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Discussion Starter #1
I have not updated my progress on this project in a long time. A computer crash then work schedules have kept me from doing any more work on the bike.
After the tranny and engine overhaul everything worked great. But of course a new issue has came up.
Early this spring it ran good. Things got busy and I have not started the bike for a few months. Yesterday, in the 100 degree heat, I went out to take her for a little ride. It started like always, a little choke and hit the button. Third thump it fired up and ran. I let it sit and run like usual with the choke on half while I put my helmet on, then I dropped the choke. As soon as I shut the choke down it missed and started sputtering, so I gave it a little choke again. It had been idling about 30 seconds by then. The choke usually helps get it evened out until it warms up a bit but this time it died. I could not get it started again. I had good spark, but in the heat I didn't check any more than that, so I decided to leave it until evening.
Last evening when it finally cooled off in the shop I went back out to work on it. It still wouldn't start. I opened the drain screw on the bottom of the float bowls and only a small dribble of gas came out. I pulled the line from the fuel pump and a very small amount of fuel ran out. Maybe a tablespoon. I hit the starter button and it would burp gas every revolution.
I noticed that when I turned the kill switch from stop to run with the key on the pump would click and burp our a little gas.
With the line from the pump to the carbs off I opened the drain screw on the bowl again, allowing air into the line gas ran out of both the hose and the drain. I then pulled the line from the tank to the pump and gas ran out in a good stream.
Put everything back together and tried it and it started right up.
Today in the heat I went back out to go for a ride. I had the same problem as yesterday, it started for a few minutes then ran rough, then killed out. Now it won't start again.
Any ideas?
When it cools off I am going to go through the test proceedure for the pump. Any other ideas?
 

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Sounds like vapor lock -- try taking the cap off the tank and see if that makes a difference. If so, make sure your venting is clear (don't know if yours has a tube or it's in the cap..)
 

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I had pretty much the same issue with my '96 VT1100 a couple years back. The bike would start and run, but die for no reason. It would start up again and go for a short distance and die again. After some investigating, I found it was infact the fuel pump that was bad. It passed the pump test just fine, but just not the volume test. It would pump fuel all day, just not enough!
I replaced it with another used one (off of a low mileage 1100 Saber) and it runs just fine.
So they may work, and pump gas, but just not enough to keep the bike running.
There's also a relay the needs to be checked to see it it's working right. You can bypass it with a jumper wire to see if that's the problem first.
 

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Discussion Starter #4
Thanks or the ideas. Tonight when it cools off in the shop I am going to give it another look.
Yesterday when it was not starting I did open the gas tank, added a galon of gas and it still wouldn't start. But with the heat a vapor lock is a good thought for sure!
 

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Discussion Starter #6
I like the aftermarket pump idea.
Last night I finally found time to check out the bike a little.
Following my free downloaded service manual I tested the relay. I connected a volt meter to the blue/black wire between the pump and the relay. I left it plugged into the pump, stuck the pos probe of my volt meter to the blue/black wire and the neg probe to the neg post on my battery. Turned the key on, kill switch in the run position. The book said there should be no voltage reading. I was getting a 0.17 reading. Bumped the starter button, it should have a voltage reading. When I bumped the starter button I got a voltage reading of around 8 volts. It of course was jumping up then back down to 8.
When I released the starter button it maintained a voltage reading AND the pump was thumping away. As soon as I removed the volt meter lead from the neg. battery connection the pump shut off.
While I had the voltmeter connected between the blue/black wire and the negative battery cable I could hear the pump running and the bike wanted to start. It never fires and tries to start while the engine is cold without choking it.
I have not tested the volume of the pump output yet so the pump could still be bad but for now I am wondering if the relay is bad.
 

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hook everything back up to the way it was when you started----put the fuel out hose to the carbs into a bucket or bottle----pull the 3 wire connector off the fuel pump relay----jumper the blue/black and the black on that connector you just pulled with a paperclip----turn the key on----pump should start pumping right when you turn on the key---if you measure the volume and that is good or close to good---then the pump is good-----hook the relay back up and try it----if it runs like poop or won't start the relay is your problem---------roll with the paperclip and dont worry about it, cause a new relay is like 65 bucks!!!-----if you wreck, just remember to turn off your key before you get loaded up in the ambulance:shock:

dont worry about readings on the voltmeter so much--just do the check above and you will know---i suspect a bad relay
 

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Discussion Starter #8
Thanks for the advice! I will do that later tonight and see how it flows.

If I do bypass the relay with a permanent wire jump (assuming the relay turns out to be the problem) I am assuming there should be no problems damaging the pump? I would assume the relay is just a shutoff to kill the pump when the engine is not turning over to prevent spillage during a wreck, or to prevent spillage in the event o a stuck float? Does the pump shut itself off once pressure is built up in the carbs, or does it bypass fuel and keep ticking away?
I suppose I could wire it to a switch on the bars to turn the pump on and off, but I don't want to feel like I am starting the space shuttle when I fire the bike up! Plus it is just one more thing for me to forget.
I will see what happens tonight.
 

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no it will not harm anything, you are very correct--its just there as a saftey to cut the fuel when the motor stops---the way i understand it is that the honda oem pump will quit pumping when the float bowls fill up and close the float valves in the carb---i guess it senses a back-pressure, it does not bypass the fuel

in my case with the aftermarket mr gasket pump i think it just tries to pump against the closed valve but it cant overcome them because its only a 2 psi pump----if it was a 10 psi or something i would probably have problems

Just jumper it and see if that fixes it and rock on
 

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Discussion Starter #10
Well, the catfish were biting so I didn't work on the bike as long as I thought I would.

I did run a jumper wire between the blue/black and the black wires and the pump ran constant. The bike started and ran. But when I removed the jumper wire it kept running. So, at this time I really don't know a lot more than I did. I couldn't find a container to pump gas into to test the flow. I need one with measurements marked to know the volume.
Maybe tonight.
 

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did you unplug the connector from the relay and jump it or did you jump it while still plugged in from the backside?

when you say it kept running---do you mean the bike or the fuel pump?

i dont see how the pump could run with the relay connector unplugged and jumper removed-----the bike on the other hand may run for a few minutes until all the fuel in the carb bowls is used up.

maybe a previous owner wired the pump directly to an igniton hot wire already or something, trace the wires coming off the pump,----one should go to that relay plug connector.
 

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Discussion Starter #12
After unplugging the jumper wire I put everything back together again. I then started the bike and it ran for about 10 minutes without a problem.

I left the connector plugged into the relay. Was this the right way?

I connected the jumper wire, heard the pump running, hit the starter button and it fired and ran. The jumper wire got a little warm while it was running. After a few minutes I removed the jumper wire and the bike continued to run. I shut it off, started it again and it ran fine.
I think next I will follow your advice and pull the seat so I can trace the wires and make sure they are all good.
The problem to begin with was intermittent though, sometimes it would run other times (especially when the weather was very hot) it wouldn't start.
 

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thats why it kept running-----pull the plug off the relay, let it hang loose, nothing plugged into relay---we are taking the relay out of the system all-together

with the plug loose---- jumper the blue/black and the black, so that your fuel pump will run when the key is on

leave it like this for a few weeks or days and see if the problem happens again---if it doesnt then the relay has been your problem the whole time

if the problem returns with the relay out of the system,,,, then its the pump or maybe the coil or ignition system

we are just trying to determine if its the relay or not---unplug the connector from the relay and jumper it on the connection side not the back side

you wont hurt a thing with that relay unplugged and the wire jumpered--ride it for while like that and see if the problem happens again

Good luck--keep me updated, intermittant problems can be hard to figure out, dont get discouraged if it happens again, we can narrow it down, eventually
 

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Discussion Starter #14
I am almost convinced something in the pump is bad.
Last night I disconnected the relay like you said to jump the wires. When I did this I noticed the relay had a crack where the wires connect.
My problem seemed to be worse when it was hot outside, about 100 degrees with 90 percent humidity. By evening when it was cool it would start and run. So I thought maybe the relay was drawing moisture.
I jumped the wires on the relay, turned the key on and the pump started running. I went through the volume test on the pump from my book, jump the wires and run the pump for 5 seconds. The book says measure what it pumps then multiply by 12, the minimum for a good pump is 22 ounces. I got just under 5 ounces pumped in 5 seconds, which equaled a little over 50 ounces per minute. Not sure if that was correct so I ran the test again. In 5 seconds I pumped just over 4 ounces.
I re-connected the fuel line and turned the key on. The pump ran (because it was still jumped) for several seconds. I shut it then turned it on again. The pump ran for a few seconds then stopped. Then it started pulsing, running a second or less then stopping, then running again.
I then removed the fuel line and the pump ran continuous pumping gas into my gas can. I stuck my finger over the end of the fuel line (outgoing line from the pump) and the pump shut off. I released my finger and the pump ran again.
I then re-connected my fuel lines and turned the key on again, the pump ran a few seconds and stopped. I cranked on the bike but it wouldn't start again. I am wondering if the pump is getting hot and losing connection internally or something.
I did verify again, when it does not start I am getting spark to both cylinders so the problem is fuel related.
I am leaning towards the pump being bad, it is my understanding the pump on the 85 shadow 1100 should run continuous when the relay wires are jumped.
Oh, one other thing, while the pump was jumped, key was on, and the pump had stopped, to verify it did not have a pressure switch to shut the pump off I opened the drain screws on the bottom of each float bowl. A little gas dribbled out, which should have relieved pressure and kicked the pump back on if it was a pressure shutoff. A little gas drained out of the float bowls but the pump did not kick back on. I shut the key off for a few minutes then turned it back on. When I did the pump ran again for a few seconds then stopped.
 

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hmmmm-----it does sound like the pump is probably bad----when i tested mine i ran the outlet to a gas can---hit the key and it pumped good for 5 or 10 seconds then just quit----turned key off, then on and nothing happened for bout 30 seconds then it just sprang to life and started pumping-----few more flips of the key and it was definately an intermittent pump

im 99% sure back pressure cuts it off

i suggest jumpering the relay wires-----running the outlet to a gas can, so there is no back pressure and flipping the key on and just waiting a few minutes

if it cuts off at all,,, ----you got a bad pump

if it pumps good for a minute--try flipping the key off then back on, if you flip the key on and it doesnt come on or takes like 20 seconds to come on---you got a bad pump

basically it should run and quit running with the key everytime

I bet you got a bad pump----check out that thread i sent you about installing a mr gasket 2-3 psi pump from autozone if you wanna save 50 bucks cause i think the oem is like 100 bucks

good luck---you've done some good troubleshooting, and yes when you drained some fuel out of the bowls, it seems like the pump should have come on----mine was easy to tell because it was randomly running and then quiting right before my eyes, your's seems a little more fickle to heat or something

Another thing you may wanna do is just connect the outlet of the tank right to the inltet of the carbs to make it a gravity fed and take the pump out altogether. then hook the pump to a power supply or car battery and just run it for a while to see if it cuts off on its on, to further troubleshoot.

some research told me that as long as you have a pretty full tank, it should gravity feed just fine----the bottom 1/3 of the tank though is lower than the carbs and it wont gravity feed good if you get near reserve or on reserve----i think there is a guy on here that runs his that way with no problems, i think he responds to me in that thread i sent.

Also, just try leaving the clip jumpered and the relay out of the system and take it on a good drive to see what happens---be ready to hook it up gravity fed on the side of the road though if it quits on ya-----nothing you have described points 100% to the pump, which sucks.

good luck again
 

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Discussion Starter #16
Thanks again for the information. I studied your pump thread and have it bookmarked for future reference.
I did bare a spot on each wire, the black and the black/blue wire and wired in a switch. My theory with that was to run it that way. If it started giving me fits I planned on flipping the switch to see if it helped.
I will do some more messing with it tonight and post my results tomorrow.
 

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Discussion Starter #17
I am still stumped.
The other night I fired the bike up and went for a cruise. I had the switch wired in to bypass the relay if it died, but it ran good.
The next day when it was hot out again I fired it up and it ran fine.
After a few minutes of idling in the heat it developed a slight, very slight miss in the front cylinder. It would just pop every few revolutions.
I am turning more to a carb issue, and possibly a pump issue. I will have to check the carbs out and keep a watch on the pump.
Thanks for all the advice.
 

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you say the relay for the fuel pump is $65? if i could see a picture of the relay i could most likely tell you how to wire in a common 5 pin relay from an auto parts store and maybe save you some money....just trying to help.
 
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