Rough Idle, Rich exhaust
#1
Rough Idle, Rich exhaust
Just bought a 2007 Road King with 103 cu in engine and EFI. It runs rich and very rough at idle, but smooth at speed.There are black deposits in the exhaust pipes and the lower threads of the spark plugs which imply running rich. It appears to have stock exhaust and air filter. Any ideas? I can find no codes stored in the computer that relate to this, just some maintenance, parts replacement codes.
Doc
Doc
#2
ANY codes should not be there. There is no such thing as "maintenance" codes. What codes were stored in the ECM. I would also look around (under seat) for an add on Piggy controller.
Last edited by Jackie999; 12-28-2010 at 03:03 PM.
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Just bought a 2007 Road King with 103 cu in engine and EFI. It runs rich and very rough at idle, but smooth at speed.There are black deposits in the exhaust pipes and the lower threads of the spark plugs which imply running rich. It appears to have stock exhaust and air filter. Any ideas? I can find no codes stored in the computer that relate to this, just some maintenance, parts replacement codes.
Doc
Doc
Somebody took off their high performance ac and pipes before selling or trading in their bike. You got stuck with stock ac and pipes, on a bike that was tuned for higher flow!
No way a guy will build a 103 and leave the most important parts stock. You are running pig rich, and likely will keep fouling plugs as fast as you can swap 'em.
#6
103 with stock AC and exhaust? Bwaha! I think I have a possible answer.
Somebody took off their high performance ac and pipes before selling or trading in their bike. You got stuck with stock ac and pipes, on a bike that was tuned for higher flow!
No way a guy will build a 103 and leave the most important parts stock. You are running pig rich, and likely will keep fouling plugs as fast as you can swap 'em.
Somebody took off their high performance ac and pipes before selling or trading in their bike. You got stuck with stock ac and pipes, on a bike that was tuned for higher flow!
No way a guy will build a 103 and leave the most important parts stock. You are running pig rich, and likely will keep fouling plugs as fast as you can swap 'em.
A more likely scenario but having the same results would be that the the 103" was a dealer build and the ECM was dealer flashed. Have you checked your mileage? I would bet it sucks.
I think Ed is right on and your best bet would be to install a fuel management system and have the motor tuned. Your idle issue will go away, mileage should improve and generally run better.
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Good call but that would only apply of the prior owner was running a fuel management system that reprogrammed the ECM, like a SERT. However, a SERT or similar system that marries to the ECM/VIN would have no value to the previous owner, but the previous owner may not even know that. On the other hand, a piggy back system, like a PCIII would have been pulled off for reuse or resale and the stock ECM reverted to the stock map.
A more likely scenario but having the same results would be that the the 103" was a dealer build and the ECM was dealer flashed. Have you checked your mileage? I would bet it sucks.
I think Ed is right on and your best bet would be to install a fuel management system and have the motor tuned. Your idle issue will go away, mileage should improve and generally run better.
A more likely scenario but having the same results would be that the the 103" was a dealer build and the ECM was dealer flashed. Have you checked your mileage? I would bet it sucks.
I think Ed is right on and your best bet would be to install a fuel management system and have the motor tuned. Your idle issue will go away, mileage should improve and generally run better.
Odds are he has a flash or a sert program (as you said), either way he's gotta do something.
I agree, no way he'd leave a power commander if he scavenged the other parts. (It would be hilarious if he did).
Simply unplug it. He he!
Last edited by Faast Ed; 12-28-2010 at 04:52 PM.
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I see the reason for a 103 with stock A/C and pipes.
Is the air filter real dirty? Sure does seem like you are running pig rich.
The dealer might have given them and ECM flash because of the added cubes, and the stock A/C and pipes are VERY restrictive.
Sure would be nice if you could have it sniffed, on a dyno to see how rich it's running. Having confirmation is always sweet.
I wouldn't hesitate to put a free flowing air cleaner on there. Obviously you have room to go leaner.
Edit: Still seems the exhaust sensors would be trying to lean it out if they were working.
However, if the base map is super rich, the sensors only compensate a small amount.
I'd still start with a free flowing air filter.
.
Last edited by Faast Ed; 12-29-2010 at 10:56 AM.