Roger Hodges X won't fire

[wytfut]

Here's another new one to me...

Roger Hodge has been trying to get his  x running since before the X rally.  He brought down to my place last nite..... and worked on it today....

With everything I ran thru and checked.... we came up with this:
There isn't enough electrical coming thru the leads to the spark coils....    its reading between 2-.199 volts. Swapped coils and checked leads on my X.... and those leads read 12 volts....

No fault codes are showing on the superxtune.....  no engine speed sensor, etc. ..

thinking that there was a possible glitch in ECU I reflashed the tune to it...  no change

I'm guessing at this point without more direction that the ECU has an issue....

anyone have any ideas where to look next just to point me in another direction, or verify my thoughts?

thanx guys!!
Bruce

[2CoolWheels]

Bruce,
   According to the wiring diagram, your coils are fed 12 volts from the 15 amp EFI fuse. There should be 12 volts present to one of the wires at all times with the ignition turned on. The ECM will provide the negative signal to the coil to fire it.
   I would double check the fuses if you haven't already. If your fuse is good, and you still don't have power to the coil (wire #1, Orange/White), then there may be a broken splice where the fuse power wire (White/Black) is spliced to the coil power feed (Orange/White).
    However, I couldn't begin to tell you where to look for such a splice, somewhere in the wire harness.

[wytfut]

thanx Mike...
The EFI fuse is fine, although it had been blown at Rogers house last week. But currently we're getting good fuel pressure.
And yeah we got a good 12 volts on the lead to the spark/coil on my bike,..... even before cranking.
I'm starting to be tempted to check out some of the larger connectors on the way to the ECU and relays...  but its really not looking like that is the issue, as many systems run thru these same connections, and we don't have any problems with anything but the ignition at this point.
Don't put that thinking cap yet....

[2CoolWheels]

Bruce,
   There are several things fed by that EFI fuse besides the coil. See if you are getting 12 volts to Purge valve, road speed sensor or pin H4 of the ECM. If you have power to any of those points, then the splice is probably ok. Check plug P41. Power from the ECM feed goes through that plug before it reaches the coils.
   It does concern me that the ECM fuse was blown....might be a damaged wire. But, you know that story well....
   Mike

[wytfut]

Well Mike you know me.... pretty much a simpleton that won't quit....
Got a call back from Jamie a bit ago...
Jeff and I both didn't realize that the common wire thru out the system is a positive.... we both thought it was a common ground.
With that knowledge, it changes everything... and gives us a whole new point of attack....
We'll be tackling the wiring harness and each of the components that are on that common o/w... for voltage....

thanx Mike... knew you'd keep me in the loop....

Bruce

[Jumper]

Hey Bruce... Any update on Roger's X?

Jumper

[wytfut]

Yes sir..... and I was going to post but forgot.... Thanx for the reminder...

Roger hauled his X down to me (close to 200 miles) to figure out why his G/O won't start.
Buddy Jeff and I determined a lack of voltage to the spark coils as previously stated. At that point we didn't know what the voltage was supposed to be, plus we were under the impression that the O/W was a common ground. .... whereas in reality the O/W is a common positive.

Called Mr. Jumper and Jamie Jones.... to find out both after Roger left to head home and he left his X with me....

Uh.... should state right here for future reference of everyone that reads this..... its a constant 12 volts everywhere the O/W goes....  the other wire at each lead is the control wire from the ECU.

Jeff and I last Thursday set that evening up as the nite. We're both retired telephone men, so this was a challenge that we were up to with no regrets. Within 20 minutes of isolating and testing.... we found the culprit. Connector P41 wasn't quite "snapped" together. It looked like it was, but it wasn't.   

With the initial attack (of a couple of hours into it) when Roger was present, and not having the correct info....  I have to admit, I was a bit befuddled as a point of attack. Especially not knowing about the O/W.  I could have had Roger load up his X running just fine.....

But such as it is.... Its now running fine and Roger will be picking it up Friday p.m.

This issue to be frank was humbling to me.... and I'm sure to Roger too. CHECK THOSE CONNECTORS FIRST!!

Bruce

[deadwoodsp]

Glad to hear you got it going.  Good job Bruce.

Dennis

[Jumper]

THREE CHEERS FOR BRUCE!!! It's the staring at you in front of your face easy fixxes that get you every time! Ahhh... The joys of X!
Jumper

[2CoolWheels]

Good job Bruce. Now Roger won't have a reason to miss next years X-rally!