve and the ECM was flashed.

I have PAIR valve installed still. Is it possible that this is causing it?

Also, throttle cables are loose. What is the AIC?
 
Mathewrussell52 said:
Did you loosen the throttle cables up also? Did you test the AIC?

I’m sure in flash they disabled pair valve system did you block yours off? Did they disable secondary plates that is common also.
Click to expand...

when you say disable secondary plates, is that removing the secondary throttle butterflies? Or something else?
 
amirpc said:
Thanks for suggestions!

Just spoke to the previous ECM owner. He said that he had removed PAIR valve and the ECM was flashed.

I have PAIR valve installed still. Is it possible that this is causing it?

Also, throttle cables are loose. What is the AIC?
Click to expand...
amirpc said:
Thanks for suggestions!

Just spoke to the previous ECM owner. He said that he had removed PAIR valve and the ECM was flashed.

I have PAIR valve installed still. Is it possible that this is causing it?

Also, throttle cables are loose. What is the AIC?
Click to expand...

ISC . Idle speed control.
 
Mathewrussell52 said:
You can set them to open when. I disabled and removed mine.
Click to expand...

Okay so ECM guy says he removed his butterflies AFTER the flash. The flash may have disabled them though. Is there a way to check you think?

Mathewrussell52 said:
ISC . Idle speed control.
Click to expand...

I haven't tested it, but when looking through the manual there were a couple items that mentioned it under "poor idle"

1619464877279.png


It seems like in the book it shows there is a software "target" idle RPM:
1619465118412.png


It seems like there should be a code thrown if the idle is too high relative to desired idle (C40). So the fact that that code isn't being thrown makes me think something is disabled in the ECM with the flash?

Also, I will test the ISC as the book outlines tonight.
 
amirpc said:
so it runs and idles the exact same if I just unplug ISCV. What does that mean?
Click to expand...
Could be wrong but should it should just pull air from around the throttle bodies. If you plug it does it die? That might be a better test if not you have to have a vac leak.

I thought I read the butterflies cycle when turned on. But it’s been a long time since I messed with them but when you turn it on it looks like they should be 100% open.
 
I do believe there is less than expected vacuum because the IAB voltage reads 2.33v rather than the expected 2.7v in the book, and I actually did put a vacuum gauge in there and confirm that the pressure it reads maps to ~2.4v on the IAB.

I've basically done everything humanly possible as far as I can tell to figure out the vacuum leak:

- Pulled throttle body assembly and inspected then zip tied EVERY SINGLE vacuum line, including the big ones up by the airbox
- Blocked off the PAIR valve ports
- Swapped the IAB sensor with rear, plus done the above vacuum reading with gauge
- Tried with/without ISCV plugged in
- Backed out the idle speed bolt
- Checked the throttle lines for kinking, but the assembly is clearly bottoming out not due to tension on lines
- Seafoamed gas and cleaned the injectors
- Left secondary butterflies in but confirmed with previous ECM owner that he had his in when he got flashed too

IMG_0899.jpeg

IMG_0925.jpeg

IMG_0930.jpeg

IMG_0912.jpeg

IMG_0960.jpeg


It still idles at like, 1800 once it's warm.

I'm going to just stop chasing this for now and get the bike together, get a few miles on it, get clean gas in it, etc. See how it goes.

Anyhow, got the new shifter and linkage in, works great.

AND good news! the shop checked the wheel and axle and they are straight - its just warped rotors.

I don't know much about brake rotors. The shop is saying OE parts are really backordered right now and they aren't able to find any (used or otherwise).

So questions:
- Is it possible that a throttle body synch will fix this?
- Any ideas on what to do re: brake rotors? Will another brand in the same size work? Any suggestions?
 
amirpc said:
I do believe there is less than expected vacuum because the IAB voltage reads 2.33v rather than the expected 2.7v in the book, and I actually did put a vacuum gauge in there and confirm that the pressure it reads maps to ~2.4v on the IAB.

I've basically done everything humanly possible as far as I can tell to figure out the vacuum leak:

- Pulled throttle body assembly and inspected then zip tied EVERY SINGLE vacuum line, including the big ones up by the airbox
- Blocked off the PAIR valve ports
- Swapped the IAB sensor with rear, plus done the above vacuum reading with gauge
- Tried with/without ISCV plugged in
- Backed out the idle speed bolt
- Checked the throttle lines for kinking, but the assembly is clearly bottoming out not due to tension on lines
- Seafoamed gas and cleaned the injectors
- Left secondary butterflies in but confirmed with previous ECM owner that he had his in when he got flashed too

View attachment 1635071
View attachment 1635072
View attachment 1635073
View attachment 1635074
View attachment 1635075

It still idles at like, 1800 once it's warm.

I'm going to just stop chasing this for now and get the bike together, get a few miles on it, get clean gas in it, etc. See how it goes.

Anyhow, got the new shifter and linkage in, works great.

AND good news! the shop checked the wheel and axle and they are straight - its just warped rotors.

I don't know much about brake rotors. The shop is saying OE parts are really backordered right now and they aren't able to find any (used or otherwise).

So questions:
- Is it possible that a throttle body synch will fix this?
- Any ideas on what to do re: brake rotors? Will another brand in the same size work? Any suggestions?
Click to expand...
Not sure about the idle...it's a real stumper but probably something real simple...

As for rotors, lots of people here use Arashi rotors and like them.

I have EBC 5.5mm rotors on mine and they work great but they aren't cheap.
 
Stock 2020 ECM idles fine, flashed 2015 ECM rough / high idle.

It's not just a high idle it fluctuates in a 400 rpm band, the ECM is clearly compensating for something.

The rock solid idle on 2020 ECM makes me believe it's got no vacuum leak.

Idone everything I can to make the bike match the state of the flashed ECM:
- Removed PAIR and sealed
- Deleted charcoal canister and blocked vacuum lines

At this point the only things I know for sure are diff from the 2015 ECM and stock:
- 15 had a power commander and a tune
- it had deleted secondary butterflies
- 15 ECM was not a CA emissions bike (2020 one was)

Thinking I'm going to ride it 50 miles or so and see if it's maybe a learned value. After that...

There is a local dyno tuner AF1 I am thinking once I've got bike back together I'll have them do a tune. Thoughts?
 
amirpc said:
Stock 2020 ECM idles fine, flashed 2015 ECM rough / high idle.

It's not just a high idle it fluctuates in a 400 rpm band, the ECM is clearly compensating for something.

The rock solid idle on 2020 ECM makes me believe it's got no vacuum leak.

Idone everything I can to make the bike match the state of the flashed ECM:
- Removed PAIR and sealed
- Deleted charcoal canister and blocked vacuum lines

At this point the only things I know for sure are diff from the 2015 ECM and stock:
- 15 had a power commander and a tune
- it had deleted secondary butterflies
- 15 ECM was not a CA emissions bike (2020 one was)

Thinking I'm going to ride it 50 miles or so and see if it's maybe a learned value. After that...

There is a local dyno tuner AF1 I am thinking once I've got bike back together I'll have them do a tune. Thoughts?
Click to expand...
It looks as though you've found your problem, the ECU was bad....glad you found the issue
 
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