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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: KBikeRule on August 21, 2016, 04:02:04 AM

Title: Engine Miss - No Voltage to ONE injector
Post by: KBikeRule on August 21, 2016, 04:02:04 AM
Greetings...

I recently completed some maintenance on my '92 K100RS... had a headlight issue... disassembled the starter and cleaned it... soldered on a new headlight terminal and that took care of the headlight issue (disassembled the started just because of the volume of info on carbon build-up)... got the bike back together and now I have a miss in Cycinder 1.

Installed new plugs a couple of weeks ago... new plug wires too.  Plug #1 appears to be firing (some carbon - not like the other three plugs that are firing with fuel).

Fuel injectors were cleaned a year ago and they were really fine to start with.

Checked the voltage at the #1 fuel injector... no voltage on either terminal.

Re-seated the connectors to the FI Unit... didn't help.

Most trouble shooting charts don't really apply to one cylinder-missfire issues.

I'll work on it again tomorrow... but... if it's a break in the leads to the fuel #1 fuel injector... how do I rewire it? 
Title: Re: Engine Miss - No Voltage to ONE injector
Post by: kennybobby on August 21, 2016, 09:52:16 AM
You will need to trace the harness to find the junction point of the 4 injectors into 1 and inspect the solder joint of the green/red wires that supply +12 vdc to the injectors, then check the continuity from injector 1 to that joint to determine if the wire is broken or the solder joint is cracked. 

Probably need to check for the yellow/gray control wire 4-into-1 joint also.  If the injector#1 harness got pinched it might break both wires.
Title: Re: Engine Miss - No Voltage to ONE injector
Post by: Inge K. on August 21, 2016, 10:02:07 AM
First, check the connector for the injector......repair sets you find on the net.