1997 0x66 SX250TURV only running on 5 cylinders coil ruled out..

[scjmc]

So I figured out that my engine is only running on 5 cylinders. My cylinder #3 is not firing. No spark... I conducted tests above 2K RPM (I know that it runs on 4 or 5 cylinders at lower RPMs but I am not sure which ones). I swapped coils between #3 and #5 and the problem does not follow the coil. I checked the wiring harness between the coil and the CDI unit. I also checked the OHM specs on the pulser coil 353-360 on all 6 coils. I dont know what to do next. Is there a better way to test the pulser coil? Is there any thing else besides the pulser coil and the CDI that could cause a no spark condition in only 1 cylinder? Thanks....

 

[scjmc]

Re: 1997 0x66 SX250TURV only running on 5 cylinders coil ruled out..

Alright then. I am taking this to the professionals to see what they find...

 

[jeffersondodson561]

Re: 1997 0x66 SX250TURV only running on 5 cylinders coil ruled out..

Have you checked the coil resistance cap? With your DVA check primary voltage at the coil.

 

[scjmc]

Re: 1997 0x66 SX250TURV only running on 5 cylinders coil ruled out..

I checked the resistance of the ignition coils, and also the pulse coils. I am not sure of what you mean by "coil resistance cap" The pulse coils were all 353-359 OHMS if I remember correctly. It is at the shop now they are looking at it tomorow. I dont get any detectable voltage out of the computer to the #3 coil at any RPM.

 

[jeffersondodson561]

Re: 1997 0x66 SX250TURV only running on 5 cylinders coil ruled out..

Those orange spark plug caps are resistors to reduce RFI noise to the ECM. Unscrew the orange caps and test seperately should be 4-6Kohms.

 

[jeffersondodson561]

Re: 1997 0x66 SX250TURV only running on 5 cylinders coil ruled out..

The pulse coils were all 353-359 OHMS if I remember correctly. It is at the shop now they are looking at it tomorow.

Invest in a DVA, it allows you see what the CDI needs to see to operate properly. Resistance sucks!

 

[scjmc]

Re: 1997 0x66 SX250TURV only running on 5 cylinders coil ruled out..

Thanks for the replies. Sorry it has been a while since I posted. I got the boat back from the mechanics and took it for a ride~perfect. I got food poisioning real bad right after I got the boat back and am just now getting back into my routine. The issue was in the wiring harness itself. I am not sure where, but they had to replace a section of wire. My visual checks were not sufficient. They also found 1 butterfly valve not opening or closing fully due to a loose adjustment screw. Like many others I tried to fix it myself and failed. I will do better next time. Thanks again for the input.

 

[scjmc]

Re: 1997 0x66 SX250TURV only running on 5 cylinders coil ruled out..

Those orange spark plug caps are resistors to reduce RFI noise to the ECM. Unscrew the orange caps and test seperately should be 4-6Kohms.

Yeah I need to test those again. I havent in a couple of years, and I was getting shocked through one of them when I was troubleshooting.