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Ignition/Tuner/ECM/Fuel Injection Need advice on ignition issues? Questions about a tuner? Have questions about a EFI calibration or Fuel Injection? Tips on Engine Diagnostics, how to get codes, and what they mean. Find your answers here.
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Old 04-26-2009, 02:07 PM
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Angry Mystery Misfire... fun, fun, fun... NOT!!!

Ok. Fuel injected 06 Night Train...

Once a while back the bike started running like it had no brains right after I started it up and road about 3 blocks. I figure I've got an electrical short some where so I pull the seat, move my heated gloves wire and recover the connector with the supplied plug, and the bike starts up and runs fine. I think no more about it.

I go to Bikeweek in Daytona last month and I ride all the way down there, cruise around, everything's great. I go to Cocoa Beach on a really warm day and park the bike out front of a restaurant while we go in to eat. Come back out and ride three blocks and bam... same crap. I limp down to a gas station, decide to put 2 gals of fuel in it (in case I had some bad gas on the last fill up) and the bike runs normal. I stop at Space Coast Harley and they tell me that it's either that my PCIII has ruined the HD ECM or that I have a hole in the fuel line in the tank.

I ride the rest of the week and then we head back and we stop for lunch in Savanah. Ride three to four blocks and there it is again. Fill up the tank, no more problems. Same amount... 2 gals. So then I get home and test the fuel pressure by starting the bike then shuting it off. Then pulling the fuse for the fuel pump. Then start the bike again... it runs until there is no pressure. I don't figure I've got a hole in the fuel line in the tank.

Next time something happens I am filling up the bike, it's pretty warm out, and when I upright the bike to leave, gas gushes out of the cap.

So here I am, two months later and I ride around town all morning doing errands and I have used only maybe a gallon of gas. Stop at a buddy's house for a while and we go to get lunch and bam... there it is again. This time I disconnect the PCIII and run with the stock ECM and it still runs like crap. I limp back to his house, put the bike in the garage, and we head out on one of his extra bikes (for me) and eat lunch. When I get back, I start my bike and it runs great.

So I ride it home convinced that I have a fuel tank venting problem because it dawns on me that this has happened each time when the bike has been ridden and then left in the sun. I read the shop manual and sure enough, the description of the problem in trouble shooting is right there. So I test the venting and it seems to be all fine. The gas cap sucks but doesn't blow, the vent tube sucks and blows, and the vent hose sucks and blows. I'm wondering if the heat is building up pressure to the point where the tank is like, vapor locked... because the gas cap doesn't 'blow'. (The venting comes through the bottom of the gas cap that I have (flush mount) up to the vent hole in the gas fill tube, and out of the vent tube to the vent valve, etc. and so when the gas exits the vent replaces the lost volume with air through the gas cap.

Anyone have any ideas? I'm trying to go on a trip in mid-may and I've got to get this solved.

Thanks In Advance...

C#

By the way, the bike ran fine this morning... sigh.
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Old 04-26-2009, 05:14 PM
jmetro jmetro is offline
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its not a venting issue, that doesn't affect efi bikes like carb bikes. you might have a clogged fuel filter, or it really could be a hole in a fuel line, you can't check fuel pressure the way you did. you need to hook it up to a guage and run it to make sure it stays at 55-60 psi consistantly. the whole adding gas thing kinda makes me lean twards this, since the fuel pressure will drop off less if the fuel line hole is under gasoline. you could also have clogged fuel injectors.

first thing is to check fuel pressure WITH A GUAGE IN LINE.
that will tell you where to continue, tank or injectors.
i have never seen a pcIII ruin an ecm, but have seen a fuelpak do it. (if disconnecting the pcIII didn't fix it, its not your pcIII, and if the prob goes away ever, its not your ecm)

all in all, my money is on the internal fuel line.
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Old 04-26-2009, 05:55 PM
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Note that I did not add fuel the last time. The line is holding pressure. It is not a hole in the line. Certainly, fuel pressure could be an issue which would be a fuel pump issue, but not a hole in the line. I will check that if I can't narrow it down further. I have a pressure gauge.

The only way that this thing can be that sporatic is if there is something floating in the tank that occasionally clogs the filter to be a filter issue.

If the tank is pressurized the fuel return might not work properly. Once the fuel in the line is spent and fuel is sent to the injectors by the fuel pump, at low speeds the consumption would be low enough that fuel would be returned to the tank. It might take a couple of blocks for this to be the situation.

Failing electronics on an injector with coincidences to riding, stopping, and sitting in the sun could be an issue I suppose, but not a clogged injector I don't think. It's too sporadic.

I should also mention that the ecm is throwing no codes. The connected issue about adding fuel and putting the bike in the garage is that it cools down the fuel that is in the tank already.

C#
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Old 04-27-2009, 10:39 AM
Old Gunny Old Gunny is offline
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You wiggled some wires once and things got better. Look in this area again.
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Old 04-27-2009, 04:02 PM
danfrompa danfrompa is offline
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It's definately a timing issue (sparks). But more I read your story, it's seems to be a grounding problem. W? You said, it is OK for a while if you restart. I say check your grounds... If the fuel pressure had a problem, you will know it by now.... Your bike will run like crap all the time...
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Old 04-27-2009, 05:36 PM
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Ummm... don't know about grounding. See, when I stopped the bike and put gas in it or stored it in my buddy's garage, the tank got cooler. In all cases, the only common issue that seems connected is that I cooled the tank down. It wasn't stopped long enough that it cooled the engine down.

Sure, it can be a wiring problem that just happens to fix itself in concert with stopping the bike for a short duration. The last time I stopped the bike and disconnected the PCIII. Starting it back up did not correct the problem. I also had it fail to correct itself when I stopped it and restarted prior to putting in fuel.

It could be the circuit board in the ECM or PCIII but they are in shade so leaving the bike in the hot sun after it has been running wouldn't seem to be the condition that causes them to fail.

I realize all of this could be a coincidence... but the only thing that is common to the bike starting to run correctly again is cooling off the fuel in the gas tank (thus lowering the vapor pressure). May also be a TS or AS sensor that is flaky... don't know. The troubleshooting list in the shop manual doesn't look like much fun but if I don't fix this I know it will be an expensive wild goose chase at a stealer's shop.

Keep the suggestions coming, guys. I appreciate them.

C#
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Old 04-28-2009, 12:35 PM
jmetro jmetro is offline
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pressure in the tank, will NOT affect pressure in the lines. there is no way the pressure in the tank is exceeding 60 psi, period. there is NO RETURN LINE ON YOUR BIKE! there is only one fuel line leaving the tank. fuel goes from the tank, to a LARGE flat screen, to the pump, through the filter by the pressure relief valve and into the fuel line to the outside of the tank. the pressure relief valve opens at 55-60 psi, bleeding off pressure to the inside of your tank. the pressure in the tank would have to be VERY high to stop this from happening. plus you said the vent was working. so why are you clinging to this theory??


pull the dash off, leave the electrical connected with the fuel level low, and turn on the bike to prime the fuel pump, if fuel sprays anywhere but the pressure regulator, you have a HOLE IN A FUEL LINE., if nothing then move outside the fuel tank. but i bet 100.00 bucks you find a hole between the pump assy and the connector on the outside of the tank.
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Old 04-28-2009, 01:26 PM
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Do you have any fancy spark plug wires? Perhaps they are arcing against the engine. If they are you may notice a burn on the bottom of them. At any rate if you do have fancy ones and you still have the stock ones a cheap experiment would be to switch them back for a while.

Here is a bit more info... Check to see if it sounds like you...
http://hdforums.com/forum/electrical...cm-issues.html

Last edited by TickTock; 04-28-2009 at 01:33 PM..
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Old 04-28-2009, 08:51 PM
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Quote:
Originally Posted by jmetro View Post
pressure in the tank, will NOT affect pressure in the lines. there is no way the pressure in the tank is exceeding 60 psi, period. there is NO RETURN LINE ON YOUR BIKE! there is only one fuel line leaving the tank. fuel goes from the tank, to a LARGE flat screen, to the pump, through the filter by the pressure relief valve and into the fuel line to the outside of the tank. the pressure relief valve opens at 55-60 psi, bleeding off pressure to the inside of your tank. the pressure in the tank would have to be VERY high to stop this from happening. plus you said the vent was working. so why are you clinging to this theory??


pull the dash off, leave the electrical connected with the fuel level low, and turn on the bike to prime the fuel pump, if fuel sprays anywhere but the pressure regulator, you have a HOLE IN A FUEL LINE., if nothing then move outside the fuel tank. but i bet 100.00 bucks you find a hole between the pump assy and the connector on the outside of the tank.
I don't think that you are understanding what I am saying. A hole in the line on the pressure side of the fuel pump would show up by losing pressure into the tank and not providing enough pressure to run the bike without the pump running. That is ONE test that is independent of other possibilities. By disconnecting the power to the fuel pump, the bike would not run because there wouldn't be any pressure due to the leak in the line that is within the fuel tank. You don't need to look at anything to do this test.

The return line for excess fuel pressure does not have high pressure on most fuel injected systems. I don't imagine that the fuel pressure regulator is returning excess fuel to the tank under pressure, but that's certainly possible since I am not an expert on the design of HD fuel injection systems. I have seen enough vacuum created in motorcycle tanks to collapse the top of the tank. The converse could be true, also, and thus the return fuel would not flow back to the tank adequately.

I am not stuck on anything... the simple fact is that this failure has only occured when the bike has been run for a while and then has sat in the hot sun. That is the only issue that has been repeated. So, until the bike fails to run after sitting in my cool garage all night I have to find what the connection is.

You are mistaken, by the way... there is a "return line" on the bike. Here is a quote from the Shop Manual... page 5-49 of the Electrical Diagnostic Manual... "Excess fuel pressure is bypassed to the fuel tank through the pressure regulator". Now, since the regulator is in the tank, there isn't a line technically speaking... there's just a dump. But it shouldn't be 'under pressure'. So if the tank is pressurized, then the return flow >might< be restricted. What would the effect be? I have no idea on a Harley... but I do know that it's not a good thing on a Corvette. So if you're arguing with me because my terminology was faulty, then fine, but if you think that fuel isn't returned to the tank on a fuel injected system then your advice needs some fine tuning.

The problem with assuming that something else is occuring is that most of those issues, other than an electrical one, would not be sporatic. They would be, I believe, continuously a problem. So that would leave an electrical problem that just happens to occur when I ride the bike, let it sit in the hot sun for 30 minutes, and then go on riding wherein in three blocks or thereabouts the bike starts running like crap. Cool the tank off and it goes away. So far, only in these exact conditions has the problem occured.

Yes, I will do a fuel pressure test. I haven't looked at the fuel pump/regulator design yet so I don't know that if a bordeline fuel pump/fuel filter condition would be exascerbated by an increase in vapor pressure in the tank. If the pressure is bordeline, then clearly I need to check the filter and/or the pump. What I am not interested in doing is putting in parts just to see if that fixes it nor am I interested in paying a Harley 'mechanic' to chase a bunch of maybes and ifs.

I hate these kinds of problems... they usually are readily explained after you spend a lot of money trying to fix what the 'experts' recommend and instead its some simple stupid thing.

C#
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Old 04-30-2009, 10:51 AM
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good luck...

Last edited by Gpsjr10; 04-30-2009 at 10:56 AM..
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Old 04-30-2009, 10:51 AM
 
 
 
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