Hey guys, I have a 08' Road Glide, just got it about a month ago. In the last week or so I have been getting a lot of backfiring on deceleration, serious lag in the throttle response, and when I'm on the throttle she's been sputtering a LOT. I only use premium fuel and havent run her low on gas.

One source rold me to fill the tank, I was at just over a quarter tank, because I could be sucking air but that didnt change anything. Another source told me to check the plugs and air filter, the forward plug was fouled out but I changed both and she runs the same with a clean filter.

Bike has a stage 1 with 2-1 pro pipe, and there is a PCIII on it. All installed well before I picket it up. I have heard that the PC is a poor tuner, could this be causing the problem? Keep in mind I have none of the adapters to download a tune. I did take the tuner out for a short time per a Technician's advice but that didnt make a difference so I put it back in.

Anyone got any ideas?

 

The PC3 is a great tuner for the time it was made. I have one on my bike and have no issues with it. Could be a lot of things causing this from an intake leak or exhaust leak, bad gas, bad plugs , wires or coil or a bad tune.

Start with the basics and go from there

 

The simple way is to take it to the Harley dealer, and have them connect it to the Scanalyzer. That may tell what is the cause of the stumbling. If you wish to tackle it yourself first. Try these tips:

I would start with the basics first. Check condition of the battery, including a load test. Just take it to the auto parts store, you don't even need to remove the battery from the bike. You will need to remove the seat. Check the condition, and tighten up the battery cables, both ends. Download any historic trouble codes.
If all that tests good, then take a look at the map that is in the PCIII. You will need a USB A to Mini cable, and a laptop. Go to the Dynojet website, and see if there is a canned map that fits the specks of your bike, air cleaner, pipes, cam, any head work etc. There are tutorials there as well. Download any that seem close to the laptop or thumb drive. Load the Dynojet software either on the laptop, or on a thumb drive. Plug the cable into the laptop, and the PCIII. Turn on the bike. The map should come up. Sert the Throttle Postions, both at idle, and WOT. Save the map that you have there, and start loading in other maps to see if they help. If you find one that seems to do better, you can play around with the fuel values in the table. Just remeber to save anything that you may need later.

It also may not have anything to do with the PCII, but something else on the bike. I'd still check out the PCII and the other things I mentioned first.

 

If the bike is just at a stage 1 tune it should run fine without the power commander. Unplug the power commander and ride the bike without it. If it runs better the power commander is the source of your problems; if it still runs poorly you have a different problem.

 

I'll add, I don't know if the '08 models have the issue, but with my '02 if I don't replace the in-tank fuel lines regularly they will develop a leak that will bring on the problems you describe instantaneously. I've also had the TPS go out twice. They didn't fail suddenly but caused erratic running issues for some time before throwing a code. The first I rode about 350 miles home from Florida without getting a code while the bike ran poorly; on the second it coded after about 50 miles. Nothing fails in the driveway.

 

Hey guys,

I’ve got a 2006 Softail Deluxe and it has a Power Commander 3 on it. I’ve noticed that when I really get on it in gears 1 and 2 the check engine light will come on. Also when my RPM’s are below 3k and I hit 5th gear the light will also come on. I’m not losing any power, there’s no noises, throttle response is good but this is driving me crazy. I just bought the bike a few weeks ago in Florida, I have spoken to the gentleman about this issue and he said he never had that problem. Obviously he’s going to say that but I def didn’t get the vibe when I met him or spoke to him he would try and scam me. Has anyone had this issue and or does anyone have an idea of what I should do to correct the issue? Any advice would be appreciated.

 

TUNES DON’T GO BAD.

did you check for codes? Might be really as simple as old gas, might be an intake or exhaust leak. Might be the speed sensor or connectivity. Might be a lot of other things. Check for codes.

welcome to the forum from Illinois (for now).

 

Take the PC3 out of it and see if it does the same thing on the stock ECM without the PCIII playing with the signals.

Personally after I had 2 of them go bad and deemed unrepairable, (but we'll give you a little off on a new one) I went to a Thundermax with O2 sensors and I have never been happier.

How is the idle? Any hints of a vacuum leak where the manifold meets the heads? (use the spray test... spray something like Throttle Body Cleaner around them and if the idle jumps you have a leak)

The bike will run OK without the PCIII with a stage 1 (pipe/air cleaner) mod in order to eliminate the PCIII as the cause.

Take the PCIII out first and see if it goes away, if not look at the plugs... popping on decel can be from being too lean, or being too rich and the fuel is lighting off in the pipes after you come off the throttle. Lean could be a vacuum leak or a bad PC3 not giving it enough fuel, sooty plugs could indicate a rich condition

 

Reading comprehension must be a thing of the past......

 

Hello,

PCIII usb
if the bike runs the same with or withoutthe PC3, it is not the PC3.

Normaly the bike should run lean without the PC3 and more rich with the PC3.
If the PC3 is installed, with a good map, ( for cyllinder back, Fuel Table 1, and cylinder front, Fuel Table 2 )
you should feel a big difference in riding the bike, and no backfiring.

Maybe the bike does not get enough gasoline, the filter in the tank before the pump can be filthy.

ignition cables. ( 8 mm˛)
I measured the resistance, 1 cable was 11400 ohms,other was 7600 ohms, that was a problem.
Replaced them with 10mm˛.( screamin eagle ) and the bike runs fine.