Start Valve Sync - before and after

Yesterday I did my first Starter Valve Sync. The pictures show before and after "measurements" on the CarbTune II pro. I bought two rubber stoppers from Lowes for the reed valve plugs (at the valve covers) and used four brass 1/8" male-to-male hose barbs to join the ST's vacuum hoses to the CarbTune's hoses with the in-line restrictors (included w/ the CarbTune). After finishing the Sync, I put all the fittings back, and reset the ECM code. Seems to runs smoother now (that's what I'm supposed to say here, right?). :


Matt

How's the ECM code re-set?

In a thread titled "Bad MAP sensor?", there a post from wjbertrand that describes the reset procedure:

"... With the engine off, kill switch on and the side stand down, you short (I use a bent paper clip) two terminals (pink/green to brown I think) in the red diagnostic plug under the right side of the passenger seat. With the jumper in place, turn on the key. If there is an error code there, the FI light will blink. Have a look at the service manual to interpret the blinks. While the FI light is blinking, pull the jumper out. The FI light will stop blinking and stay on solid. Make sure to stick the jumper back in while the the FI light is still on (there's not much time) and watch to see if the light starts blinking rapidly. If so you have cleared the codes. At this point turn off the key and remove the jumper.

I like to repeat the first part of this to make sure the code has been cleared. If you replace the jumper and turn the key on again, the FI light should glow steadily if there are no codes in the memory. "

The procedure can also be found in the FUEL SYSTEM section of the FSM (on pages 5-8 and 5-9 in my 03-04 manual).

Hope that helps,
Matt

Usually I just leave the MAP plug hooked up to the airbox lid while it hangs over the side. That way you don't have to reset the ECM.

I believe somebody here (too lazy to find out who/where ) said they T'eed the MAP sensor into Starter Valve #1 (the fixed one) during the sync. The MAP sensor saw vacuum, so an error didn't occur. In reply, I think BLRFL said he thought the MAP error was desired, because it caused the EFI system to default to preset (i.e. "limp home") parameters across-the-board, which is desired for calibration purposes. Two points of view.

(Sorry if I misunderstood either gentlemen's explanation.)

Matt

Black Magic said:

The MAP sensor isn't hooked up to air box cover; the IAT sensor is.

Even if the IAT sensor is reconnected, the MAP sensor still gonna generate errors during SVS, cuz there is no vacuum from any cylinder feeding it.

The manual ask to blip the throttle to create the map sensor fault. Prolly it want ECM in fault mode during SVS.

Click to expand...

opps, my bad,,,,,whatever its called, I leave it connected during the sync.

st13fundred said:

I believe somebody here (too lazy to find out who/where ) said they T'eed the MAP sensor into Starter Valve #1 (the fixed one) during the sync. The MAP sensor saw vacuum, so an error didn't occur. In reply, I think BLRFL said he thought the MAP error was desired, because it caused the EFI system to default to preset (i.e. "limp home") parameters across-the-board, which is desired for calibration purposes. Two points of view.

(Sorry if I misunderstood either gentlemen's explanation.)

Matt

Click to expand...

I could buy that. When I performed my Starter Valve Sync a few weeks back, I forgot to blip the throttle. The bike ran rough for about 10 seconds and then kicked into some mode where the RPM increased and the idle smoothed out. It seemed clear to me that the ECM sensed a change in the vacuum (MAP fault) and kicked the system into another mode. I think the blip is to speed that process so the bike isn't idling rough for so long. I think that Engineers knew exactly what they were doing when they specified the procedure to lose vacuum while syncing the valves.

I did mine as T,Tom suggested which is how he carries out all of his, - leave the iat sensor connected and tee no 1 Cylinder into the carbtune and map sensor, bike will run as normal with no fault codes at all, worked for me, also left the pair hoses connected to the cam covers

st13fundred said:

...I think BLRFL said he thought the MAP error was desired, because it caused the EFI system to default to preset (i.e. "limp home") parameters across-the-board, which is desired for calibration purposes.

Click to expand...

I did say that, and while I can't say I'm sure that's how it works, it would make a heck of a lot of sense. That's what the service manual instructeth, ergo that is what I doeth.

--Mark

panman40 said:

I did mine as T,Tom suggested which is how he carries out all of his, - leave the iat sensor connected and tee no 1 Cylinder into the carbtune and map sensor, bike will run as normal with no fault codes at all, worked for me, also left the pair hoses connected to the cam covers

Click to expand...

Did the same things too as it simulates actual conditions better IMHO. No fault codes generated and a smoother result afterward.

What does a starter valve sync do in terms of engine performance?

(I never had a EFI motorcycle before)

I did read Wiki on the web regarding EFI, throttle bodies, fuel injectors, sensors - air in exhaust, heat, crank, air intake, etc. Still don't know what those air tubes do.

The starter valves are air bleed valves. When the throttle plates are closed they are the engine air supply. They are mechanical and operate using linkage tied to the idle adjust screw and the SE valve (SE valve will open them based on engine temp. for cold start idle increase)

They are synced so each cylinder provides equal power for a smooth idle and throttle transition. Off idle they carry less weight but still play a role in overall performance.

I recommend following the manual for the starter valve sync. Set the code for the MAP sensor, this (as noted) fixes the MAP sensor value to keep it from compensating for a vacuum change when the starter valves are adjusted. The middle letter in MAP is very important.
It's "absolute", meaning it's very acurate and sensative. It's reading of the manifold vacuum is precise. Absolute is also used in rating filters, in this application it means one pass 100% filtration. They are very expensive. In the hydraulic application the price is in the $80.00 + range. I mention this to stress the importance of the word absolute.
If the manual states to unplug and set the code then it should be done. There is no reason not to.

OK I think I am going to get a scolding here... I did this sync a bit ago. To start with my carbtune looked a lot like the last pic before I started, and I found that no real adjustment was needed (16k miles on an '06). Here is the kicker, I have never cleared the ECM code afterwards. I just figures since the bike was running nice and the FI light wasn't blinking or anything all was well. AM I DELUSIONAL, SHOULD I RESET MY ECM? (sorry for the hijack)

You will have a "ghost" code in your computer. Down the road when you DO have a running problem first thing you do is pull codes and that MAP sensor code will come up. That will send you down the wrong road for troubleshooting.

Always erase codes. If you have an intermittent problem, write the date and code down and erase it again.

On a side note, why don't we just have one throttle plate but multiple injectors like cars do?

another side note, next time I'm going to T the map sensor. I know it's against the manual but changes in MAP readings won't change how much air is going in each cylinder at idle.

Pete in PA said:

You will have a "ghost" code in your computer. Down the road when you DO have a running problem first thing you do is pull codes and that MAP sensor code will come up. That will send you down the wrong road for troubleshooting.

Always erase codes. If you have an intermittent problem, write the date and code down and erase it again.

On a side note, why don't we just have one throttle plate but multiple injectors like cars do?

another side note, next time I'm going to T the map sensor. I know it's against the manual but changes in MAP readings won't change how much air is going in each cylinder at idle.

Click to expand...

Ah but it does, just differently then one would think. As you increase or decrease the amount of air through the starter valves the MAP will see it and add or subtract fuel as required. This in turn will change engine RPM's and manifold vacuum. You will end up fighting the MAP sensor, that's the reason Honda wants it out of the picture.

If it was an ECU controlled idle system using a stepper motor or IAC valve you have to lock the idle control or you would fight it. As you adjust the air bleed or throttle stop the idle control will go in the opposite direction. You can reach a point that bottoms the idle control, it needs to operate in a specific range, and damage it. You don't have this system on your bike but the reason for Locking the MAP is the same.

It is your bike so have it but I would wonder why you would.

Your just balancing the starter valves, if you do this and the engine is a little rough that's OK. Once balanced and the MAP is reconnected and the code cleared everything will fall into place.

I'll give you the best advice that was ever given to me by a Volvo trainer.
"Do what the book says and you'll never be wrong"