No power to fuel pump

[steveg]

Hello all!

Starting this thread here in the technical section to keep the information where it should be. I introduced myself (and my dad) in the introductions area, and the ball started rolling there.

http://www.nt-owners.org/forums/showthread.php?10432-New-Member-SteveG

The issue is my dad (85 years old) has 2010 NT700V with 22,000 miles that was running fine. Too fine. He never did check and adjust the valves (which he shouldn't have done anyway since they were all in spec, he just loosened up an exhaust valve or two) until now. After putting it all back together, he started it twice and let it idle shortly. Then he lifted gas tank one more time for something (IDK why) and now it won't start. The fuel pump wouldn't make noise, and his checks show that there is no power coming out of the main harness to fuel pump harness.

All fuses are good, and he swapped one of the relays out with the fuel pump relay, no change. The pump is functional, as it works when direct powered. The service manual is at hand.

After reading through the threads here, I sent him the info on checking the MIL light and reading any stored codes. Also learned that the Injector relay needs to be functioning for the pump relay to work. That will be checked also.

I feel that he messed with a connector or wire somewhere accidentally that is causing his headaches, and he is in the process of rechecking all the connections he could have had contact with.

Some good tips were given in the intro thread, and thanks in advance for future help. Nice site here!

Steve

 

[DirtFlier]

What did he do once inside for the 2nd time? I always backtrack my steps when something goes amiss. My guess is that something got unplugged in the process.

 

[Reniram]

Check the easy things first..?? Is the kickstand switch made up.. the on/off switch on the handlebar....the clutch switch ok ??..seems strange that all was well before... it must be something that he moved or pulled to stop it from running....here's hoping!..

 

[steveg]

Thanks for the tips. The easy things have all been checked, and that is why this is so frustrating. Dad reports a little bit of success. Checking for stored MIL codes showed none. While checking the multitude of connections, he found that when he disconnected the MAP sensor the fuel pump would prime when the key was turned on. The bike will start with the MAP sensor disconnected and will idle, but any attempt to give it gas/throttle and the engine stalls. If the MAP sensor is reconnected while the bike is idling, the engine stalls.

So next step (before randomly purchasing the $90 or so MAP sensor) is to find the section in the service manual for testing the sensor. If it tests good, then it sounds like a wiring issue. Will keep you advised!!

Steve

 

[mikesim]

Thanks for the tips. The easy things have all been checked, and that is why this is so frustrating. Dad reports a little bit of success. Checking for stored MIL codes showed none. While checking the multitude of connections, he found that when he disconnected the MAP sensor the fuel pump would prime when the key was turned on. The bike will start with the MAP sensor disconnected and will idle, but any attempt to give it gas/throttle and the engine stalls. If the MAP sensor is reconnected while the bike is idling, the engine stalls.

So next step (before randomly purchasing the $90 or so MAP sensor) is to find the section in the service manual for testing the sensor. If it tests good, then it sounds like a wiring issue. Will keep you advised!!

Steve

Steve:

Have him very carefully check the MAP sensor wiring for any damage/chafing. It is quite likely that during the valve job he pinched the MAP sensor wiring causing this problem. The engine dying immediately after the MAP sensor is reconnected is a good clue. It is acting like the MAP sensor circuit is shorted.

Mike

 

[dnktng]

While checking the multitude of connections, he found that when he disconnected the MAP sensor the fuel pump would prime when the key was turned on. The bike will start with the MAP sensor disconnected and will idle, but any attempt to give it gas/throttle and the engine stalls. If the MAP sensor is reconnected while the bike is idling, the engine stalls.

That is weird. IIRC when I had MAP sensor problems if the sensor was disconnected it gave an instant MIL code 1. I don't recall if some of the multitude of sensors disconnected during the valve checks could accidentally be reconnected to the wrong connector. I thought connectors were different sizes or shapes to prevent inadvertent connecting sensors to the wrong connector, but it may be worth checking. And along that same line of thinking, possibly a vacuum line connected to the wrong location.....but again it would be difficult to do that just because of most hoses won't reach other locations. Pinched vacuum hoses of pulling a hose off is always a possibility. Vacuum hoses problems seems to be a remote possibility since your getting such odd electrical symptoms.

So next step (before randomly purchasing the $90 or so MAP sensor) is to find the section in the service manual for testing the sensor. If it tests good, then it sounds like a wiring issue.

MAP sensor checks are on pages 6-18 thru 6-20, but these checks are based on getting a MIL code first, so your dad will need to figure out which checks will provide any meaningful information.
Since you aren't getting a MIL, I would still be leaning to loose connector, wrong connection, throttle bodies not seated and clamped done with a good seal, Hoses pinched or off, or....??? Good luck.

Just a thought about purchasing parts. Most Honda dealers have a pretty fair return policy on parts not used.....usually meaning parts not opened and <90 days since puchase. I've bought many parts just to have them on hand when going in looking for possible failures only to return the parts if not used. It works better than tearing into it only to not find anything else wrong and decide you want to try a new MAP sensor but have to wait 10 days to get one.

 

[Coyote Chris]

I would think too that if you disconnected the MAP sensor, you would get a trouble code, unless the computer is the issue. But that seems unlikely. This is not a nice gremlin for sure. The computer is very finicky about when it turns the pump on and off, and maybe when it lets the ignition work also....kind of a chicken and egg thing. If your dad did get a trouble code when he disconnects the MAP, then I would say, recheck all connectors, and their pins to make sure they are well and truely connected and check for pinched wires, etc and then start shotgunning the parts. Its hard to treat this like a 1970s machine since it is computer controled. Back then, we asked, "Spark or fuel?" And those systems were linear. Not any more.......

 

[bicyclist]

Seems to me that some time back I somehow got two pairs of connectors plugged into the wrong mates. I noticed the mistake before I put everything back together, so no harm done. You might want to have your dad double check that all of the connectors are plugged into their proper mates and nothing is swapped.

 

[steveg]

Thanks again for all of the input. Dad checked the wiring for the MAP sensor and it all seems good. Still the same in that it starts and idles, give gas and it dies, plug in MAP sensor and it dies. He rechecked the connections, and they are all in the correct spots. Rechecked the MIL codes, and he is getting codes (I don't know what numbers, we didn't talk that long) for the MAP sensor and Throttle position sensor. I ordered up a used MAP sensor on Ebay for a couple bucks, so we will see if that changes anything.

We will get this!! He has to ride it from Connecticut to New Hampshire for Laconia!!

Steve

PS - On a side note I got my '79 CB750F Super Sport project started tonight!!!!! Woooooo WHooooooo!

 

[dnktng]

Just a few ideas.

There is gray 10 pin sub-harness connector located to the left of the throttle bodies that has both the MAP and TPS wiring going thru it. For better ID have your Dad look at page 1-46 of the service manual. He may want to disconnect & reconnect it.

MAP sensor is a 3 pin black connector. TPS is a 3 pin Blue connector. I don't recall if the sensor wiring would even reach the wrong sensor.

Also check that the throttle cables haven't gotten kinked or otherwise changed position and are no longer allowing the throttle bodies to return to idle.

 

[steveg]

Hello!

Time to update. The problem was solved, and then the bike fixed. I am still not sure if my dad is crazy, or sly like a fox.

The solution to the problem ended up being buying a new bike. He must have moped around the house long enough that mom caved in and let him get a new one. He previously had a Moto Guzzi V11 California and loved it, but it was getting a bit heavy for him so he sold that and bought the NT. I guess he never lost the Italian in him, so when he couldn't get the NT running again and got permission (I usually find it easier to ask for forgiveness than to get permission!), he traded the non-running NT in on a 2016 Moto Guzzi V9 Roamer (in yellow!!). I can't wait to ride it!

The fix to the NT ended up being just like dnktng in the post above and bicyclist had previously said. My dad had switched the MAP sensor and TPS sensor plugs into the connector. Even after him saying multiple times that he had checked, rechecked and triple checked the connections. No doubt he will suffer endless abuse from his three sons (all riders) about that!

Thanks for all of your help and patience, and Ride Safe!

Steve

 

[Phil Tarman]

Sounds like your dad is cunning like a fox.

 

[seagrass]

Thanks for the update Steve, it is always good to hear the solution in case some one else has the same problem.

Seagrass

 

[mikesim]

Hmmmmmm...... switch sensor connectors and get a new bike, eh?.........

:wink:

 

[tawilke46]

Hmmmmmm...... switch sensor connectors and get a new bike, eh?.........

:wink:

Wonder if that would work on Linda? And I have two bikes that could both have problems. Gee hon, can I get two new bikes......these just won't run.

 

[bicyclist]

The fix to the NT ended up being just like dnktng in the post above said. My dad had switched the MAP sensor and TPS sensor plugs into the connector. Even after him saying multiple times that he had checked, rechecked and triple checked the connections. No doubt he will suffer endless abuse from his three sons (all riders) about that

Hmmm, that sounds familiar.

Seems to me that some time back I somehow got two pairs of connectors plugged into the wrong mates. I noticed the mistake before I put everything back together, so no harm done. You might want to have your dad double check that all of the connectors are plugged into their proper mates and nothing is swapped.

 

[steveg]

Hmmm, that sounds familiar.

Oops! Sorry for not giving credit where it is due! Edited the update post.

Steve

 

[mikesim]

Wonder if that would work on Linda? And I have two bikes that could both have problems. Gee hon, can I get two new bikes......these just won't run.

If it works with Linda, let me know! I'll try it with Marianne!!!

Mike