Last summer I purchased a V&H Version 1.2 FuelPak and V&H Straightshot HS Slipons and installed them on my 2007 FXDC Super Glide Custom. I also installed a HD Screaming Eagle High Flow Air cleaner.

I installed this equipment with 2,000 miles on the motorcycle and it ran GREAT! Much more torque in 4th, 5th and 6th gears. No complaints whatsoever.

Three weeks ago I had the 10,000 mile service done at Long Branch Harley-Davidson in Long Branch, New Jersey. On the 30 minute ride home, the engine was detonating (pinging) like crazy under medium acceleration in 2nd, 3rd and 4th gears and was STEADY detonating at 70mph, 75mph, 80mph. This had never happened before.

Two weeks ago, I rode the bike on a 100 mile ride and couldn't stand the pinging anymore. Here's what I did:

1. Pulled the plugs. Two things: (a) The rear plug was burning perfect. Nice tan color. The front plug was white - burning way too hot. (b) the plugs had not been gapped by the dealer - the gap should be between .038 and .043 and the gap was .045. I gapped plugs to .040, cleaned them on wire wheel and reinstalled.

2. Put 6 ounces of Techron fuel system cleaner in the gas tank - which was full with 5 gallons of gas.

3. Unplugged, and reinstalled my FuelPak and verified the FuelPak map ( FP-0604).

Then, a week ago, I went for a 400 mile ride in the Pocono mountains in Pennsylvania. Up and down mountains all day - not a single ping. 85mph on the freeway - not a single ping. The motorcycle ran perfectly for 400 miles.

THEN, bike sat for one week. I took out today (October 26) for a 260 mile trip to Cape May, New Jersey and back - and the bike is detonating and pinging all over the place. At 70mph the detonation is constant. And again, medium acceleration in 2nd, 3rd or 4th gears result is substantion detonation

have been using nothing but 91 or 93 octane gas in my bike.

I don't understand how the bike can run for over a year perfectly, then start detonating - then I fool around with it a bit and it runs perfect - and after running perfect, it sits for a week and now it detonates all over the place.

Is this something to do with the FuelPak? My 2007 FXDC Super Glide Custom now has 11,600 miles on it. It seems odd that the front cylinder is running hot and the rear cylinder is not. Also, the power seems fine. It's just the detonation (pinging) that's driving me crazy!

HELP!!!!!!!!

Thanks,
Richard Dondes

 

Other things will cause this as well. Intake leak,(not likely) low fuel pressure, bad injector. The key here is the difference between the front and rear cyls. If that's corrected the ping may disappear. Any connection between a full tank and near empty as to when ping shows up? A basic fuel system check can be performed but won't give a pressure reading. Turn the key on and let the pump run and shut off. Pull the fuse for the pump and start engine. It it starts and quits it's ok. If it won't start, the pressure is bleeding off somewhere and there is a problem. The system should hold pressure for a while with the pump not running, long enough for one start up.
Ron

 

rbabos,

Yesterday, after my 260 mile round trip to Cape May, NJ I pulled the plugs - this was after I made the above post. This time, both plugs were burning the exact same. Both were a very light brown with a little white in the brown.

Any additional insight?

Thanks,
Richard

 

rbabos,

I forgot to answer your question. Yesterday, the pinging occured both when I was low on fuel and just after filling up. The bike ran so good last week in the mountains - this is driving me crazy. The pinging is really loud at acceleration and at any constant speed over 65mph, the pinging is constant.

I will do the fuel pump pressure holding check you recommend and advise the results.

Richard

 

rbabos,

I just did the fuel pump check that you suggested. The engine started, ran for 1-2 seconds, and died since the fuel pump fuse was removed. Did it twice, so it appears that the fuel pump is okay.

Richard

 

The test is not for the pump exactly but the hose from the regulator to the quick disconnect at the bottom of the tank. If have a pinhole in the line, which could happen from the hose rubbing in the tank the line will lose all pressure and the engine would not have started . The end result would be low fuel pressure and a lean condition driving down the road. This checks out ok then. I take it the bike is still operating with the anti knock feature from the factory? Things that will screw with it are the map sensor, resistance change in the wires and plugs that change resistance with wrong gaps or some internal faults. I don't know what resistance checks can be done with the map sensor but the wires can be compared, and plugs replaced. Since detonation rapidly increases head temps and the front plug was leaner looking, which could be from detonation, the problem might be in that wire or plug. Not sure if the anti knock feature will still work on one cylinder only. I do know a simple thing like changing to SE wires will stop the system form working as the resistance readings are not withing what the knock sensor wants to see. It's very sensitive.
Ron

 

rbabos,

I have done nothing to my knowledge that would have disabled the factory anti-knock feature. I have the stock plug wires on the bike that came with it when it was new (now have 11,600 miles). When I pulled the plugs last night, after posting, both plugs were the same - light brown with some hints of white. I cleaned the plugs, as I did after first encountering the detonation 2 rides ago, but have not had the chance to ride the bike today to see if that makes any difference. Two rides ago, lots of detonation - then cleaned and gapped plugs - last week's ride of 400 miles bike ran PERFECT with heavy acceleration up mountains and up to 85mph on freeway - bike sat for one week, then yesterday, bike ran awful with the detonation under all acceleration and constant detonation at anything over 65mph.

Thanks for the brainstorming.
Richard

 

I'd still put new plugs in. Even though they look perfect and seem to work the resistance inside may have changed. Over the years I've even had new plugs fail in high load conditions a couple of times. In the end it still could be the map sensor. Check the plug connector to the unit for corrosion and good contact for starters. I would think a code would be thrown but you never know. I keep zeroing in on some kind of timing contol issue, as in too much advance. Short of that, I'm stumped
Ron

 

Ron,

Well, now I am really confused. Last night I pulled the plugs and cleaned them, verified the correct gap, and reinstalled them. Then, I checked my FuelPak settings, all were okay. However, I re-calibrated Mode 19 (which is what calibrates the throttle to the Fuelpak). Also, I put 6 oz. of Techron in my full gas tank (5 gals).

At 1:45pm Eastern Time today, after doing the plug cleaning, FuelPack Mode 19 recalibration, and 6 oz. of Techron, I took the bike out for a test drive. Here are the results:

1. Hard acceleration in 1st, 2nd & 3rd gears to max speed in each gear: no detonation - not a single "ping"

2. Hard acceleration in all gears, through 5th gear, to 85mph: no detonation - not a single "ping"

Now the bike now runs PERFECT and yesterday it detonated in all gears under any kind of acceleration and at all speeds over 65mph. I have no idea. Can cleaning the plugs fix detonation? Or recalibrating Mode 19 on my Fuelpak? Or putting 6oz. of Techron in my tank?

If I take the bike to the dealer now, it will run fine and they'll find nothing.

I also checked the Diagnostic Trouble Codes. I am getting P1004 for the Electronic Control Module. According the the posts on this Forum regarding DTCs, P1004 for the ECM means "System Relay Contacts Closed." What does this mean?

Thanks, Richard

 

My best guess would be the ecm detected you pulled the fuel pump fuse and threw the code. Clear it and it should go away. If it comes back, worth pursuing. I really can't come up with an exact meaning of p1004 other than the ecm/fuel pump relay thing. The Techron may have raised the octain out of the detonation range, but sitting a week it should still not have pinged on the next ride. Don't think cleaning the plugs, with what little residue on them would make any difference. Wasn't a plug replacement suggested instead? I know how you feel. This intermitant stuff is the worst thing to figure out.
Ron