2004 vz260tlrc hpdi flywheel

[Thehunter]

I'm guessing the coils will show same as ecu since coils are downstream and ecu says no spark on YDIS. I checked YDIS signal by unplugging a coIL that said firing while running and YDIS continued to say firing that's why I think it has to be upstream of ECU

[boscoe99]

I'm guessing the coils will show same as ecu since coils are downstream and ecu says no spark on YDIS. I checked YDIS signal by unplugging a coIL that said firing while running and YDIS continued to say firing that's why I think it has to be upstream of ECU

The ECU voltage is not necessarily the same voltage that is seen by the coils. The coils get their voltage from a separate power source. A different wire that is. The only connection to the coils by the ECU is when the ECU applies or removes the ground lead to cause the coil to fire the spark plug.

The only thing that I see common to the three coils on one side of the motor is their voltage source. If that voltage is intermittent for any reason then all three of the plugs could be made to not fire.

That is what you are seeing correct? Three coils on one side that fire intermittently?

[Thehunter]

Mostly correct...YDIS shows intermittently fire to these 3 cylinders and I have confirmed. I'll try to explain intermittently so it will fire #1 and not 3 or 5 then a second layer fire 3 but not 1 or 5 then fire 5 then maybe 1 and 5 together then 3 only then 3 and 5 and so on and it move around them so fast it's hard to keep track of. It like Christmas tree light with computer saying fire and no fire. I hope this explains it....what should I check?

[Thehunter]

The only adapter I have for YDIS is to the ECU. So this is what the ECU is telling YDIS.

[Thehunter]

Traced all the red/yellow coil wires back to a plug that plugs into fuse box. All the black/various color wires go to ECU. Do the coils have voltag ed static or only when eine is running?

[boscoe99]

The coils have voltage available to them when the key is in the on position.

Almost all of the red/yellow wires function in this manner.

Red is battery voltage. Yellow is key on power. Red/yellow is key on power usually via a relay/fuse/etc..

[Thehunter]

Thanks I'll check for power however I still think it's before the ECU since the ECU says no firing and when it was running I unplugged a good firing coil and ecu still said firing. Thoughts?

[Thehunter]

I also noticed that the spark was weak on 1,3,5 when it was sparking. Not even close to as strong as 2,4,6. Check pulsar wires again all ohm at 350...

[99yam40]

why not measure the voltage to the coils if you think the output is weak

[Thehunter]

Should the voltage be 12v at the coils

[Thehunter]

Should the voltage be 12v at the coils

[Thehunter]

I checked powe at coils all r getting 12.8 v

[Thehunter]

Any other ideas?

[rodbolt17]

my idea
PROPERLY test the dang thing.

use the service manual and a peak reading meter.
test the ignition coil primary output voltage.

IF YDS says that cyl is not fireing that is because the ECU shut it off.
the ECU does NOT monitor if the circuit actually works.

monitor the shift cut,on or off and the shift position on or off, while it is running.