TOPIC:

No offense to you technically savvy types, but I like my carbs. I just understand them enough to get them to run decently. If I had fuel injection problems I'd have to have somebody else look at it. Or take some college classes in fuel injection. I understand how injection works, my problem is troubleshooting it. Just not familiar enough with it.

Good luck to you!

Hey Bud,
Actually fuel injection at least speaks to you. Carbs just sit there and taunt you. What I mean is that the computers at least have some sort of internal diagonistic mechanism.
I realize that I'm sounding like someone who has conquered even his first system, which I'm not. But I'm learning fast and I'll be there soon.
KZCSI

I hear you. And yes I must concede your point. Heck I'll even admit I must be getting old and set in my ways. Just when I get somewhat used to something they come up with something new. I guess sometimes I'm stubborn and just refuse to have anything to do with the new stuff because it is new stuff!

Plus I don't have the equipment to read the codes on the vehicles I own that have FI. Haven't wanted to spend the money. But I'm going to have to break down and buy some equipment while I can plan the purchase before it's a case of no choice and have to buy it now!

still like my carbs tho!

Hey Bud,

Actually Ma Kaw missed an opportunity with the old DFI systems. They don't even require the user to purchase a special tool to read the codes. They actually have a led that flashes out a type of morse (sp?) code that you can compare to the manual to decide what the computer is trying to tell you.
KZCSI

Ok, but did you check the MAP sensor? An unresolved problem drives me crazy

Hey Steell,
I've taken this long just to connect up all the electronic junk I'd previously eighty sixed. My thought was to see if somehow the missing electronics were throwing the DFI computer off. I made a funky bracket and reinstalled all of it without the fairing. Talk about a rat bike.

I took it out this afternoon and ran it. No difference still fouling plugs and backfiring.

I'd looked all through the manuals I have, which don't cover an 85, and could find no mention of a Manifold Air Pressure Sensor.

Just the same, the Manifold Air Pressure Sensor was easy to find. It was connected to the intake just downstream of the center pair of injectors. Once I got it off I could see that it was labled a Boost Sensor. It has three wires connected to it. The resistance between any of the wires varied between 2200 and 4400 ohms. I connected a vacuum hand pump and no matter what I do I cannot get any resistance value to change.

I'd have to say you're a pretty smart fella. Thanks a Bunch!

I bet I can get one of these from any decent auto parts store. I'll be looking tomorrow. I sort of doubt that I'm out of the woods yet but at least I'm on the path.

Thanks Again.

KZCSI

KZCSI - Look outside the box for a second. Plugs foul for a variety of reasons... many are not related to the fuel injection. With the key on, check voltage at the coils (bike not running). If there is less than 12.5 VDC, consider doing the coil power mod. Your symptoms sound typical of something in the power path reducing the amount of power to the coils.

Thanks George,
I'll check the coils out.
I just bought a set of plug caps from Jeff. I looked at the coils and it appears that these are the ones with replaceable wires so I'm planning a new set of caps and wires along with the "Boost Sensor".
I'll keep you posted.
Bill
KZCSI

Post edited by: kzcsi, at: 2005/10/31 09:28

It is sounding to me more like electrical issues (weak spark etc). I know that my stock igniter etc was out of whack but would still run the bike. After direct power of the coils and replacing my ignition with a dyna unit when you pulled the spark plug caps off while running you could get a spark jump 1-1 1/2" from the cap to the block. WAYY more spark than it used to have. Spark plug wires and caps are pretty cheap, and wiring the coils doesn't cost even that much. You may also consider the dyna unit if that doesn't fix the issues.

Bill - The power that runs to your coils doesn't go through your plug wires or caps hehe

The power goes through your OLD ignition switch and OLD kill switch and several OLD connectors. Check that power! No point beating your head on the wall thinking you have some strange fuel problem when the problem is a marginal spark caused by lack of powering voltage to the coils.

George,
I was just saying that I'd already planned to work on the secondary side of the coils so checking the primary will be easy while I'm there. I'm going to do it even though I'm willing to bet I have no problem there. If I had a problem with weak spark the bike wouldn't be as quick and eager to start as it is.

But now I do have a real problem and KZR can become the solution. I know that the vacuum sensor is bad. Ma Kaw is willing to sell one to me for $648.00. The part number is 21176-1006. It's called a Vacuum Sensor. I can tell that it's a Mitsubusi brand part. It's probably used in any number of cars. Here's a picture of it.

If any of you folks have access to a parts catalog that depicts this tiny bit of extortion I'd like to hear about it. It's about 2 1/4" long 1 1/2" wide and 3/4" tall not counting the vacuum or electrical connections. It's marked with a Mitsubusi insignia and clearly says Boost Sensor on the front edge it has some letters and numbers painted on that say "J9TO1971" then on the next line it has "4507".

If any of you folks can help me find a reasonable replacement part I might not have to part out this nice 1300.
TIA
KZCSI

Post edited by: kzcsi, at: 2005/10/31 17:39

Hey Folks,
It turns out that what I thought I knew, I didn't.

I've learned that some MAP sensors include an amplifier and they don't just simply vary resistance with changes in pressure. Perhaps some do, but the one used by MaKaw doesn't. I haven't yet figured out any way to confirm whether my MAP sensor works or not. I did learn that it's part of the ignition not the fuel injection. It's function is to dial up the spark intensity at higher throttle, lower vacuum, conditions.

MaKaw's manual list's it as step eight in troubleshooting ignition problems. It's pretty simple, replace it. I suppose that if you've done every thing else correctly the $648.00 will be well spent because without a doubt your ignition problem is resolved.

Oh Well, I put the damn thing back on because I can't see that it's part of my problem. Interestingly, the bike runs with or without it.

Glad I didn't spring for one.
KZCSI