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You can trim the coil wire that goes into the boot to get a better connection. Pull the boot off and test it on the plug to see if it has a tight connection.


Arcticfrost
 

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Discussion Starter #22
Thank you for the thoughts. The plug cap is tight. I trimmed 1/4" off coil wire and rethreaded just to see. No difference. I heard the connector "snap" on when I connected to plug. The wire is tight to the coil as well. I retested the coil. 4.8 ohms terminal to terminal as per spec. 20.95 kohms from cable (sparkplug end with sparkplug boot removed) to the terminal. This continues to be on the high side of spec which is 12 to 19k.

I discovered a crack in rubber plug boot. I will replace it. There is no metal in proximity to this crack so I don't believe there is any shorting happening here, but I mention it in case I'm naïve. The quad still misses when I'm running it with the inline tester and this "cracked" boot is in a completely different position during those tests.

I added some Lucas injector cleaner to the fuel this morning. I figured I would give that a try as someone in this forum had similar symptoms as mine and that cured his. It hasn't helped mine (yet)..

A friend suggested that when it is missing bad and consecutively, I should spray some gas into the intake to see if the RPM's recover. If it's a fuel issue he thought the RPM's should pick up. I removed the air breather and shot some fuel into the intake with as Syringe as I was driving and it was missing. There was no improvement in RPM. It seemed to make no difference at all. Even when it was idling with no miss, the added fuel didn't seem to do much. That caused me to go full circle and question the spark again. I installed the spark tester (light) and drove around again. Earlier I concluded that the spark was continuous even when it was missing. I'm no longer so certain that I would see a miss. I did the latest test at dusk. As it misses and the RPM drops due to the missing (throttle constant), the spark is slowing as well. I don't know whether the reduced RPM is caused by slowing spark, or if the slowing spark is caused by reduced RPM. It feels like a chicken and egg. I'm really not sure if this spark tester is going to be helpful?

It is close to freezing here. I feel like there is a temperature component to the missing i.e. the missing gets worse as the engine warms up.
 

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Did you try a new fuel pump?


Arcticfrost
 

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Discussion Starter #24
Thank you. I haven't tried a new fuel pump. I teed in a pressure gauge so I could watch what the fuel pressure was doing while driving around. The fuel pressure is steady at 44 psi even when the machine is missing. In your experience with faulty fuel pumps, was it soley a problem in that they didn't generate enough pressure? Or were they somehow messing with other things (perhaps electrical signals)?

I forgot to mention that I've also monitored the battery voltage while driving. It is solid at 14.6 volts when driving around (even when the machine is missing).

There are two wires that attach to the coil. One of them is rock solid (I think 14.9 volts) and the other one moves around quite a bit. Typically in the 13.8 to 14 Volts range. I don't know if that is significant.
 

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Carefully check all the pins in the connector that goes to your ECU.
 

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Discussion Starter #26
I had time to look at the quad today, but do you think I could get it to miss? Not a single miss in half hour of driving. So I was left wondering what had changed.

The first big change is the weather. It's below freezing. I have felt in the past there was a temperature component to the misfire and this is cooler than I've ran the quad since the problem began.

The other change I did was I pulled an reinstalled the diodes in the fuse box in order to test them. They were both installed correctly when I opened the fuse cover, and they are both installed correctly now. Some Arcticchat threads suggest that the resistance should read open on a diode when the leads are hooked up one way, and the resistance should be low when the leads are reversed. In my case, it read open in one direction and 7 or 8 megaohms in the other direction. That's definitely not low resistance! None the less, I think these diodes are fine. I hooked then in a circuit with a 1.5 volt battery and the voltage drop across the diode with the leads hooked one way was 1.56 volts (full battery voltage implying no current through diode) and when the leads were hooked the other way, the current did flow through the diode and I saw 0.5 volt drop across the diode. I think it's supposed to be 0.7 volts for this type of diode. I figure that was close enough as both diodes are reading similar and there is clearly flow of current in one direction and none in the other. That's what a diode is supposed to do, and mine are acting correctly.

One other thing I did before the test drive was check a couple connections again at the throttle body. I was very intrigued by the following thread because his description of the problem was 95% similar to mine. I too had noted the miss is uncommon in reverse gear, but I did get it to miss on one occasion in reverse (one random miss, but not sequential misses), so I did not mention this to anyone. 2009 700h1 runs great in reverse His problem was a broken wire near the connector to the injector and he shows a picture. I was feeling around for this wire before the test drive today and I wondered if I "moved" something in a favorable manor that had caused the quad to run without missing. It's a wire that is really hard to get at, so I couldn't really see if it was good or not.

I had time, so I decided to take off the rubber boot that connects the airbox to the throttle body to get a better look. This allowed me to gain access to remove the wire connector from the fuel injector. Unlike the referenced thread, my wires looked good at the connector. I decided to check the resistance of the blue wire that runs between the fuel injector and pin 16 on the ECU to see what happened when I moved the wire around. The attached pictures shows how I measured this (needle into pin 16, and wire into the fuel injector connector). Resistance was 0.3 ohms, which is good. When I pinched the connector wiring between my two fingers, the circuit went open. Thus, I suspect a broken wire (I don't see any chaffing in this area). I'm 95% certain the problem is a broken wire. I haven't quite figured out yet how I intend to repair. There isn't a lot of room to work. Rather than trying to locate the problem and repair it in a confined area, it might be simpler to just run a new wire from the injector to the ECU. I had enough for today, and I figured I would post this information and see if anyone had any thoughts on the best way to repair.

Thank you
 

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Its been posted already, but first thing to check is the boot between the throttle body, and intake, if it has 2 clamps, it is prob cracked and leaking when the engine torques over under load. Next are the wires going to the throttle body, they are known to be a little too short, causing a break, or terminal to be pulled out (I've found wires to be broken inside the insulation, with no visible clue)
 

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Salad,

do not fear taking the plastic off to get to the injector and wires more easily. It is about an hours work is all. It is pretty painless, just lots of screws and I needed help twisting the plastic around the handle bars. I feared I would crack the plastic. Once you get it off, going back on was easier. And you do not need the plastic to drive it - so you can test any fixes before putting the plastic back on.

I chased my problem down thinking an intermittent short, but it ended up being the fuel regulator.

You seem like you are narrowing it down.

Skippy!
 

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Discussion Starter #29
I've changed the subject to indicate this is resolved. I peeled back the insulation on the blue wire and found a break about 1" from the connector. I soldered in some new wire, liquid taped it, electrical taped it, put it back together and took it for a drive. There was no missing. Tools are put away, garage swept, quad put away. Thank you everyone for your thoughts/ideas. They helped a lot!
 

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Great to hear. Good trouble shooting skills
 

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Discussion Starter #32
That's correct.....blue wire was broke within the insulation about 1" from the connector. I posted a picture earlier showing how I tested for resistance between the connector and ECU. I think I got a bit lucky in that as soon as I moved the wire the resistance tested open. A friend of mine suggested that I should "pull" gently on the wire. I think that would be a surer way to find a break within the insulation.
 

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you can get an injector pigtail, or just a pin to help with the fix.
while you are there, make sure to check the wires going to the MAP and TPS have enough slack to move when the engine rocks under load.
 
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