No spark on cylinders 1 and 2

So i just picked up this 1985 xj 700 today with the PO claiming it lost spark after he got caught in the rain last year. He told me he replaced the plugs, plug wires, and coil packs but he still had no spark.

I brought it home and checked for myself, and sure enough I had no spark on any of the cylinders.

I followed along with the forum titled:
How To: Ignition Troubleshooting

until I got to step 3 in the trouble shooting section. I checked for resistance on the safety cut out wire and at first I had a reading bouncing around from around 400 ohms to 15oo ohms. I retried figuring I wasn't making a good connection with my meter where the wire ran into the plug. And to be sure I was grounding I put the other lead on the negative battery terminal. I heard a few clicks coming from the right side of the bike as I was doing this and had no idea what it was since I was only checking resistance.

After trying the same procedure yet again, I was unable to produce a reading on my meter nor was I able to make the unknown component click again.

Again I checked for spark and surprisingly I had spark on cylinders 3 and 4 but nothing on 1 and 2. Being that I was expecting spark on either 1 and 4 or 2 and 3, not 3 and 4, I had no idea what happened.

Any thoughts on what could've changed that made spark on the right cylinders? Did i damage something when I checked for resistance on the safety cutout?

Any help is appreciated!

 

A couple of items to check. Check the ground point on both coils , pull all 4 plug caps, un thread swap plug cap 1 and 4 after you unthread trim a 1/4 " off of plug wire , do the same for 2 and 3 see if you have spark .

 

Make sure that the plug wires are hooked up correctly.
( as you sit on the bike) Left coil goes to 1 and 4. right coil goes to 2 and 3.

It's somewhat likely that a PO messed that up, and that one coil is not connected to the primary, or has failed.

 

I made a little progress tonight. I tried checking for spark after going over the plug wires like you suggested and surprisingly I had no spark anywhere.

I put my meter on the male end of the plug going to the left coil to see if i had power as I was turning it over and I only had 0.5 volts. So I plugged it back together and took the red/white wire off the coil and took a jumper wire from the power input terminal on the coil to the positive terminal on the battery. With this method I was able to manually get spark on cylinders 1 and 4. I did the same with the right coil and got spark on cylinders 2 and 3.

So I want to say I'm not getting power to the coils via the red/white wires like I should. Since i had spark momentarily before I figured this out, I'm thinking its a loose connection somewhere?

Also, slightly off topic question: what type of coolant should I put in this bike?

 

Okay I should have asked is your battery fully charged ? A low battery will cause the TCI to not provide spark below 10 volts

 

And it's not just the state of charge of the battery. The voltage under load matters. A battery can charge just fine, but not perform under load.

Check the voltage at the battery when you're trying to start the engine.

 

It also might be that the sidestand switch is stuck. Peel the boot back, spray contact cleaner into it as you move the plunger. Folllow up with a dry-film siicone lubricant.
If you still have no spark you can temporarily unplug the sidestand relay. It's located under the left side cover, below the regulator, and has a blue paint mark (or a blue locking tab) at the base.

 

I had the battery on a trickle charger over night and had 14 volts when I checked after work this evening. During cranking I have between 11 and 12 volts. This should be enough, right? The bike turns over fine; it doesn't sound like the battery is weak.

If I'm not mistaken, wouldn't the bike still produce spark if the side stand switch were stuck as long as the bike is in neutral?

I still have no power going to the coils. Does the power come from the tci or the ignition switch at the key? I think I need to trace the red/white wire to figure out where things start to go wrong.

 

yes you should have enough voltage to start bike.

ignition fuse is feed by key ignition fuse feeds run/kill switch then from switch it goes to tci and to coils

try disconnecting the black/white wire running from tci it has a bullet connector about 3 inches away from tci.
if starter button is working your problem is from tci connector to coils. only 1 coil will be hot at a time

 

is this a 700n or X
do you have that funky relay combo block

 

It’s a 700X

 

wiring diagram pull in the clutch see if that works

 

I tried it with the clutch in and still nothing. I have about 10.5 volts going into the tci if I put my leads on the red/white and black wires where they go into the plug.

 

is that with starter button pressed and turning over. measure from battery ground and to red white wire

do a voltage drop test hook meter to battery press starter button what does the voltage drop to?

could be you have to clean connectors run switch ignition switch(key)

 

From battery ground to red white wire where it enters the plug for the tci I have between 10.5 and 11.5 volts when it’s turning over.

Voltage drop test: 11.15 was the lowest reading I saw while turning it over.

 

have you disconnected the black/white wire at bullet connector coming from tci?

all voltages need to be measured from battery ground.

 

That’s another issue, there’s no bullet connector on mine.
There’s bullet connectors for a blue wire and a black/red wire but they don’t go to either of the plugs.

 

Now if I got from battery ground to the red white wire where it plugs into the plugs right before the coil, I get 0.6v with the ignition on but not turning over. This is true for both coils and when I do the same set up on the corresponding orange and gray wires.

If I do the same thing when turning it over, it drops to about 0.25 volts

 

I see a black white wire in your photo where does that go?

 

this is the step by step

 

The black wire off the bigger plug is the ground coming off the tci I thought. It goes back up into the wiring harness though on the bike.

The black on the smaller plug I thought was the ground for the side stand relay but that too goes back into the bike with a bunch of other wires.

And then there’s the black white wire on the big plug which similarly follows the other black wire on that plug into the harness.

 

Is it fair to say that because I have very little voltage going to the coils, then the tci is bad? Or are there multiple reasons this could happen?

 

I think we need an X-pert to chime in

 

Oh jeez I was hoping you were the expert.
The good news is I could rig a toggle switch to directly power the coils if I had to. I don’t want to, but that’s a last resort.

 

black wire coming off of little plug is common wire for pick up coils you measure ohms from orange to that black and gray to that black then that black to groung should get no reading with black to ground

the black from the large plug goes to side stand relay (or should) and should have no reading to ground when sidestand is up with bike in gear but read ing to ground when bike is in gear and side stand is down this shuts down motor by grounding out tci

I see a full ground in wiring diagrams but not on tci? does tci mount to a metal plate?

 

I just do not have an X to go look at

find this relay and pull it out
Sidestand (kickstand) relay (blue): under left side cover, above regulator.

this will bypass side stand switch, clutch safety switch, and neutral switch function

 

It doesn’t, and the entirety of the tci is plastic without any type of metal for it to ground on.

Also, with the side stand down and the bike in gear, I have no reading from black on big plug to ground on battery. Everything else though is as you described.

 

Don't wire 12v to the cols you will damage the TCI.

Lets try this...

On the small plug( these go to the pick up coils). Pull it out of the TCI and check with an ohm meter.
Ohm from orange to black it should be about 700 ohms. Not exactly sure what the spec is but they should both be the same.
Ohm from gray to black it should be about 700 ohms
Ohm from any of those wires to chassis ground, it should be open.
It is possible one of the pick up coils is bad.

Next check to see if the black/white wire on the large plug is grounded. Ohm from it to any metal part of the frame. If there is connection then problem found. You can disconnect it or find out which safety relay is at fault. It should measure open with a ohm meter.

With the key on there should be 12v from the red/white wire to the black on the large plug. If not find out why. Could be fuse or bad kill switch

Try these things and let us know your findings , we can do more if these things don't point to a problem.

 

do you get a reading when you pull in clutch?

pulling out the sidestand relay bypasses all the safety stuff and prevents the tci from ground and being turned off

 

no it should read 120 ohms this is an 700 and an X both have 120 ohm pickups

XJ700-X water-cooled models:

Pick-up coils:
120 ohms +/- 20% = 96 ohms to 144 ohms acceptable range


Ignition Coils:

Primary side (input from main wiring harness):
2.7 ohms +/- 10% = 2.43 ohms - 2.97 ohms acceptable range

Secondary side (spark plug wires, without their end caps):
12K ohms +/- 20% = 9,600 ohms - 14,400 ohms acceptable range


Spark plug caps:
1985 XN/XNC models: 10K +/- 20% = 8,000 to 12,000 ohms per cap acceptable range
1986 SX/SXC models: 15K +/- 20% = 12,000 to 18,000 ohms per cap acceptable range


Spark plugs:
1985 XN/XNC models: 0 ohms per plug
1986 SX/SXC models: 5K ohms per plug

 

I have about 120 ohms between black and orange and between gray and black.

With the key off I have continuity between ground and black white. With key on it is open.

And I have 12v from red white to black on the large plug.

 

So far its good. Ohm your ignition coils with the spec XJ550H just posted. You should also have 12v at each coil with key on.

 

You are correct, I did not have my book nearby. My old brain cant keep as much information as it use to.

 

Ok I have 3.0 ohms for the primary. Meter accuracy could explain for the slight deviation from the acceptable range.

When I check the secondary, I’m measuring from plug wire end to ground?

 

Also, I have almost no voltage, about 0.1 volts at the coils with the key on.

 

plug cap to plug cap you are looking for 32k ohms total each cap is 10k plus spark plug wire through coil is 12 k
if reading is off unscrew caps from ends of spark plug wires. do coil separate from caps and caps by them selves

 

check ignition fuse and that run switch is in on position

 

Interesting, I’m getting 16k ohms. Half of what I should have...

 

Ignition fuse is good, I have continuity through it. Switch is in the on position and functions properly.

 

does that include spark plug caps? if so remove them the cap unscrews off the wire

 

No that’s directly from the end of each wire.

 

We are on to something.
With key on there should be 12v on the red/white wire on the TCI and red/white at the ignition coils. Unplug the coils and check the red/white there, should have 12v. If not there is a break n the wire from the TCI to the coils, or bad connection at those coil plugs.
Since you only have .1V I suspect the wire from TCI to coils s broken somewhere in the harness.

 

spec is
Secondary side (spark plug wires, without their end caps):
12K ohms +/- 20% = 9,600 ohms - 14,400 ohms acceptable range

16k is high and out of spec
the spec is for both wires combined they before buying a set of ignition coilsbeginning and end of same wire

it could be your meter touch probes together see what you get.

what do caps measure?

if total wire and caps are added together it may come in spec
measure other coil and compare

I like to buy 1% resistors and measure them to see how close meter comes. remember that you are measuring a coil and its inductance can affect meter reading if you have access to another meter check with that.

 

So tonight I checked continuity between the tci and the coils. My meter confirmed a connection and then I checked voltage and I miraculously had power to the coils. I turned it over and I had spark. I did nothing other than leave the battery on the trickle charger over night. I had 12.5 volts after I turned it over and found spark.

Another odd situation: I pulled the ignition fuse and I still get spark without the fuse in place. Something must be completing the circuit elsewhere.

 

maybe you pulled wrong fuse

 

Maybe messing with the wiring plugs had something to do with it. I would clean the TCI and coil connections.

Or someone has mis-labled the fuses. Has the fuse box been changed? Those old glass ones will give you problems.

 

After a few attempts to diagnose the issue, I finally found a broken wire going to the coils from the stem. It broke in the casing and showed no signs of damage. It was only after I followed the wire and checked voltage every where possible that I was able to narrow it down and replace the broken section.

I have plenty of spark now!

I appreciate any and all help you guys provided!

 

This is a wonderful forum with some truly knowledgeable & helpful members.
Glad you got your spark & you'll love the X.