99 X1 Ignition Problem

[mstrfrz]

99 X1, VDO Race ECM, 365k miles. Rear cylinder misses. I can pull the wire on the rear cylinder and the bike continues to run on the front. Reversing the process, and it dies. It's been going on for quite some time, but lately getting worse. Wiring looks OK, new plugs and wires. No noticeable change when I put the stock ECM back in. HELP!!!

 

[mstrfrz]

Sorry, 36.5k miles.

 

[ophawk]

Have you tried to switch the terminals on the coil to see if it will then run on the rear?
If it does i would highly suspect the coil being bad. other than that, it could be a fuel injector issue.
Later,
Dale

 

[mstrfrz]

Which terminals, exactly? I do suspect it, but isn't a coil an all-or-nothing part? The rear cylindar fires MOST of the time... Can injectors be swapped?

 

[ophawk]

the actual terminal for the plug wires. yes the coil is one unit firing both plugs each time, and if one side is bad the unit would need to be replaced.
yes the injectors can be swapped also.
let us know
later,
dale

 

[mstrfrz]

I didn't know both cylinders fire simultaneously. If that is the case, you'd expect similar performance from each. Off to check...

 

[mstrfrz]

Well, they obviously don't work that way. I got a few impressive backfires, but that's all. It'll be a day or so to swap injectors.

 

[ophawk]

unless the ignition system has been changed they do work that way, the Sportsters and Tuber Buells are a simple system, they fire both plugs each revolution one for the TDC compression, the opposite cylinder is during the exhaust stroke and is wasted.
Later

 

[ophawk]

never mind I just re-read the original post, concerning the Race ECM, that would change everything if it was changed over to a Single fire system.

One other place to look is the timing pickup sensor, as that controls the actual firing time for each cylinder, if the sensor is not receiving a signal for the rear cylinder, that would cause the same symptoms you have stated.

sorry for the confusion.
I can be Slow sometimes.
Dale

 

[mstrfrz]

The manual says non-waste spark. Problem is intermittent. I'll explore the wiring from the pickup to the coil...

 

[mstrfrz]

OK, swapped injectors. No change. Isn't an ignition coil an 'all or nothing' part? Since it does fire both cylinders, the culprit would be the ignition pickups or wiring between?

 

[ophawk]

yes you would be correct, it fires when it get the signal. so the pickup sensor/wiring would be the next logical place to look for this problem of one cylinder firing and the other not!

 

[kbaddict]

Just a suggestion. Check your engine temp sensor. I had an 01 x1 they acted like it had an ignition problem that got worse and worse. I eventually took it in because I couldn't figure it out. Turned out to be a faulty sensor. I also had a race ecm on it.

 

[kbaddict]

If I'm correct, isn't the temp sensor on the rear cylinder?

 

[kbaddict]

The ET Sensor provides the ECM the current engine temperature. Proper fuel and spark delivery are dependent on the temperature of the engine. The ECM will provide a richer fuel mixture on start up and a higher degree of spark advance. As the vehicle warms up to operating temperature the fuel mixture will lean and spark advance will decrease.

 

[mstrfrz]

Hmmm, how would I test that sensor? I've got new problems now. My clutch (I hope) needs replacing. Is that right @ 36.5k miles? It runs roughtly (bucks and kicks) off a stop and I can rev the engine in gear...

 

[ophawk]

The Clutch may just need to be adjusted, I have nearly 70k miles on mine without an issue.

 

[kbaddict]

I'm not really sure how you could check it. I would start by locating it and checking the wiring for shorts. I don't think the part is expensive so you might try replacing it if it's cheap enough.

 

[mstrfrz]

clutch ok, lost 1/2 the teeth on my belt, though.

Anybody got a part # on that sensor?

 

[kalali]

A couple of things. I've never heard of a VDO Race ECM for an X1 so I assume you're talking about the Buell Race ECM. Now, it sounds like regardless of the ECM you have an intermittent spark on your rear cylinder. Did I get it right? First of all, when you say the "wiring looks OK" if you mean visual inspection, then that counts for nothing. You can't tell a bad plug wire from a good one by just looking at it unless you have superhuman power. Do youself a favor a get a shop manual and a voltmeter. Or just go ahead and replace the wires. They cost about $3 each. Once that is done and the problem is still there,, let us know we go from there...