weak spark
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Cross-Country
Joined: Jun 2012
Posts: 85
Likes: 0
weak spark
hey guys im trying to get a truck started thats set for 20 plus years,,i changed coil,plugs.wires cap rotor cleaned the pick up and everything the coil looks to be sparking good but it wont hit off of starting fluid.....i can take a plug out put it in a wire crank it and it wont jump from the plug to metal and fires light orange ....could the icm cause this.....its the blue colored one.....any help would be appreciated
Cargo Master
Joined: Oct 2016
Posts: 2,738
Likes: 217
From: Northern VA
Check grounds and connections for tightness and cleanliness.
Use a strong battery and clean/ new spark plugs.
Finally, your timing may be off or you have vacuum leaks.
Do you have compression?
Use a strong battery and clean/ new spark plugs.
Finally, your timing may be off or you have vacuum leaks.
Do you have compression?
Laughing Gas
Joined: Nov 2013
Posts: 1,207
Likes: 60
From: S.E. Louisiana;so far USA
A lot of things, including the ICM, could cause a weak spark. I realize that you're utilizing the starting fluid, but it might also be good to assure that the engine is getting some fresh fuel. After sitting for 20 years sometime fuel problems can be contributory to hard starting.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
You've isolated the problem to somewhere in the distributor. The cap, rotor, and wires, and plugs are new right? Assuming these are good, then it doesn't leave much else.
There is a ground wire inside the distributor housing on the breaker plate. Also the distributor itself, grounds to the block through the housing. Has the engine block been repainted by chance, something like that? Or for grins, attach one end of a jumper cable to the distributor housing, and the other end to battery negative terminal and see if the spark at the plug improves.
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