What Can Cause A Weak Spark

I installed a rebuilt dizzy in my 1990 dx. But it's almost impossible to start the car. It takes a lot of playing with the dizzy for the car to even start and when it does it doesn't run well. The spark is extremely weak so we took the dizzy out and installed it in another car. It started right up. Strong spark there.
What could be the problem? my car is not starting without loosening the dizzy and moving it around. One mechanic told me to check the ECU. I did with the whole jumper thing, but the CEL does not blink at all. what could be the cause of the weak spark.

It seems as if it sparks sometimes and doesn't spark at other times.
Could it be the timing and if so how do I adjust the initial timing.
I've had this problem for over a month now and the problem is that there are no good mechanics in my area so that's why I want to try to fix it myself.

please help

have you checked your plug wires?

check your plugs too while your in there......


gunnmen01

the plugs are fine and the wires are fine. bought a new set just last week. It sparks but really weak.

maybe a relay? Did you check all your grounds?

Coil, igniter, battery, rotor, cap, wires
Main relay wouldn't be a problem with spark because it controls fuel.
Timing - http://www.binghamtonlife.com/manual/2gsm/images/91-23-58.jpg
Full manual - http://www.binghamtonlife.com/manual/2gsm/default.htm

When my ignition coil cracked, my plugs were still sparking but weak as hell. it was cracked inside an arking all over. but you said it got strong spark installed in another vehicle so could something else. cant hurt to check it.

make sure your connections are good and not loose