Author Topic: I've got a head scratcher... (Read 4984 times)

Elliotthd · **on:** April 22, 2015, 02:30:53 pm

Good morning everyone. I have a 2013 C5 Classic. It has a Nfieldgear EFI Muffler, K&N Air Filter, and a recently installed PCV. Since installing the PCV the bike has been running wonderfully, and I've been enjoying the back roads and sides streets more than ever.

Now for the head scratcher part. Last night I had to take a short trip from Philadelphia PA to Wilmington DE and i was in a hurry, so I-95 was the road of choice. This was the 1st time I've been on the highway since I installed the PCV. As I was cruising at around 65mph on the clock, I kept having an intermittent miss. Like a quick stall out every so often. Same thing on the ride home. Cruising along at 65, then miss, cruise along, miss. I tried slowing down to 55, same issue, then I punched up to 75 and same issue. I thought maybe it was the plug, but upon inspection when I got home, it looked perfectly healthy.

I rode to work today and had no issues or miss fires, but my ride to work is stop sign to stop sign, so I never get out of 3rd gear. Anyone have any ideas why I'm getting miss fires, or at least what feels like miss fires, at sustained cruising speeds?

NField Gearman · **Reply #1 on:** April 22, 2015, 02:37:55 pm

I'd check the MIL system for a code. It's likely that it's not related to the power commander at all and something else entirely.

Elliotthd · **Reply #2 on:** April 22, 2015, 02:42:47 pm

I'll check it, but the Dummy Light isn't on.

Also, I left this part out, I did reach down and push the plug wire down on the plug while riding, just to make sure it hadn't come loose, that did not fix the issue.

Elliotthd · **Reply #3 on:** April 22, 2015, 03:00:43 pm

I've got no codes.

John20121978 · **Reply #4 on:** April 22, 2015, 03:09:36 pm

My 2012 c5 is doing the same thing. No codes either.

High On Octane · **Reply #5 on:** April 22, 2015, 03:20:43 pm

I would be taking a look at the negative battery cable. They are known for breaking under the insulation and causing random misfires.

Elliotthd · **Reply #6 on:** April 22, 2015, 03:23:17 pm

Yeah, I've fixed mine maybe 15 times now. It just a bad design. I guess I'll check it again. That hadn't occurred to me, since the most recent fix seemed to be holding when I installed the power commander.

Elliotthd · **Reply #7 on:** April 22, 2015, 03:36:44 pm

Everything looks intact here, though being at work, I can't tear it apart and really inspect it. I'll have to check it out when I get home and see if maybe the cable end is loose on the wire. I have a feeling that you're correct about this Mr. Octane.

gashousegorilla · **Reply #8 on:** April 22, 2015, 03:43:51 pm

Quote from: Elliotthd on April 22, 2015, 02:30:53 pm

Good morning everyone. I have a 2013 C5 Classic. It has a Nfieldgear EFI Muffler, K&N Air Filter, and a recently installed PCV. Since installing the PCV the bike has been running wonderfully, and I've been enjoying the back roads and sides streets more than ever.

Now for the head scratcher part. Last night I had to take a short trip from Philadelphia PA to Wilmington DE and i was in a hurry, so I-95 was the road of choice. This was the 1st time I've been on the highway since I installed the PCV. As I was cruising at around 65mph on the clock, I kept having an intermittent miss. Like a quick stall out every so often. Same thing on the ride home. Cruising along at 65, then miss, cruise along, miss. I tried slowing down to 55, same issue, then I punched up to 75 and same issue. I thought maybe it was the plug, but upon inspection when I got home, it looked perfectly healthy.

I rode to work today and had no issues or miss fires, but my ride to work is stop sign to stop sign, so I never get out of 3rd gear. Anyone have any ideas why I'm getting miss fires, or at least what feels like miss fires, at sustained cruising speeds?

Interesting. It's not the first time I have heard that . I would check your map and make sure it is the one for your bike. You can also try unplugging the PC-V , put it back to stock . Then see if the problem goes away at high speed/ high revs.

cstorckiii · **Reply #9 on:** April 22, 2015, 04:11:59 pm

I put my PCV on in November, and was having the same issue. For unrelated reasons, I spent the last month tearing down and rebuilding my engine. I also took the opertunity to decarbonize the head, piston, and cylinder. I've had the bike back on the road since Friday, and it has been running flawlessly. You may have enough carbon on your piston crown to create a slight over rich condition. GHG, am I thinking in the right direction?

Elliotthd · **Reply #10 on:** April 22, 2015, 04:19:00 pm

Ugh, don't tell me that. I didn't expect to have to tear this motor down for any reason at all for like 30,000 miles. I'm gonna pray that it's the negative battery cable for the 100th time in 2 years and go from there.

johno · **Reply #11 on:** April 22, 2015, 04:24:41 pm

What grade and manufacture of spark plug are you using?
This may simply be an overheating plug issue........

gashousegorilla · **Reply #12 on:** April 22, 2015, 04:43:08 pm

Quote from: cstorckiii on April 22, 2015, 04:11:59 pm

I put my PCV on in November, and was having the same issue. For unrelated reasons, I spent the last month tearing down and rebuilding my engine. I also took the opertunity to decarbonize the head, piston, and cylinder. I've had the bike back on the road since Friday, and it has been running flawlessly. You may have enough carbon on your piston crown to create a slight over rich condition. GHG, am I thinking in the right direction?

I think you might be. And I hear ya about the possible condition of the chamber BEFORE the PC-V is installed. I have seen some pretty badly carbonized chambers and piston crowns... leaking valves and such. But , that may have to do with the very low compression and possible leaks at the exhaust port/ header connection. At least as far as carbon goes. But.... Where I heard about this issue before. There was not a lot of miles on the motor. So I'm, not sure.

And I wouldn't make the Jump to that yet.. although you may be right. I think the simple first step would be to plug that PC-V into a laptop or PC. Make sure the right map for the bike is running. And/or also simply unplugging it and see if the problems goes away.

NField Gearman · **Reply #13 on:** April 22, 2015, 04:57:17 pm

Could also be the sidestand switch. Those like to make it sputter at higher revs.

Vince · **Reply #14 on:** April 22, 2015, 05:35:29 pm

Yes to checking the negative battery terminal and the side stand switch.
Also, change the spark plug. The stock Bosch is really not that good. The NGK BPR6ES is MUCH better. No matter what plug you use, mostly going at low speeds/low RPM will foul it. It may look OK, but there can be enough of a baked on coating to inhibit spark. It is a cheap and easy check that fixes most of these types of complaints.
There is also a possibility of some water in the gas. Over night a half filled tank can have enough condensation to seriously impede running. Dump in one ounce per gallon of gas of any product the "Cleans your fuel system as you drive" or "Removes water". They all work the same way. The chemicals break down the surface tension of the water so it can mix with the gas and pass through the jets or FI orifices. Untreated water is too dense to pass through the same small holes as gas, so it will block off fuel flow.

Elliotthd · **Reply #15 on:** April 22, 2015, 06:00:35 pm

7800~ Miles on the ODO.

PCV was the premapped for the K&N and aftermarket exhaust.

Full tank of gas, filled before I left the city and got on the highway. 95 Octane Sunoco.

NGK BPR6(r)ES is the plug I'm running. I was thinking of going to a 5.

My steps after work are:
1. Stop and grab a new plug and cable end on my way home.
2. Put a chain and a back tire on my buddy's Triumph, and get that out of the way.
3. New plug and battery cable end on Enfield.
4. Test drive.

Hopefully the problem is solved and I don't have to do anything else. I'll report back. I really do feel like it's the battery and nothing over complicated.

pmanaz1973 · **Reply #16 on:** April 22, 2015, 06:51:05 pm

+1 on side stand switch neg. terminal and plug.

I had a small crack on the insulator of one of my plugs on another bike and it acted in a similar fashion. The crack was so small that I couldn't see it without magnification.

What ever you do, don't change everything at once. I'd start with negative terminal (inspect) and side stand switch (remove) then run it and see - good gas treatment, run it - then plug, run it, etc. I've seen a lot of guys throw a ton of fixes at bikes that only really needed some basic trouble shooting and patience to fix the issue. Almost always it is the simple fix that cures it.

Good luck

Elliotthd · **Reply #17 on:** April 23, 2015, 06:21:15 pm

Just an update. That triumph took much longer to get done than expected last night. The old tire just did not want to come off the rim. It ignored all cursing and insults thrown at it, and simply would not bend to my will. It did however, bend to the will of the saws all.

I just had a paying customer drop his bike off for a spring tune up/gas leak and alternator issue, so that is now priority over my own stuff. As soon as I have a chance though, I'll be running the balls off my bike with the negative battery lead replaced (again) and a new plug and I'll let you all know if the problem has been corrected.

Arizoni · **Reply #18 on:** April 23, 2015, 08:46:13 pm

If it's still connected, unplug the sidestand safety switch.

Just follow the wire from the switch to the area behind the engine and unplug the connection.

crock · **Reply #19 on:** April 24, 2015, 01:56:19 am

Great suggestions here.

Elliotthd · **Reply #20 on:** April 27, 2015, 02:44:43 am

It was the negative battery cable. Again! I went to pep boys, bought a copper, solder on, cable end and soldered it on. Also, rerouted the cable so it attaches at a better angle. No more missing. Hopefully this is the last time i have to do this.

High On Octane · **Reply #21 on:** April 27, 2015, 11:15:08 am

Good deal, glad your up and running again.

Elliotthd · **Reply #22 on:** April 27, 2015, 12:53:32 pm

Yeah, thanks man. I would have never thought of that since, like I said earlier in the thread, it was in good shape when I installed the PC. And the fact that I've fixed that particular issue several times over the last few years, two and two weren't making four. But as sson as you said neg... that light bulb lit up like a firework. Mr. Octane, and everyone else, i appreciate the help and suggestions.

dickim · **Reply #23 on:** April 28, 2015, 07:09:30 am

What a great site - was aware of poss misfire issues somewhere in my brain, but forgot ! Has a couple and as I was intendening fitting an NGK - did so & Bosch was sooty! Started great but on 1st "real run" to a winery with new girlfriend on the back she (the bike!

) started missing....hmmmmm. Then remembered this thread & checked the Neg lead to find it COMPLETELY fractured at the bend in the copper !!!! only running due to it resting on itself.
So cut off and crimped a new one on, also rotating the captive but to make it a top mount

Royal Stargazer · **Reply #24 on:** May 08, 2015, 04:04:04 pm

I have almost the exact same setup (2012 C5, almost 8,000 miles, PCV, EFI silencer, NGK plug) and I'm having the exact same problem. In fact, I was about to post a similar thread just now before I stumbled on this one.

I'll be disconnecting the side stand switch before my ride home today and hope that does something. Earlier this week I switched plugs, ran some fuel injector cleaner, and checked every connection for fit and that alleviated the problem... Until this morning.