Coil fires in the RUN position

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TheBestEspresso
Posts: 11
Joined: Wed Jan 30, 2008 6:05 pm
Car: 1989 240sx coupe
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CAR: Mostly stock '89 coupe. I say mostly because for sake of a list, anything that could be wrong with it is factory stock.I know I do not post regularly here, but damn I need some help. This car has just been nothing but trouble recently. I need a clutch & it's almost here but that isn't my main concern now. Here is the deal. The throw out bearing is/was pretty seized. Every time I push in the clutch it would just about stall & it was making the typical bearing squeal....ANYWAY. I parked the car a few weeks ago & it has been sitting dormant. A few days ago I go to start it so I can wash it & turn it around for when the tow truck gets here. It started fine like it always has. Push in the clutch SQUEAL(of course) & pull it forward about 20 ft. Shut it off, throw a bit of water on it & just quickly wipe it down with a towel(nothing in the engine bay just exterior). Car was shut off for about 5 minutes. Go to start it back up..NOTHING. Just cranks over. So I had to push it backwards(with a welded diff..oh what joy) into my parking spot. Start the diagnosis..let the fun & head scratching begin 1st...check the ECU. Key in the RUN position. I notice the GREEN light is flickering...humm..WTF? Go to put it in diag mode...NOTHING..still got a flickering green light. I sit up going WTF. Then I listen..."whats that" cli,click,click,click,cki,click... EGI(fuel pump relay) going crazy. Check fuel pump manually..works fine. Turn the key to OFF Back on to run, same ol click,click & flickering green light. I listen more..TAP TAP TAP...WTF is that now? THE DAMN COIL WIRE IS FIRING. But, I notice the coil wire is firing at the same rate that the green light is flickering. So I take off the wire to the cap & rest it against the shock mount to observe the spark..sure enough. The brighter the green light is the brighter the spark(yes the spark will travel through the cap & plug wire) Mind you, when I try to start it.. I have a push button start & had it for month with no troubles. It cranks the car just fine. I go to start the car..the spark STOPS, it doesnt not just fire up, the spark & current to the coil STOPS. So now I am really at a loss. I am sure the ECU is gone. I disconnected power to the coil, resistor, MAF, coolant & fuel pump, now I just get a flickering green light. I even took out ALL the fuses & links, still get a flickering.

I can post pics & video if I need to.

This just has me scratching my head. NO I cannot just swap parts with a friend either. I have the only(that me, or any of my friends here) ka24e 240sx.

Thanks for ANY help
Modified by TheBestEspresso at 4:56 PM 7/28/2008


TheBestEspresso
Posts: 11
Joined: Wed Jan 30, 2008 6:05 pm
Car: 1989 240sx coupe
Contact:

Post

OK, doing more troubleshooting. I pinned the entire ECU & it is fine.

I cut the ignition switch wires off, so I can isolate the different circuits(switch was bad anyways). One thing I found out. The circuit to power up the coil(red/black wire) is where the problem lies. I had the white & Rd/BLK wires twisted together & with just power going to the coil it get to hot to touch. You can feel the heat coming off it.

I was looking in the schematic & it says that there is a "condenser" inline with the coil & power transistor, but i'll be darned if I can find it.

I know the problem is obviously in the ignition circuit. All injectors are getting power, fuel pump gets power & pumps fuel, MAF is fine. I checked the CAS w/ DVOM & from what I read it checked out OK. I have unplugged EVERY relay in the fuse box, pulled one fuse at a time. I still get the flickering green on the ECU.

I am truely at a loss. ANYONE have any ideas? I got the entire harness just about pulled out & the dash is out. So I can check everything. I do not mind putting toggle switches on everything if I have to. This is not a car that needs to pass a real inspection. In a few months we are getting a new car & I am gutting this car. BUT, right now I NEED it to run so I can get the clutch put in & the car inspected. As it is due by the end of AUG.


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