Hot Coil / No Spark EFI
05-07-2010 | 06:42 AM
#1
Thread Starter
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Joined: Oct 2003
Posts: 3,739
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From: Ohio.
Hot Coil / No Spark EFI
We got no spark and coil gets hot.. On an EFI engine..Replaced coil... Same thing is happening. Switch modual on distributer.. not the problem.. Where to look next??? Thanks Scott
05-07-2010 | 07:15 AM
#2
Charter Member
Joined: Jan 2001
Posts: 7,663
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From: Edgerock Baby!!
Can you swap ECUs? The dist sends a signal to the ecu and the ecu sends it back to the coil, it may be getting lost in there.
05-07-2010 | 07:39 AM
#3
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Joined: Aug 2001
Posts: 4,008
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From: Aurora Ontario
Good point Ted. The output transistor that drives the coil can short to ground. An easy test is to use a low amps probe on a scope or a meter and clamp the probe around the coil negative wire as close as possible to the ECU. If the probe shows current flow with the key on / engine off, the ECU is the problem. If it does not show, start moving the probe towards the coil. If a reading shows up, look for a shorted wire from the coil to engine ground.
You can also just unplug the ecu, turn the key on and check for current flow. If the ecu is at fault, there will be none. If the wiring harness is at fault, the coil will still get hot.
You can also just unplug the ecu, turn the key on and check for current flow. If the ecu is at fault, there will be none. If the wiring harness is at fault, the coil will still get hot.
