Running Rough, missing/popping

[H2O]

1988 XVZ1300 with 65K mi.

Sat most of the summer, but started it about twice a week.

Started to ride recently. Engine started to "pop" and seem like it wasn't hitting on all 4 until it warmed up. Steadily got worse until one day it just wouldn't start. Acted like it wasn't getting fuel, and it wasn't.

Found fuel pump was not working and replaced it. Started up good afterwards but would not run without missing, coughing or popping.

Changed plugs. Plugs had really carboned up. Put the new plugs in and it ran like it was new! Wow!

Ran about 25 miles. Came home and parked it overnight. Next morning started it and it went back to coughing and popping all the way to work on a cool morning around 58 deg.F.

It was like I hadn't done a thing to it.

Always parked inside. Always run 89 or higher octane fuel. Love my VR. I've owned it for over 4 years and it's never failed me until this issue.

Can I purchase a generic plug wire kit and make it fit?

I've found & printed out other discussions on how to use a meter and test the coils and TCI circuit.

I have removed the fairing, the headlight, the battery, the side covers, the radio/tape deck.

I can see the coils. Where is this TCI thing and how do I remove the seat?? lol

I'm starting to wonder if I should've taken it to a shop!!

Help Please!!

Edited October 3, 2014 by H2O
Type Error

[Neil86]

Are you noticing the tachometer is bouncing around, dipping to zero and back up even though engine is still running somewhat normal?

 

The TCI is mounted on the bottom side of the rack that the 4 ignition coils are bolted

onto., basically above the heatshield atop the front cylinder head of the engine.

[H2O]

No, The tach is smooth and steady. I watched for that.

Thanks for informing me where the TCI is.

[tz89]

Step 1: go ahead and join. Best $12 ever spent, plus a great bunch willing to help.

 

Step 2. Seafoam. If changing out the pump got it to work until the next day, there is probably still a lot of gunk to disgorge. Buy some Seafoam, fuel filters and spark plugs.

 

Step 3. Drain the fuel bowls.

 

Step 4. You need to work a bunch of Seafoam into the system. If you've stripped your bike I would let the fuel pump draw straight Seafoam until the bowls are full then try to start it to get some moving into the carbs. Let it sit over night. Put a Seafoam into the tank. Try to get it running and run it a while. You might need to point a house fan at it to help it keep cool.

 

Step 5. Actually step 2. Read other opinions and suggestions which are sure to be added to answer your question. This is just mine. The clues I'm working off are bike was sitting, fuel pump failed and refailed, fouled plugs. Sounds like a fuel system problem to me.

Edited October 3, 2014 by tz89

[H2O]

Well, I guess the fuel lines could be clogged, but I wouldn't have thought of it.

The fuel filter appeared clean visually, but I didn't change it because it simply ran fantastic when I put the new plugs in.

I occasionally use seafoam in the tank just for insurance.

Now that I've got the bike all apart, do you think I'd be wasting my time testing the coils and TCI with an ohm meter?

 

P.S. And yes, I should've joined years ago when I first found this site, but this bike has been just sooo reliable that I didn't think I would ever be here needing help!!

Thank you for the advice and I will join right away!!

Edited October 3, 2014 by H2O
P.S.

[tz89]

No. While its all apart like that I would do everything you can.

 

Test the coils and replace as need be. Take a good look at the TCI.

 

Plug wires will be easy when it's apart like that. Good copper core wire, resistance plug caps. Just don't lose the cap and o-ring from the coil end of the existing plug wire. You need two straight and two 90 degree NKG plug caps.

 

Heck do the improved ground cable mod. Definitely visit all the cable harness connections and clean and use dialectic grease. All documented on the site.

 

You won't necessarily see gas look like molasses. It's the lacquer that builds up on things when the bike sits. Bad gas can turn to goop or seems like it in the bowls.

Edited October 3, 2014 by tz89

[H2O]

Okay, Thank you for your time and great advice!

[H2O]

Okay, I've gotten to this point.

Pulled the two connectors from the TCI. Printed out test procedure from a previous thread which says to start with the 6-pin connector. Measure the Orn, Gry, Wht/Rd and Wht/grn wires one at a time, which are pickup coil inputs. Should see 115-125 ohms.

 

I'm assuming this means each of those pins to ground, not to each other.

 

When I meter them each to ground I cannot get any continuity.

When I go from pin to pin (the 4 listed above) I get around 215 ohms in any combination.

 

The instruction states that if you don't have this continuity at each pin then you probably have corrosion/failure at a white connector above the stator and they advise to disconnect, clean and test again.

I'm assuming the stator is on the left side, but I ended up taking every white connector apart, cleaned and installed some electrical joint compound off my service truck to inhibit corrosion.

Tested again and I'm still not seeing continuity from these pins to the black grounding wire at the battery. The battery is removed by the way, as well as the headlight assembly and several other miscellaneous connections in the process of taking the fairing and side covers off.

Also, I went forward and checked the 8-pin connector as listed and it appears to be normal.

I forgot to mention,,,, I did check the black ground lead after lifting the battery. It is good and has almost zero resistance to the frame. This is what I'm using as my ground reference.

What am I doing wrong??

Edited October 3, 2014 by H2O
Ground reference

[Neil86]

The 4 pickup coils have a common which is the black on that same connector....it is common for pickup coils NOT motorcycle ground.

The black on other 8 wire connector is ground.

 

so test Orange-Black, Gray-Black etc.

testing color to color will be testing resistance through 2 coils thus results twice spec.

[H2O]

Okay, I've got it. The instruction sheet I printed starts from testing the black wire from the battery to the frame. The next step simply states go to each of the wires listed on the 6-pin connector one at a time and didn't clarify how to do that with two test leads from the meter, or if the test lead at the battery should be disconnected at that time.

 

Anyway, thank you for the clarification. I really appreciate it!!

[GeorgeS]

Have to ask, have you " Synced " the Carbs???

Do you have the tool to do the job. ???

Do you know how to do it ???

 

If not, when you get the tool, one of us here will be glad to talk you thru the job, on a phone call if you need help.

 

Its very important to " Sync " the Carb linkage assembly on these engines !!!

 

Out of Sync, linkage, can cause a lot of problems.

 

But do the Sea-Foam first, as above, Drain each carb bowl, and let pump run some gas thru each bowl.

 

I also suggest you Completely Drain your fuel tank at the Petcock, ( remove hose ) and run a hose from petcock into a bottle, Completely drain it!!! These Tanks Collect Water in bottom, as we NEVER ( well hardly ever ) run them Dry.

 

There might be some very OLD, crude in the tank.

 

Also, run engine at night in dark, check for Plug Wire Arching.

 

Another check to do, is Remove Each Plug Cap, and do a Resistance check thru the cap, it has a Resistor in there, which MIGHT, be OPEN Circuit .

Make sure all for have similar Resistance.

 

On left side of bike, near the fuel pump, find the Large White plug, with 3 #10 wires going thru it,

Open the plug, and inspect for Burnt, or damaged pins in that plug, also pull on the wires, make sure they are crimped in place.

 

Red, Run/Stop Switch !!!! Open up the right handle bar switch housing, and Clean the contacts of the Run/Stop switch. That switch can cause a lot of problems.

 

Inspect your " Ignition Fuse " on the fuse block, make sure the tangs that hold the fuse in place are making good contact .

 

Open up your " Main Fuse " Just to left side of battery, ( Plastic thing with rubber over it ) its a 30 or 40 amp fuse, It has 2 each Phillips screws, holding the fuse element in place , Make sure they are Tight !!

 

Check your battery Studs, They come loose !!!!!

 

Check the Black Battery cable where its connected to ground forward of the water pump, pull that bolt out, and clean up the stud on end of the black cable.

 

( not sure if any of this will cure your problem, but these are ALL, " Good Things To Do " !! and besides, it fun Ha Ha :cool10: )

[H2O]

Since I've taken the bike apart, I've checked almost all of the major electrical connections and terminations, but I did not check the kill switch contacts.

So far the electrical system/ignition system is checking out to be in good condition, and I'll check the kill switch today.

I am planning on spending today flushing the fuel system and replacing the plug wires.

New fuel filter installed last week.

 

I actually have a carb sync from way back.

 

What about the plug wires? Can I buy a generic automotive set locally today or will I have to order an original replacement set?

I thought this would be a quick "seek & fix", and it might have been had I posted questions before I tore into it!

I'm leaning towards the fuel now.

I winterized the bike last November with a full tank and Stabil. Fogged the carbs.

I didn't start it until this spring, and then didn't put but about 20 miles on it all summer, although I started the bike a couple of times a week, planning on riding extensively this fall.

Now I'm down to around a quarter tank of the same fuel from last November.

Anyway, I'm very impressed, and grateful for the help and experienced advice found here!

[mbrood]

I would test resistance from the ignition fuse to the inside of each spark plug holder, looking for about 23K Ohms... 13K for the ignition coil secondary winding and 10K for the resistor in the plug coil. Anything higher talks of corrosion INSIDE the plugholder (you can take it apart and clean) or a bit of green corrosion on the ends of the ignition wire... any green found, snip an 18th inch and reinstall. Any good 7mm non-resistive wire can be used as replacement.

 

I would pull the hose on the output side of the fuel filter and direct the output into a large container so you can turn on the ignition and see pumping volume... Let it settlee and look for any rust bits or water drops in the bottom... then toss all of that "old gas" into your car or truck, refilling your bike's tank with fresh gas.

 

The bike's designed for regular gas, premium blends don't add anything but profit for somebody else. Sooty plugs says you are running rich (initial factory setup) and if they aren't oily or gas wet, you have reasonable combustion. I would still look at getting the carbs synced with a 1K rpm idle setting. There are numerous posts here for slightly reducing the carb diaphragm needle spacer to get a bit leaner mix from about 1500 rpm and up.

 

Mike

[tz89]

There's a pre-made set you can buy on Ebay that I used and so have others with success.

http://www.ebay.com/itm/261611171173

 

 

You can buy the NKG resistor caps and good wire cheap and make your own easily. Don't buy an automotive set. OEM? I guess but why spend more.

 

 

The originals eventually go bad - or not. I had one bad wire when I tested after doing the replacement. Some people just clip the ends of the existing wire and or replace just the caps.

[tz89]

Don't forget to join.

[H2O]

Ignition system checked out okay, but I opened, visually inspected and cleaned every modular plug connection I could find.

Removed the fuel pump and filter and drained out all the fuel completely. Then flushed it out with new fuel before putting the filter and pump back on.

Poured a little Seafoam down the throats last night.

Replaced all 4 plug wires. Removed and cleaned the plugs I put in last week.

I reconnected most of the wiring connections except for the non-critical stuff like the lighting etc.

Put new fuel in the tank. The bike took two hits on the starter button and it started.

I let it run for about 10-15 seconds. It felt sluggish and I shut it off.

Checked for leaks and started it again. This time I used the choke.

It started right up and didn't miss or pop. I turned the choke off and let it run for about 3 minutes then shut it off again. Tachometer seems steady and it's idling around 950-1000 rpm like it always has.

I started putting it back together but ran out of time so I couldn't take it out for a spin yet.

I don't know if any single item was the issue, and I was too impatient to take the time to put it back together after each item check to see if that did it, but it those things probably needed to be gone through anyway like you said.

I have an old mercury filled synchronizing gauge but I haven't used it in over 15 years, but I still have the instruction sheet!

I'm going to try it like it is right now because it ran so well last week after putting the new plugs in. Maybe the bad fuel just fouled them out after a few miles.

The funny thing is the ignition system tested out good, but I had myself convinced I had an ignition issue.

Okay, Okay, I'll get signed up for a membership this weekend. This site has some great experience and advice. I couldn't have located half of those items on the bike much less known what to do with them without guidance.

Thanks for being so gracious with your experience and advice!!

Sincerely,

 

Christopher

[tz89]

Great. I'm glad it's working out. I'd keep Seafoam in it pretty continuously for a while. I would also carry a set of fresh plugs with their gap set. There's a fair chance you will still foul as goop works itself out, and you might as well make it easy on yourself if you are out on the road.

[H2O]

You are a persistent one!!

I did, and not just because you insisted, but equally because of Murphy's law.

Now that I've joined I probably won't have any more issues!! lol

 

Seriously............. Thank you. I appreciate it!

[H2O]

The problem has resurfaced. Haven't been able to put but 4 miles since the last go around, but it's doing the same thing again.

 

I've cleared the fuel issue. Drained tank completely. Replaced fuel pump & filter. Checked fuel pump and it has strong flow. Carbs are getting fuel. I'm not sure it was ever the fuel. At this point, I'm not sure of anything.

The exact same symptom has returned.

 

Now I can only get the engine to idle, and that's around 600-700 rpm. Dies when I try to revv.

 

Pulled all the plugs and left them hanging by the (new) plugwires.

Seeing strong spark on the two right side plugs.

Seeing weak and sometimes no spark on the left side plugs..........both of them.

 

I do have a Fluke multi-meter and can follow procedure for testing the coils, but has anyone ran into this kind of symptom before?

Thanks!

 

At least I'm getting real good at removing and re-installing all the fairing parts and electronics! lol

[bongobobny]

The issue may be the timing pick up coils going bad, or corrosion on the connector for them. Start with an ohms test on them at the connector. The issue could be the TCI going bad as well...

[H2O]

The issue may be the timing pick up coils going bad, or corrosion on the connector for them. Start with an ohms test on them at the connector. The issue could be the TCI going bad as well...

 

 

Okay. I know what and where the TCI is. Are the "timing pick up coils" the same 4 coils that the plug wires originate from below the battery?

[H2O]

The issue may be the timing pick up coils going bad, or corrosion on the connector for them. Start with an ohms test on them at the connector. The issue could be the TCI going bad as well...

 

Okay, I found a service manual on line. I'll start there and see what develops.

Thanks!!

[Prairiehammer]

Okay. I know what and where the TCI is. Are the "timing pick up coils" the same 4 coils that the plug wires originate from below the battery?

 

The pick-up coils are located in the stator cover, where they pickup pulses from the rotating rotor. Those signals are sent to the TCI.

The four coils that are located under the battery (and over the TCI) are ignition coils.

[H2O]

Okay, I read (in the service manual) that the pickup coils are behind the crankshaft cover on the right side.

I removed the large cover right next to the rear brake pedal and I'm seeing what looks like a large flywheel, but no coils.

Is there more to disassemble here or have I opened the wrong cover? lol

The pics I'm seeing on line are really dark and just about useless.

[Prairiehammer]

Okay, I read (in the service manual) that the pickup coils are behind the crankshaft cover on the right side.

I removed the large cover right next to the rear brake pedal and I'm seeing what looks like a large flywheel, but no coils.

Is there more to disassemble here or have I opened the wrong cover? lol

The pics I'm seeing on line are really dark and just about useless.

 

The pickup coils are in the stator cover, the larger cover on the LEFT side of the bike.

The pickup coils look like this:

You apparently removed the clutch cover.

Edited November 1, 2014 by Prairiehammer