Weak spark on GM 350 with new coil

[hn2704]

Hi,
I just replaced the ignition coil and rotor, breaker, condenser on my GM350 engine. When I check the spark coming out of the coil, the spark is still weak: purple, short spark. What could be the problem? Also, sometimes, the engine would start up easily and run for 15" and the and could not start at all the next minute. Could it be ignition problem?
Thanks

 

[Reel Poor]

Re: Weak spark on GM 350 with new coil

If your checking the spark from the coil WIRE, it could be a bad wire. Possibly point dwell set wrong, low voltage to the coil, or bad distributor ground.

 

[Bondo]

Re: Weak spark on GM 350 with new coil

And it would help,..... Alot ......
To know Who's 350 your working on,........As well as the Vintage.......
OMC,..??
Merc,..??
Volvo,..??
Crusader,..??

 

[hn2704]

Re: Weak spark on GM 350 with new coil

it was an OMC GM350 engine. I changed the wire, set point gap according to spec 0.018" ( I don't have a dwell meter). No improvement. Then I found the purple wire that connected the coil with the starter was loose. I tighten it and the engine started every time. I guess that when I cranke the engine to check for spark, the voltage was not strong enough to get a good spark and caused a hard start. Am I right?

 

[Reel Poor]

Re: Weak spark on GM 350 with new coil

It is possible. A bad connection can/will cause low voltage symptoms.