Help - throttle body sync is killing me!

[MC MUSTANG]

Hokay - I have to take a break - but. I have been working on my throttle body sync all day.... it should not take this long - I know!
So - wow. Man, is there gonna be a "Don't do it this way post after this!"

So, here's the deal. No one around here has ever heard of a manometer - so I decided to go the backyard way - four separate vaccum gauges. So, I have the airbox off, all the lines appropriatly capped, etc. So, I fire up the scoot and it is very rough! using the idle screw, I try to keep the tach at 1150-1200, but I can't get a stable read on the gauges that way. So, I bump her up to 3k where I can at least read the gauges. +/- 20...
Anyway, I get them to where they are sync'd, put the airbox back on, but I have black smoke and backfiring.... not to mention, I have to keep adjusting down the idle because after making a few adjustments, it starts to climb... well, I walk away, then come back after about 15 mins (cool down for the bike and for me)...
So, I do it again, get them even better sync'd, but now after putting the airbox back on, I am getting whitesmoke and more backfiring. Smell of fuel is heavy... she has never done this before so I know it is my adjustments... but I need some help! I am going to dinner now, before I hurt Bessie out of sheer frustration! Anyway... thanks for listening, just airing my problem is somewhat theraputic...
I really want to get her back on the road! Help! Thanks...

 

[MC MUSTANG]

Hokay - I know she is running rich, here's what would really help. I think I am going to nominalize the adjustment screws and start over... so, if others are doing the throttle sync at 1150 rpms, what psi or centimeters should I be looking for? In jinksters post, I saw his gauge reading 21ish (Trying to remember)... any help. The Zuk book doesn't give a value for max disparity or for nominal pressure....

 

[omslaw]

Shawn - did you hookup the MAP (I think that's the one) sensor? It's the one in the airbox...did you unscrew it from the airbox and hook it back up?

Also, where did you pickup the dial gauges?

 

[Wag]

When you reassemble everthing, make sure you reconnect EVERYTHING. There is a little green sensor that screws into the left side bottom of the airbox that will really mess things up if you don't have it connected. Also, make sure it's connected while you synch the throttle bodies.

--Wag--

 

[GIXERHP]

So did you get it running wright yet?

 

[MC MUSTANG]

No, not yet, PM sent...

 

[atticdog]

did you keep the map sensor connected?
like mentioned above?

 

[MC MUSTANG]

Yep... reconnected everything. I actually think that I have got it.. all the valves are running at 13... the problem though, is that I don't know where this falls on the range of acceptable values. I am going out to put the airbox back on and see how she runs. To everyone who has posted, thank you! Now, if someone has a Haynes manual, in the begining of the Routine maintenance and servicing chapter there are values for the max allowable disparity between the valves.... I need to know what that is as well as if someone could tell me what I should be reading at 1150 for idle...

 

[loboboy]

each bike is different in the amount of vaccum that will read on the gauges. All you want to do is set them all the same, no matter where the needle is on the gauges. If the gauges are hard to read it is because of the erratic vaccum signal, this is normal, my gauges have a way to regulate the vaccum pulses by pinching the rubber line to where it will stabilize the needle. once this is done then I set my idle around 2000-2500 RPM and sync them there, and normally this will give a reading of around 19-21 inches of vaccum. Once you have everything back to gether and it still sounds flat and sluggish at idle then you are way off from where you should be and may need to take it to someone who can help.

If you were closer to me I would do it for free but I don't know where you are located. Also Jinksters write up about this is a great procedure to follow and as along as you don't have any other issues it should work as advertised.



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[MC MUSTANG]

Got her finished... all the valves at 13 and she runs and sounds great!

 

[DAB]

I experimented with vacuum gauges way back when on one of my first bikes and they were almost unusable due to the "pulsing" that makes the needles flicker. I tried using tube clamps to damp them but it still wasn't acceptable.

Next, I used Mercury column manometers and these were much more accurate as the weight of the Mercury damps out the pulses.

For the 'Busa I decided I would invest in the OEM Suzuki gauges (not cheap but well made.) These use balls bearings in tubes with screw adjusters to set them to the same initial value. They are more compact than the Mercury guages, and I don't have to worry about potentially sucking a Very Bad Substance into my engine (Mercury will eat through Aluminium.)

 

[Okibusa]

MC Mustang; I'm not mechanically incline at all. What I would like to know is what is the purpose of using a manometer?

Thanks

 

[cutter]

I did this job yesterday using dial gauges. Each line has a needle valve that you close down just until the pulsing stops. Got them from Dale Walker's Bandit website.

+1: It doesn't matter about the absolute value. Just make them all the same. You want to balance 1/2, then 3/4, then adjust the center screw until 1/2 and 3/4 are the same. Blip the throttle in between adjustments to settle the linkage.

Mine were a bit out of adjustment and now idle is noticeably smoother. Hope to get out today for a highway cruise.



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[MC MUSTANG]

MC Mustang; I'm not mechanically incline at all. What I would like to know is what is the purpose of using a manometer?

Thanks

Oki -
If you still have this question, the manometer is a type of vacuum guage ... you use it to measure and align the vacuum pressure at each of your throttle body ports. It is a four column block that shows each pressure value... that way you can dial in your throttle bodies in this case so that they all read the same.... better fuel economy, better throttle response...
should be done every 7k or so....

 

[Okibusa]

Hmmmm, thanks for the info. I've never heard of this. I've been having my throttle cable adjusted.

Thanks!

 

[busa boyz]

so mustang did you figure out the problem you were having ?
was it the sensor



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[MC MUSTANG]

so mustang did you figure out the problem you were having ?
was it the sensor

Actually, the problem was the cheapo gauges I was trying to use. Got a better quality guage and it worked out right away!

 

[Busa Dreamin]

I did this job yesterday using dial gauges. Each line has a needle valve that you close down just until the pulsing stops. Got them from Dale Walker's Bandit website.

They look nice and the price $64.95 sounds ok.
I guess it's another option over Mercury.



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[HRJR]

I just bought a Motion Pro mercury gauge from my dealer. Yeah, they were not supposed to sell it (CT) but the parts guy didn't know any better (I did tell him about the law), or didn't care.

I'll be playing with it soon.