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Stranded with no spark - LH 2.4

Tfrasca

Active member
Joined
Apr 20, 2015
Location
Ben Lomond, CA
Just drove my 142 (with b23 and LH 2.4) for the first time in a few weeks, and it had a dead battery. Jumped it and it seemed to be running fine. I was at a light and as soon as I flipped the turn signal on, it died and wouldn't start.

I got another jump and it idled for a few minutes with good voltage, then died all of a sudden. Now it just cranks and doesn't spark. Fuel pumps are running, pressure is good. No spark at coil.

I had to leave the car, but I'm going to go back to diagnose. I didn't even have a chance to pull codes. I'll bring a voltmeter and a green book, but it seems to me that something shorted. Any thoughts?

Things that come to mind are CPS and maybe power stage, but I'm shooting in the dark at this point.
 
I like to start at the power stage. It's a good mid point area of the system. If the trigger signal isn't going to it. Then you work back from there. If the trigger signal is going to it but no output to switch the coil it's probably the powerstage or something in that part of the system. Make sure the coil is getting voltage on the positive terminal as well.
 
I like to start at the power stage. It's a good mid point area of the system. If the trigger signal isn't going to it. Then you work back from there. If the trigger signal is going to it but no output to switch the coil it's probably the powerstage or something in that part of the system. Make sure the coil is getting voltage on the positive terminal as well.

Ok, I'll start there. It looks like pin 1 sends voltage to the coil, 2 and 3 are grounds, 4 receives battery voltage, and 5 receives signal from CPS. Is that right? Can the CPS signal be tested with an LED test light?
 
Well, this was weird. Swapped another EZK in and it fired up and drove home.

I pulled the other one apart and didn’t see any obvious shorts or physical failures in the board.
 
That's strange as hell, those EZK's are usually pretty solid. Is that the EZK from Ryan, or your original one?

I put the chip from Ryan in the gold box I had, and that's what was acting up. I swapped in the un-chippable black EZK I had and it worked. Really strange. There was no major "event" that would cause a short or a failure. Just a slowly draining battery.
 
Glad you got it figured out. They don't fail much but it does happen. Do you have a stereo with memory? That may be the battery drain.

I have a stereo, but I had the battery disconnected for the last few weeks while the transmission was out. It's an Odyssey PC925, so it doesn't have a huge capacity, and I think it's just been run down too many times. It's always dead after being disconnected for a while. Usually I can jump it and spend twenty minutes on the freeway and it charges up.
 
I was looking at a schematic for the power stage for the OP and came across a peculiar symbol, and has piqued my interest to what it is.

Does anyone know what the purpose is for the grey wire connecting to pin #3. It appears in the diagram below it goes to a dashed circle around the other grey wire (pin #5)

Is it connected to the other grey wire or is it a guard? If it's a guard, are the two grey wires just twisted around each other and connected at another point?




https://s19.postimg.cc/k2oapcqub/Powerstage.png
 
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Does anyone know what the purpose is for the grey wire connecting to pin #3. It appears in the diagram below it goes to a dashed circle around the other grey wire (pin #5)

Is it connected to the other grey wire or is it a guard? If it's a guard, are the two grey wires just twisted around each other and connected at another point?




https://s19.postimg.cc/k2oapcqub/Powerstage.png

Pin 3 is the shielding for pin 5, which is the CPS signal. Pin 3 is just a wire that wraps around the signal wire from the CPS signal wire, then grounds at the power stage. At least that's what I gathered from looking at it just now.
 
Pin 3 is the shielding for pin 5, which is the CPS signal. Pin 3 is just a wire that wraps around the signal wire from the CPS signal wire, then grounds at the power stage. At least that's what I gathered from looking at it just now.




Thanks, I couldn't remember for the life of me!
 
Hmm, I wonder if the chip didn't seat fully perhaps? Strange either way though. At least you got it back home so you can diagnose a little more.

The chip looks like it's fully seated. Now that it runs, I need to sort out the drive shaft stuff, so diagnosing the EZK will happen after the rally in a couple weeks.
 
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