Another C24 problem

[IG.]

I did the search and read a couple of dozen threads on the subject, and read the manual. However, I have my own set of circumstances.

I was gonna go riding, and started the bike - on the kickstand (obviously in Neutral), with high idle. After it started, I heard a hesitation for a moment. After that it idled OK. Steady FI came ON, and I checked the code without turning the bike OFF: -C24. I turned the bike OFF. Gave it a minute, and started again. No code.

I let the bike sit for good 30 min. Started again. Steady FI came ON. Checked the code: -C24. Turned it OFF, the ON again - no code.

I have a V-meter permanently connected. Before starting I had 12.6 V. During idle I had around 14V. So, the battery does not seem an issue.

So, it's either the pick up coil (the small one on the side of stator cover), or the bad connection from the coil to ECU, right? So, I will check the connector first as it's the easiest thing to do. If that's OK, I guess I would need to pull the stator cover and take a look at the pick up coil - maybe it got loose or something.

Anyone knows what's the difference between C24, C25, C26 and C27? Same pick up coil is missing 2 or more pulses in sequence per manual. If it's bad connection or coil, this should be random, right?

Also, it seems the problem occurred right at the engine start when the engine is cool, and does not seem to occur on re-start - any meaning to that?

Oh, that's '01 with about 25k miles, PC, Micron full system. No recent mods. I did have sporadic engine cut off in the past months, but replaced the kickstand switch and thought the problem went away. However, I think I still experienced cut of for just a quick moment a few times - not sure.

 

[Haya01B]

C24 is having to do with #1 cylinder coil and the others are for #2-4. It may be the coil that plugs to the spark plug. Try switching it with coil with another cylinder to see if problem moves. If so you have a bad coil. Also check the pins for corrosion and if they are seated properly in connectors.

 

[IG.]

I am confused as to what C24 means. From the diagram it seems that the ECU decides whether and when to power primary windings for each spark plug coil. So, is it also monitoring the secondary windings of the coils (with high voltage), and reports the absence of the voltage? Or when the ECU sends the voltage to a specific spark plug coil it can "sense" that there is an open circuit on another end?

Thanks.

 

[Haya01B]

Good question!

 

[Commuta_Busa]

I don't know how the ECU "senses" a fault with the coils. Based on the electrical diagrams I don't see how it would know what's going on on the secondary coils (high voltage side). Clean all of the connections first including the crank sensor pickup connection first. Then swap coil 1 with coil 4. See if the code changes to c27.

 

[IG.]

OK. Thanks. Will report in a couple of days. Day time job takes too much time, you know...

 

[Commuta_Busa]

I hear that! It always gets in the way but pays some of the bills.

OK. Thanks. Will report in a couple of days. Day time job takes too much time, you know...

 

[IG.]

OK. I swapped coils 1 and 4, and the problem seemingly disappeared. Prior to that I started the bike 3 times when the bike was cool, and every time the code popped up. After the swap, I started 3 times, giving her time to cool down, and there is no code. What do you make of it?

The coil plug looked good. I gave it a shot of electric contact cleaner anyway. The connector on the sparkplug end seemed a bit brownish instead of silverish, and the #4 was the same. Not sure how to clean it, or maybe it's normal.

 

[RYC1966]

could the swap of locations corrected the contact issue?

I do not like elec issues at all...especially ones that come and go. I hope your problem has been solved.

 

[Commuta_Busa]

try swapping them back now. The contact cleaner may have done the trick by itself.

 

[IG.]

I think I've done it, not positive. She is all buttoned up now - too late. Since I was in there, I sprayed connectors for all 4 of them - both male and female, and covered them with dialectric grease. I wanted to put dialectric grease into the spark plug connectors, but the instructions said to only cover the rubber tip of the boot - which I did, as well as the upper part of the boot - for a good seal.

It all would be good.... But, on my test ride to the gas station I picked up a freaking screw - there goes my rear, which is pretty old anyways (installed during summer of last year), but I could get through the winter. Dang!

Well, ordered a set of BT016 for $225 shipped from chaparral. Will plug that rear sucker for the time being.

I am still puzzled where the bad connection was. All coil connectors looked good in the first place. Coils were seated well. I am skeptical there could be a bad connection at the spark plug because a high voltage would go through anyway. Go figure.

Oh, while I was in there, I adjusted my TPS - made a difference in idle.

And since I was working on the bike anyway, I lubed the cables. Also, my clutch fluid was pretty dark, so since I was in a fixing mood, I took out the fluid from reservoir with a straw - a little bit at a time, and added a fresh one. I did change it last year so I know it's good inside the lines.

Dang, I want to ride and not dealing with all this nonsense.

Thanks for everyone's help!