Starts, dies.

[Puddlejumper]

Have been going by the trouble codes being given. Had not thought it might be another sensor. Will try the wire Greg suggested and hope that will allow the bike to continue running and not die. If so, then I will agree I have a wiring problem, which right now due to continuity test that I have already done, does not indicate open wire. Do hope it is not a bad ECU, and if wire continuew to check out ok, I will take Ross up on his offer, take my ECU and see if his bike continues to run with my ECU. If so that should tell me what I need, I think?????

[muz]

Diagnosis by substitution, why not. Hope it works out for you. You are fortunate to be able to do it but if it does turn out to be the ecu you would have to be real unlucky. In my experience ecu's rarely die through natural causes. Another one to check if you haven't already done so is the frame earths especialy the earth going to the ecu. Clean and tight. Check the electrical pdf for their location.
Good luck, keep posting.

[ppgflyer]

Roger.

Here is my set-up for measuring the VDS sensor voltages.

Turn on ignition, FI light goes off after 3 seconds, fuel pump stops afte 5 seconds. VDS voltage initially 0.88v, drops to 0.76v when fuel pump stops.
If VDS is tilted then voltage goes to 4.3v and remains there until VDS is reset by cycling the ignition. FI light remains on until VDS is reset.

VDS disconnected produces 5.0v on the sensor wire, this voltage is generated by the ECU. FI light comes on indicating a fault.
Reconnecting the VDS restores 0.76v and after about 12 seconds the FI light goes off indicating the fault has cleared.

Rapidly making/breaking the VDS connector results in a fluctuating sensor voltage as it climbs to 5.0v when disconnected but is then sent lower by reconnecting the VDS sensor, if it's disconnected for about a second the FI light comes on but then quickly goes off again when the VDS is reconnected.

With the engine running and the VDS sensor disconnected for less than a second it does not result in any engine hesitation, only when the FI light comes on does it quit. If the circuit is remade the bike can be re-started without recycling the ignition, even when the FI light is on - after 12 seconds the FI light goes off provided the VDS voltage is within specification. I was able to make the engine hesitate but still keep running, if this were on the street at 40mph the momentum would keep the engine running and this would feel like a hesitation.

[ppgflyer]

Roger, just reading back through your posts, #94 & #99. The voltages should be the same but they are not! It looks like a high resistance contact causing elevated voltages at the ECU, high enough to cause the ECU to think there is a problem in the wiring. The most likley cause of a high resistance contact is going to be the pin contacts in either the VDS connector or the ECU connector.

[NogiRider]

Has the problem been fixed? The same thing happened to me this weekend. I arrived Sunday night from Hermosillo, Sonora. Monday morning start it up to leave for work and it died several times. I adjusted the throttle cable and it fixed the problem.

[Puddlejumper]

No, not fixed as of yet. Will have to wait for a couple weeks, as I am going on a trip. Will work on it after I get back. I do not think my problem is a throttle cable. Did you adjust the actual throttle cable or the idle cable? I have already adjusted the idle cable, did not change anything.

[NogiRider]

It was the idle cable located under the right air cleaner cover. I rotated it about a quarter turn clockwise. Good luck to you man.

[Puddlejumper]

Hey fellows, back home now and will be working on the bike again. Reading all the posts again, as I have forgotten a lot of what has been suggested. Greg, I will be using a seperate wire to test the center wire back to the ECU. BTW, it looks like your VDS is under the seat on the 1500. Mine is under the frame under the fuel tank. Have to lift the tank just to do my testing. Any way I will test that wire this weekend and then go from there. Ross, if bike continues to die after testing wire with alternate wire, does offer still stand to bring my ECU down and test in your bike? Thanks guys, and will post results soon.

[ppgflyer]

Welcome back, I trust your trip was an enjoyable one?

Yes, my VDS is just in the frame at the front of the seat, remove the battery bracket then the VDS bracket and it comes out easily, if you have to lift the tank that's a pain. Look forward to hearing some good news soon.

[Puddlejumper]

Yes, trip was great, weather good, temps in the 80's. Will be posting again as soon as testing is complete.

[Puddlejumper]

Hey guys, working on trouble again. Checking voltages at VDS, and disconnected VDS to do voltage check. Voltage at VDS connection and at ECU is 1.57 VDC. The interesting thing is I cranked the bike and it sits and idles until I reconnect the VDS. What is the deal, that it will not run with sensor in place, but will with sensor disconnected? Any thoughts, and does that indicate that I might have a defective ECU? Thanks

[Puddlejumper]

OK, some more information. With bike idling, and VDS disconnected, voltage on the center wire of the VDS connector is 1.68-1.70 VDC measured at the ECU, and at the connector. When VDS is reconnected voltage drops to .76 VDC, bike misses and dies within 15 seconds. Tried this three times, with same results, and then tried with the new sensor I purchased with the same results. When sensor is disconnected and bike is running, do not have FI light on. When bike dies with sensor in place, and bike is recranked, FI light stays on. Next question, if this sensor is just to shut fuel pump off when bike is down, what, if anything, would it hurt to run the bike without this sensor?

[Rasta]

I don't see what it would hurt. I would run without it and see what happens!

[kmaysob]

the sensor is strictly there for if the bike is dumped. when on its side, it will starve for oil

[Puddlejumper]

Answering my own question about riding bike without sensor. Probably would not hurt if bike would run. Got bike back together yesterday and tried to start, would not start. Fuel pump would not cycle. Tried again this afternoon after church, pump would not activate with sensor removed. Lifted fuel tank, replaced sensor, pump cycled as it should, so I guess this sensor completes a circuit which tells the pump everything is ok to send fuel to the injectors. Now I am back to the original problem that bike dies within a few seconds after starting. OH WELL, continuing testing. Have a great day all.