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Discussion Starter · #1 ·
I have a 2002 VTX1800C just shy of 8000 miles, has an aftermarket exhaust that is very loud, not sure which one and a k&n filter. The bike was running great until we got a couple of really hot days and it started dying at idle and running rough, Sunday morning I went to start it and it was running on just one cylinder and would die if I let off the throttle. I followed the sticky and chased down the grounds and replaced the spark plugs b.c they looked fouled. It ran great for about 20 miles and then started acting up again. dying at idle, jerky(like a miss) at constant speed and to keep it alive at stop lights when I would blip the throttle black smoke was coming out and you could smell the fuel so it’s running really rich. If I got on it, it still ran real good but would back fire a lot every time I let off the gas. What is my next step in trouble shooting this?

I did have the batter replaced shortly before it started acting up. Is there a wire that could have gotten pinched or a vacuum line that got pulled out?
 

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Slayer of Chickens
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Picture? (to identify exhaust)

You are not the original owner? How many miles when you bought it?

Does it have a power commander installed?

When running at idle are you hearing any air sounds near headers (where pipes meet the engine)?

When the plugs were fouled, where they white/ashy or black and oily?

Mort
 

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Pics of the fouled plugs up close would be very helpful. At this point it could be alot of things. I would suspect electrical if it was only running one cylinder, my first thought like Mortikus was if you have a Power Commander installed.
 

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Discussion Starter · #4 ·
Can't post pics yet not enough posts, I don't hear any exhaust leaks or air sound, plugs were black not wet though could have been originals? Not the original owner bought at 7400 probably put 400 on the bike it April and May. No commander that I am aware of or could find.

http://www.google.com/imgres?imgurl...&ndsp=15&ved=1t:429,r:1,s:28&biw=1078&bih=605

It wasn't running bad but just didn't seem to run the same after the battery was installed, I probably should have checked there first anything in that area to look for, normally I would have done it myslef but got a bunch of gift cards from the previous owner with the purchase of the bike.
 

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Can't post pics yet not enough posts, I don't hear any exhaust leaks or air sound, plugs were black not wet though could have been originals? Not the original owner bought at 7400 probably put 400 on the bike it April and May. No commander that I am aware of or could find.

http://www.google.com/imgres?imgurl...&ndsp=15&ved=1t:429,r:1,s:28&biw=1078&bih=605

It wasn't running bad but just didn't seem to run the same after the battery was installed, I probably should have checked there first anything in that area to look for, normally I would have done it myslef but got a bunch of gift cards from the previous owner with the purchase of the bike.
Your problem shouldnt be exhaust unless it started after installing the exhaust. If it wasnt messed with doubt thats it by your symptoms. The fact that is popped up after the battery was changed nearly confirms electrical. I have a 1300 so its carbuerated and obviously a different setup but universally a pulled, kinked, boken, or shorted wire will cause these symptoms. I would check around the battery namely at the wires to the ECM. They often get pulled when the battery is changed.
 

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Slayer of Chickens
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Your problem shouldnt be exhaust unless it started after installing the exhaust. If it wasnt messed with doubt thats it by your symptoms. The fact that is popped up after the battery was changed nearly confirms electrical. I have a 1300 so its carbuerated and obviously a different setup but universally a pulled, kinked, boken, or shorted wire will cause these symptoms. I would check around the battery namely at the wires to the ECM. They often get pulled when the battery is changed.
Bingo, as well as wiring to a PC or aftermarket computer if under there. Tighten those (look for loose connectors near the battery) with a ratchet, not a flat head.

Mort
 

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Discussion Starter · #7 ·
That's what I did last night and I couldn't see or feel anything loose or pinched near the battery, guess I'll dig back in tonight. After looking and shaking all the wires and disconnecting the ecu it ran good until it warmed up again then back to the same old stuff.
 

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Does the oil have a strong smell of gas? If so, quit riding it and check the Fuel Pressure Regulator.
 

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Discussion Starter · #9 ·
Will check the oil tonight, I'm sure it does have gas in it, the cylinders have been washed down with gas and unbunrt gas. Does this thing have a MAF?
 

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Slayer of Chickens
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Yep, BigJon has a good point, it still sounds electrical to me, but if fuel isn't getting to the spark properly, well obviously you'll run into similar symptoms. To hear it function, then not, and have issues with rich/lean on an ECU controlled ride still leans me toward electrical... whether a ground somewhere/broken wire, or simply a failing computer... I've heard similar problems even when an aftermarket computer's connectors were getting gunk in them. Keep us posted with your continued troubleshooting, an experienced eye may see the thread and have a new idea or the right keyword will clue one of us into the problem source or you may just find it on your own.

Keep at it though, once you find the problem, it'll probably be inexpensive to fix and a good half hour of face palming with relief ;)

Mort
 

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Discussion Starter · #11 ·
I got a buddy who knows his stuff coming over tomorrow night to give it a look, like you guys have said it has to be something around the battery but just in case what kind of air flow sensor is on this bike? Are there o2 sensors or is this an open system?
 

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Slayer of Chickens
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I got a buddy who knows his stuff coming over tomorrow night to give it a look, like you guys have said it has to be something around the battery but just in case what kind of air flow sensor is on this bike? Are there o2 sensors or is this an open system?
I don't 'think' so, but haven't really inspected all that much aside from the mods I've done... here ya go: http://hondatech.info/downloads/Moto/VTX/VTX1800/

Download the manual, that link is for your specific model (though all are pretty dang similar). Should help you, and your friend, answer the majority of questions as he gets a chance to help look it over.

Mort
 

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I have an 02 VTX 1800C with just a little over 24K. I was experiencing the same thing found it to be the fuel pressure regulator. A new set of plugs and a regulator later it is running like a dream
 

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Discussion Starter · #14 ·
With the aftermarket exhaust and k&n filter do I need a new fuel maper comander thing? Or should it go back to running fine if it is just a regulator.
 

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I know that it can be a few different things. However, one thing I have seen at the shop on the earlier model vtx 1800 is a bad ground. The ground ran in and was mounted to a poor position by/under the right side cover(if I remember right). Later Honda moved this postion to a better ground. At the shop we have even scraped off some of the powder coat in order to make sure it had a better ground. I hope this helps out in some way.
 

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Discussion Starter · #16 ·
I know that it can be a few different things. However, one thing I have seen at the shop on the earlier model vtx 1800 is a bad ground. The ground ran in and was mounted to a poor position by/under the right side cover(if I remember right). Later Honda moved this postion to a better ground. At the shop we have even scraped off some of the powder coat in order to make sure it had a better ground. I hope this helps out in some way.
I did chase down the grounds like the sticky thread says to and sanded off the paint and greased up the connections so I think I have that part covered. That's why I threw new spark plugs in and thought it was fixed and running great but then it started acting up again 20 miles later.
 

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Slayer of Chickens
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I did chase down the grounds like the sticky thread says to and sanded off the paint and greased up the connections so I think I have that part covered. That's why I threw new spark plugs in and thought it was fixed and running great but then it started acting up again 20 miles later.
That's two votes for the fuel pressure regulator... considering you've done a good deal of electrical inspection... sounds like that regulator may be your next best bet :) Keep us posted!

Mort
 

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I got a buddy who knows his stuff coming over tomorrow night to give it a look, like you guys have said it has to be something around the battery but just in case what kind of air flow sensor is on this bike? Are there o2 sensors or is this an open system?
Like any fuel injected system, it has a MAP, TPS, ECT, AIT and BPS on it. Only the CA models have the O2 sensors in the exhaust. You'll see it, if it's there. With the aftermarket stuff, a fuel chip might be useful. Rule out the FPR before you spend more time chasing an electrical issue, and change the oil & filter...get the gas out of there.
 

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Discussion Starter · #19 ·
99% sure it's the pressure regulator, pulled the breather hose off and hit the on/off switch and fuel came out, and my oil did have a heavy gas smell. New regulator should be in Friday, will do an oil change and spark plugs at the same time. I will let you all know if that fixes it.
 

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Discussion Starter · #20 ·
Put in the fuel pressure regulator and that seem to do the trick. It doesn't seem to have quite as much pull as it did before when it was dumping fuel, do I need a fuel comander or that new cobra fi2000 powrpro tuner?
Thank you all for your help
 
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