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97 vfr750 spark mystery.


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1 hour ago, Dougwfresh said:

That’s is what’s going on. It’s just hard for to believe two box’s are bad in the exact same way.

 

 

i agree so it must be something else but what ?????

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15 hours ago, Dougwfresh said:

That’s is what’s going on. It’s just hard for to believe two box’s are bad in the exact same way.

 

Well, based on everything you said you've checked and replaced. I can only make a guess at one or more of the Ignition reluctors/magnets on the starter outer might be damaged, potentially upsetting the ignition pulse sequence to the ICM, not triggering #1.

 

There appears from what you've done nothing left that hasn't been checked.

 

And just because a low capacity battery has caused strange issues with any bike! Are you sure your battery and its connections are good and solid?

 

Perhaps there may be a VFRD member near you with the same bike that might allow you to use his bike to at least confim the status of both your ICM's. Let's hope someone chimes in.

 

Good luck, keep us posted with whatever you find.

 

Post edit - Or you had a shorted #1 coil that was replaced after fitting the second ICM. Blowing the output of both ICMs?

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I found some articles stating wiring-harness short can blow individual coil-driver output transistors. That might be why 2nd ICM is also now dead on #1. So DON'T try known-good ICM from another bike on yours, might blow it too. You can try yours on their bike to confirm #1 channel doesn't have spark.

 

TEST#1: ICM disconnected, key OFF, measure resistance of each coil-trigger wire to chassis ground.

 

TEST#2: ICM disconnected, key ON, measure voltage at each coil-output terminal at ICM connector

 

TEST#3: ICM connected, key ON, measure voltage at each coil-output terminal at ICM connector (backprobe connector)

 

 

Where are you located? Or more specifically you have NA model? Some questions about it:

 

- does it crank with kill-switch off?

 

- does interloc safety switches work? Does kickstand/neutral switch disable bike properly?

 

- does bike have manual fuel-pump switch? Lets you run pump by hand to prime?

 

Some of these non-standard behaviors can point to short.

 

 

Also when  testing pulse-generators, clearance can be set with business-card. Feeler-gauges get stuck by magnetism and you can't get good feel for clearance. I'm in S.F. Bay Area, if you're near. Scoping pulse output waveform is my 1st test, most upstream component and ignition circuit starts there.

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20 hours ago, Dougwfresh said:

...number one has the blue with black with the black and white(12v)and number three has red and blue with black and white.(12v) If I take the red and blue and switch it over to coil number one with its black and white cable. I will get spark on coil one and if I hook the black and blue and black to coil number three then I get spark on number three. so it has something to do with the black and blue wire. But it  has continuity between the icu and the coil.

Am I reading this correctly?

 

1. plug R/Bu wire into #1 coil = spark #1

2. plug Bl/Bu wire into #3 coil = spark #3

 

If you get spark on both coils, this is easy! Just swap hi-ten spark-plug wires at coils to swap cylinders and you're done!

 

 btw, if coils have labels for #1 & #3, peel those off and swap them also.

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23 hours ago, Dougwfresh said:

Still no spark # 1. I moved around coils, switched wires from coils 3 to 1. Then I got spark on number 1 but not 3. What ever spark plug I hook up to the blue/black wires no spark

Danno, its a bit confusing, he states here in an earlier posting he never gets a spark from channel 1 wiring! 

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Yeah, I'm not sure what to believe at this point. There was A LOT of parts swapping, so I don't know which symptoms goes with which combination of parts.

 

Might be case of corroded connectors and/or broken wiring? Moving it around may have reconnected break in some cases?

 

That's why I have him test for voltage and grounds with wiring in place. Test signals on wires, but don't change wiring itself.

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Danno, I live is South Lake Tahoe. All my interlocks work expect my side stand. Bypassed it. The bike will not crank with the switch off. I don’t think it had Manuel hand pump.The tests you want me to do. Explain please, I just want to do it correctly.

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17 minutes ago, Dougwfresh said:

Danno, I live is South Lake Tahoe. All my interlocks work expect my side stand. Bypassed it. The bike will not crank with the switch off. I don’t think it had Manuel hand pump.The tests you want me to do. Explain please, I just want to do it correctly.

Danno touched on an interesting scenario - a short on channel 1 wiring.

 

At what stage did you fit a new coil to cylinder #1. ? Was this AFTER fitting the second ICM or before? Because a shorted ignition coil would definetly take out the output stage of that channel of the ICM.

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How about you grab your ohm meter and try a test on the ICM outputs. Comparing the bad channel to a good channel.

 

With ignition Off. Take say #3 Red/Blue wire off the coil and measure its resistance to ground. So red meter lead to the Red/Blue wire, black meter lead to a good ground, negative terminal of the battery. Vary your ohms range and see if you get a reading, now compare this with #1 Blue/Black. Are you getting the same results for the two channels? Any major difference in readings would point to either a wire short OR a faulty output at the ICM.

The importance here is both channels should read the same wether you measure open circuit or anything in between.

 

IMG_0974.PNG

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So did the test to said. Ignition off and remove the red/blue wire from coil because that’s coil number #3 wire. red probe in that wire and black probe to ground and it says OL. On the 200 setting and 2k setting. Same for blue/black and the other two coils. OL

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On 1/2/2021 at 9:17 AM, Dougwfresh said:

So did the test to said. Ignition off and remove the red/blue wire from coil because that’s coil number #3 wire. red probe in that wire and black probe to ground and it says OL. On the 200 setting and 2k setting. Same for blue/black and the other two coils. OL

Ok. So, inconclusive results but worth a try.

Are you going to inspect the Starter Clutch Outer as previously suggested?

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You got me thinking about the coil short frying the number one channel. So when I got the bike together. Tired to start, no spark. Put on aftermarket coils still no start. Then used icm, no fire. used harness, no fire. learned a little how to use multimeter. check all coils new and stock. Stock had why better readings primary and secondary’s . Put those back on. There is a chance stupidly did something when hooking up and swapping things around with hooking everything  up and battery, fried the icm. Idk. I am sure now the wiring is good and true. I’ve checked/tested it all, stater too. There’s not many tests left to do other then when my noid light comes. So I going to move to taking the side cover off and start checking clutch outer and pulse gens.

 

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pulsers can be checked at the external plug, no need to remove cover, and since you get some sparks, there's little chance anything is wrong inside cover.  dija chack pulse coil resistances ?

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7 minutes ago, squirrelman said:

pulsers can be checked at the external plug, no need to remove cover, and since you get some sparks, there's little chance anything is wrong inside cover.  dija chack pulse coil resistances ?

Agree with you, and the resistances have been checked. My concern is for the reluctors or magnets on the starter outer. Just wondering if there's a damaged or missing one that could screw with the pulses for the ICM.

Do you have any thoughts or experience with the starter outer issues?

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2 minutes ago, Grum said:

Agree with you, and the resistances have been checked. My concern is for the reluctors or magnets on the starter outer. Just wondering if there's a damaged or missing one that could screw with the pulses for the ICM.

Do you have any thoughts or experience with the starter outer issues?

 i've had to replace one starter clutch case due to cracking. i suppose a small piece of steel could have broken off somewhere and stuck to a pulser coil.............but then it wouldn't fire on two cylinders i think.

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When I got the bike the pulse gens were hanging on the out side of the case cover. Previous owner Started to do the oil cooler delete and ran out of time due to family and kids etc. sold me the bike I finished oil cooler delete. Reinstalled the pulse  generators and the bar they bolt too. all the wires everything seem to be good and work condition. reinstalled clutch outer torqued everthing to spec. Installed new clutch. Installed cover then all this. The gens test good tho at 302ohms 2k

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really ?? ??? i can't understand why any rider might want to remove the oil cooler, especially if riding in warm or hot weather. no good reason for it as far as i can see, and no need to get into the cover or remove pulser coils for a cooler delete.   have you tested the ht lead from coil to plug for proper resistance ??  occasionally a sparkplug resistance cap can go bad. should be about 25k ohms.

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