TOPIC:

Well I've been all through the fuel injection on my 85 1300 and it's sill fouling plugs. I started with a new set this morning and had them totally sooted in ten minutes. The last thing I can get into are the injectors themselves.
Has anyone had any experience here?
TIA
KZCSI

I'd say the chances of all six injectors being bad are slim to none. Have you checked your fuel pressure and adjusted the TPS? A bad temp sensor would make the computer thinks it's cold and cause it to run rich.
How about an update on everything you have done so far?

Hey Steell,
When I first got the bike the tank wasn't too bad as far as rust goes but it did have a load of very stale gas. After a good cleaning and refurbishing of the electrical system I managed to get it to start up. Right off the bat I got an error code for a faulty throttle position sensor. I found that they are still available from Bike Bandit and or Ma Kaw for $434.00. At that price I wasn't going there till I knew I could afford the rest of what might still be needed. I pulled the TPS off and found that the resistance was off the scale. I managed to get it cleaned up by just washing it in denatured alcohol. The readings came right to where the manual said they needed to be. I have a spare fuel injection computer and I get the same readings with it. Once I got rid of the error code for the TPS the system did not have any other errors. But still it was running way too rich. I can foul all six plugs sooty black in five or ten minutes of running. I've checked the air temp sensor and the engine temp sensor, both read fine. I even checked to see that their readings change with temperature. When I was working on the gas tank I noticed what I thought was the pressure regulator was very stiff so I cleaned it up with some carb cleaner. It seemed to free up just fine. I soon learned that the thing in the bottom of the tank is just a check valve, the pressure regulator looks like a fuel filter and is mounted below the injectors. A few weeks later I checked the check valve again and found that it was totally siezed up. For a while I thought I had found my problem. I capped off the check valve and ran a bypass hose from the pressure regulator right back into the tank through the fill opening. The bike did at least now run but the plug fouling was still occuring. I checked the fuel pressure, it's right at 36PSI. I noticed that the 36 PSI bleeds off to about 20 PSI in twelve hours. Could the injectors be leaking? if so their not leaking badly enough to flood the air box or the crank case.

My theory is that the bad fuel has gummed up the injectors and they are not capable of closing crisply enough to regulate the charge. Any chance of this?
Any input will be appreciated.
Bill
KZCSI

Hey Steell,
When I first got the bike the tank wasn't too bad as far as rust goes but it did have a load of very stale gas. After a good cleaning and refurbishing of the electrical system I managed to get it to start up. Right off the bat I got an error code for a faulty throttle position sensor. I found that they are still available from Bike Bandit and or Ma Kaw for $434.00. At that price I wasn't going there till I knew I could afford the rest of what might still be needed. I pulled the TPS off and found that the resistance was off the scale. I managed to get it cleaned up by just washing it in denatured alcohol. The readings came right to where the manual said they needed to be. I have a spare fuel injection computer and I get the same readings with it. Once I got rid of the error code for the TPS the system did not have any other errors. But still it was running way too rich. I can foul all six plugs sooty black in five or ten minutes of running. I've checked the air temp sensor and the engine temp sensor, both read fine. I even checked to see that their readings change with temperature. When I was working on the gas tank I noticed what I thought was the pressure regulator was very stiff so I cleaned it up with some carb cleaner. It seemed to free up just fine. I soon learned that the thing in the bottom of the tank is just a check valve, the pressure regulator looks like a fuel filter and is mounted below the injectors. A few weeks later I checked the check valve again and found that it was totally siezed up. For a while I thought I had found my problem. I capped off the check valve and ran a bypass hose from the pressure regulator right back into the tank through the fill opening. The bike did at least now run but the plug fouling was still occuring. I checked the fuel pressure, it's right at 36PSI. I noticed that the 36 PSI bleeds off to about 20 PSI in twelve hours. Could the injectors be leaking? if so they're not leaking badly enough to flood the air box or the crank case.

My theory is that the bad fuel has gummed up the injectors and they are not capable of closing crisply enough to regulate the charge. Any chance of this?
Any input will be appreciated.
Bill
KZCSI

Post edited by: KZCSI, at: 2005/10/09 19:24

I guess I wasn't. It'll take some time to adjust.
KZCSI

If it takes 12 hours to bleed down to 20 psi, then I'd say the injector leakage is probably well within specs (could be the reg leaking down). I worked on my brothers Trans Am the other day, and the spec for that called for the system to maintain fuel pressure for less than five minutes

There is a possibility that you are chasing a fuel problem that is really an ignition problem. Have you checked and verified that the ignition is in good shape?

I am familiar with fuel injection systems, but I'm not familiar with the 1300. Wish I had one, then I'd soon be an expert

I can only say that when the plugs are clean the bike runs as smooth as a sewing machine and as fast as a rocket.
KZCSI

Are you running the right heat range of spark plug? You might try stepping up one range and see what happens. And it would not hurt to add fuel injector cleaner to your gas. Hows the air filter look?

Post edited by: steell, at: 2005/10/09 22:58

Hey Steell,
I'm running B7ES NKG's, one range hotter than spec. I've had injector cleaner in the fuel for the last two running sessions. I really can't get it out there and blow it out, no tags and no lights. So far I've kept it close to home and fairly low speed, except for the few manditory spurts just to be sure it was there.
KZCSI

You have already checked the Intake Air Temp sensor, Engine Temp sensor, and the Throttle Position sensor, but what about the Manifold Air Pressure sensor? The MAP sensor measures the vacume in the inlet tract between the butterfies and the valves, and the computer uses that info to determine engine load and calculate (actually it looks it up in a table) fuel required. There is probably three hoses connected to the intake manifolds and then tied together into one hose that goes to a MAP sensor (might only be one hose from one intake manifod going to it). I am assuming the bike uses a speed density system (which it probably does) and not an alpha N system (which it probably don't).
The manual should tell you how to check it, basically you just measure the resistance change from no vacume to vacume.

Oh yeah, you don't have to run the bike hard for the fuel injector cleaner to work, even just letting it idle will work just fine

Post edited by: steell, at: 2005/10/10 07:28

Hey Steell,
I've seen the device you are speaking about and had decided that because there were not codes for it, it couldn't be a problem. I'll pull it off and use a small vacuum pump to see if the resistance changes with pressure.
Thanks
KZCSI

Post edited by: kzcsi, at: 2005/10/10 09:50

It could be bad without throwing a code, it could be telling the computer that there is little or no vacume, making the computer provide extra fuel and causing the motor to run rich.

I assume you have already cleaned all the electrical connections?