TCI Bad on '03?

[dannymax]

Probly, the reason for cycleing the fuel pump, put pressure on it....a leak is very unlikely tho.

 

[johnpclynch]

I had a tiny crack in my fuel filter, no leak ! Gravity was pulling the fuel towards the tank and the pump was pulling towards the carbs

Disconnect the fuel pump from the carbs and connect a meter or two of hose with a temporary fuel tank on the end (a fuel resistant bottle or similar) hold/tie this above the bike and see if the carbs work normally
PS: disconnect the fuel pump before turning on the ignition or it'll spray everywhere !!!

 

[dannymax]

I had a tiny crack in my fuel filter, no leak ! Gravity was pulling the fuel towards the tank and the pump was pulling towards the carbs

Disconnect the fuel pump from the carbs and connect a meter or two of hose with a temporary fuel tank on the end (a fuel resistant bottle or similar) hold/tie this above the bike and see if the carbs work normally
PS: disconnect the fuel pump before turning on the ignition or it'll spray everywhere !!!

That's interesting! I was thinking a line leak but the nipples on the filter could easily be a leak source.....and it's all vacuum on that side of the pump, a leak is not going to show.

 

[infinity999]

Well this morning I disconnected the fuel pump. Ran the engine until it was out of gas. Drained the remainder of fuel out of carbs 1 & 2. Squirted some fuel into the tops of carbs 3 & 4. Started engine with the choke then pulled the choke off and it actually idled for a few seconds before it ran out of fuel. So after that test I confirmed that the engine will idle with the choke off on cylinders 3 & 4. Why won't cylinders 3 & 4 run the pump connected? Seems that those cylinders are just being flooded with fuel for some reason. Not sure that an air leak in the lines would cause this since it runs fine on cylinders 1 & 2.

 

[Fire-medic]

I didn't check the prior posts, but if you think it's flooding for fuel on the rear cyl's I would be checking the needle valve seats, the needle valves, and the wet-float fuel level in the carbs. Also, maybe switching carbs w/someone-else to see if the bike runs correctly.

 

[m-cman]

I had a float stick one time on a Suzuki Bandit and it filled the crankcase with gas. Had to drain and flush with fresh oil before refilling. Can also fill the cylinder and cause it to lock up if really bad. Good way to destroy an engine or at least the valve train.

I agree with Fire-Medics post on floats, needle valves and/or needle valve seats being a probable cause.

 

[infinity999]

Yep, the only things that weren't replaced with the rebuild were the needle seats. Maybe the O-rings are shot and are letting excess fuel into the bowl and causing them to flood.. I have the new seats but they look like a pain to replace and I'm not sure I'm actually capable of doing it..

 

[infinity999]

Well I performed the final test, it is definitely a carb issue. With the coils from cylinders 1 & 2 disconnected I manually pumped some fuel with a squirt bottle in carbs 3 & 4. Took a bit to get it started with the choke on. After running for 10 seconds or so I turned off the choke and the engine continued to run. I then squirted some more fuel into carbs 3 & 4 and I had it running for a couple of minutes. The idle was below 1k because it was cold and the airbox was off. I just wanted to make sure it would idle and it definitely will on those two cylinders. So, what is the issue here? Float level, needle valves, the seats? The needle valves were replaced but the seats never were. I rebuilt the carbs and Dannymax set the floats. I appreciate al the input every has given on this issue, I feel it's close to being resolved! Yes Danny, I should have taken you up on that offer to test it with your carbs a couple of months ago, oops!

 

[dannymax]

I'm leaning towards the needles and seats being OK Patrick as any problem with them should have showed up during the wet level check. You can polish the seats by chucking a Q tip in a hand drill with a little toothpaste.....shines them right up.

The carb offer is still good.

 

[infinity999]

So are you saying that maybe the needles are getting stuck in the seats and can't move, therefore not closing and causing the flooding?

 

[dannymax]

So are you saying that maybe the needles are getting stuck in the seats and can't move, therefore not closing and causing the flooding?

Stuck needles & floats usually stay stuck and the pump will continue to cycle.

 

[infinity999]

Gotcha, yeah the pump does shut down during the ignition cycle but it does seems that it runs too much sometimes, especially when it run for 3-4 seconds 5 minutes after the bike had been running. The lines all look ok, but who knows there could be a leak there somewhere. Something else I haven't looked into is the possibility of the diaphragms falling off inside the fuel pump. Looks easy enough to take apart. I would think if the carbs were really flooding bad there would have to be something coming out of the vent tubes, but there is nothing.

 

[rabit1]

So.. what happens to this post? Did you get it resolved?

 

[PaulVmax]

Have you checked your earths of the wires and wire continuity