Throttle problem

Sitrep05Sep07:
esteeryder, unfortunately it's not from over oiling the K&N.

I got another ECM from a fellow board member today. He tried mine out on the West coast at 104-106 deg and 108 miles and his ST ran fine. Although he may have melted a little!

I installed his "good" ECM and went for a ride. Long story, here is the short version, I still have the same problem in 75-80 miles.

Well we have eliminated one more component. Only a few more to go: coils, CKP (tells engine RPM), CMP (tells firing order), TPS, and knock sensors.

I'm going to try and talk the Dealer into springing for a set of coils and the CKP.

I have a replacement MAP sensor, that will go in tomorrow after work.

Time4Sleep
Neil S.
 
ccryder said:
BBY:

The fuel mileage drops into the 18-21mpg range when she is acting up.

MPG going down could indicate too much fuel or improper ignition. Am I thinking correctly here?

Thx
Neil S.
Click to expand...

I know it is of no help to you as you have already investigated this aspect to death, but for documentation sake, my real time mpg read out was dropping like yours when I had a vacuum leak!
 
MidLife:
2 weekends ago I replaced all the vacuum lines and fittings.

Update 06Sep07:
My Service Mgr is coming through. We are going to try the Pulse generator, at the front of the crankcase. If that doesn't work he will have 2 coils and a fuel pump assy. available. He will call when all the parts are in.

Our game plan is for me to ride down and try and get Indigo to act up. Quickly swap out the Pulse Generator and have Neil test ride Indigo to see if she acts up again. If she acts up then swap out the other components.

It's a plan. He feels the PG is a likely candidate since it will not produce a fault code if it acts up. It also has been R&R at least 3 times during the 3 water pump R&R.

The coils will only produce a fault code if the primary side acts up. If the secondary side acts up, no code is produced.

Hopefully next week the parts will be in and we will be off investigating Idigo's ailments.

Time2Go

Neil S.
 
Er, ahh, well, maybe, but no. :eek:

Do I have to use Honda wire or can I substitute generic wires. Can I snake them through without removing tupperware? Maybe just raise the tank and remove the top bolt through the vent in the middle cowl?

See this is why I need the help of all you riders out there. :bow1: Sometime I can't see the nose on my own face LOL! :rolleyes:

Neil S.
 
Hey Neil,

If you have the service manual, check out the TB sync procedure. At the start of that procedure, they tell you how to bypass the MAP sensor so that the engine can run normally with vacuum line and pair valves disconnected. The value of this in your situation is that you can use this procedure, bypass the MAP, and see if you are able to duplicate the problem while the MAP is bypassed. If the problem happens while you have the MAP bypassed, then you know that the MAP sensor is not the problem AND you know that the problem is not vacuum-related.

If you still can't find your service manual, give me a call this evening and I'll pull mine out and walk you through it. If I recall correctly, it's just something like hold the RPMs up above 2k or 3k for 2 minutes, but best to read it and be certain.
 
One possible way to help with the diagnosis: When it acts up, pull over, and see what your idle is doing. If your idle is rough, then this would be a good time to pull one plug wire at a time to isolate a bad plug or coil wire. Use something insulated otherwise you may get a nice jolt. Pull one wire at a time, when you pull the one plug that doesn't change the already rough idle then that is the culprit cylinder.
 
Just a note that Roger (esteerider's) suggestion will not work on the ST1300. The ST uses a distributorless "wasted spark" ignition system in which paired cylinders, 1-3 and 2-4, are each sparked by one coil, the spark traveling through both cylinders; it ignites the mix in the one that's TDC compression and is wasted in the one that's TDC exhaust. If you pull the igition wire off any plug, you'll also lose its twin cylinder as the spark circuit is now interrupted and both cylinders will drop out.

Just thought I'd mention this as a sort of refresher. :)

Pete
 
karaszp said:
Just a note that Roger (esteerider's) suggestion will not work on the ST1300. The ST uses a distributorless "wasted spark" ignition system in which paired cylinders, 1-3 and 2-4, are each sparked by one coil, the spark traveling through both cylinders; it ignites the mix in the one that's TDC compression and is wasted in the one that's TDC exhaust. If you pull the igition wire off any plug, you'll also lose its twin cylinder as the spark circuit is now interrupted and both cylinders will drop out.

Just thought I'd mention this as a sort of refresher. :)

Pete
Click to expand...

Really?
Do I understand this correctly: You pull a single plug wire and that interrupts the spark to the other spark plug?

Mark
 
Pete, I understand what you are saying about the shared coils, and you may be correct, but to my knowledge most modern multi-cylinder bikes use shared coils and I find it hard to believe that if one plug were to quit working either thru fouling or being disconnected that both plugs become inoperative.

Any electrical engineers out there?
 
Let me try and walk you through this.

The spark is produced between the two ends of the secondary windings of the ignition coil. One end of the coil is hooked to (say) cylinder 1, the other to cylinder 3. Now we know that the spark travels from one end of the coil to the other. Let's say it goes down the center electrode of plug #1, jumps to the ground electrode, travels through the head, jumps from the ground electrode of plug #3 to its center electrode and travels through the wire back to the other end of the spark coil. If this path is interrupted, there will be no spark in either cylinder.

Because the spark always jumps from ground to center of one plug in the set and center to ground of the other it creates uneven wear of the electrodes, so those of you who use platinum tip plugs and don't change them for 100K miles or more, would do well to switch the plugs around in the cylinder pair every 16K miles or so. Of course if you use ordinary plugs and change them regularly this is not an issue for you.

Pete
 
karaszp said:
Let me try and walk you through this.

The spark is produced between the two ends of the secondary windings of the ignition coil. One end of the coil is hooked to (say) cylinder 1, the other to cylinder 3. Now we know that the spark travels from one end of the coil to the other. Let's say it goes down the center electrode of plug #1, jumps to the ground electrode, travels through the head, jumps from the ground electrode of plug #3 to its center electrode and travels through the wire back to the other end of the spark coil. If this path is interrupted, there will be no spark in either cylinder.

Because the spark always jumps from ground to center of one plug in the set and center to ground of the other it creates uneven wear of the electrodes, so those of you who use platinum tip plugs and don't change them for 100K miles or more, would do well to switch the plugs around in the cylinder pair every 16K miles or so. Of course if you use ordinary plugs and change them regularly this is not an issue for you.

Pete
Click to expand...

For a diagram of what Pete is trying to describe see the following link:

Ignition explanation

An except is as follows:

The third type of ignition system is the distributorless ignition. The spark plugs are fired directly from the coils. The spark timing is controlled by an Ignition Control Unit (ICU) and the Engine Control Unit (ECU). The distributorless ignition system may have one coil per cylinder, or one coil for each pair of cylinders.

Some popular systems use one ignition coil per two cylinders. This type of system is often known as the waste spark distribution method. In this system, each cylinder is paired with the cylinder opposite it in the firing order (usually 1-4, 2-3 on 4-cylinder engines or 1-4, 2-5, 3-6 on V6 engines). The ends of each coil secondary leads are attached to spark plugs for the paired opposites. These two plugs are on companion cylinders, cylinders that are at Top Dead Center (TDC) at the same time. But, they are paired opposites, because they are always at opposing ends of the 4 stroke engine cycle. When one is at TDC of the compression stroke, the other is at TDC of the exhaust stroke. The one that is on compression is said to be the event cylinder and one on the exhaust stroke, the waste cylinder. When the coil discharges, both plugs fire at the same time to complete the series circuit.

Since the polarity of the primary and the secondary windings are fixed, one plug always fires in a forward direction and the other in reverse. This is different than a conventional system firing all plugs the same direction each time. Because of the demand for additional energy; the coil design, saturation time and primary current flow are also different. This redesign of the system allows higher energy to be available from the distributorless coils, greater than 40 kilovolts at all rpm ranges.

If this is indeed how the circuit is done on the ST1300 then pulling the one plug wire will disable spark at both cylinders....but on that note I found this
here:...

"An important point to keep in mind with respect to all types of ignition coils is that when the magnetic field collapses, the high-voltage surge has to go someplace. If it can?t go to the spark plug, it will find another path to ground - which may be back through the ignition module, PCM driver circuit or through the insulation inside the coil itself. This can be very damaging to these parts. So never disconnect a plug wire or COP coil while the engine is running. It can be very damaging as well as dangerous to you should you become the path to ground."

So, it may not be a good idea to remove your wires for diagnostic purposes. I would think that a proper overall system design should account for the very real possibility of someone removing a spark plug wire during the lifetime of the bike though...
 
With a "wasted spark ignition", two spark plugs are connected in series with the secondary winding of the ignition coil. One plug is connected to the negative side of the secondary coil winding and the other plug is connected to the positive side of the secondary winding. Thus, when the coil fires, it creates a high voltage spark across the gaps of both plugs at the same time. One plug fires in the traditional polarity of an ignition system (- to +),
while the other plug fires in the reverse polarity (+ to -). Removing one plug wire opens the entire secondary of that particular coil and will stop the firing of both cylinders that are served by that coil.

Barry
 
I'll have to ask the Technician what has been their experience with removing one plug cap or another. They seem (at least at this Dealer) to use that as a trouble shooting method. That's how he found my "damaged" plug cap that shocked him even with a plug cap pliers (?).

Anyway, that's what they said.

Hopefully my parts will be in this week and they can be swapped out but, the weather is supposed to be in the upper 70's later in the week. Don't know if that will be hot enough to get Indigo to act up???

Time2Work
Neil S.
 
09/11/07 Update:
New pulse generator installed (that's the electrical device on the front of the crankcase) and rode 100 miles.

No problems but................................... temps are only in the low to mid 70's. It may not be hot enough to have the REAL culprit raise it's ugly head.

Tomorrow s/b warmer and Thursday. We will see, my fingers and toes are crossed (kinda hard to walk that way or twist the grip).

Later
Neil S.
 
13Sep07 Update:
Between yesterday and this morning I did 225 miles. No issues. Today was 87 deg I did 75 miles on the way home and no issues. :policeST: Do I think it's solved................................................................................................. it is better. It's not hot enough and/ or I haven't ridden long enough to be sure.

:) Time will tell but it is looking better than it has since last spring..

Time4Bed
Neil S.
 
Interesting and very good news (especially if the problem is never seen again!).

Mark
 
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