misfiring

[fastgary]

I have a 87 GN that I'm having problems with. It runs smooth up to redline if you bring it up part throttle. but if you run it up full throttle it starts misfiring. I'm not sure if it is fuel related or ignition related. Does anyone have any suggestions.

Thanks, Gary

 

[scottyb]

Start with plugs, coil pack and wires. both times I had this problem it was the coil pack.

 

[fastgary]

I changed the plugs and the wires already. Is there a test to check out the coil pack or should it just be replaced?

Gary

 

[Roger]

Caspers sells a very good coilpack & ignition module checker.

 

[scottyb]

A basic test is to check the resistance between towers and connectors on each coil. I don't have the specs. Autozone will test it for you. Mine was out of spec on this test. I have also read that it can pass this test but still be bad. It's a start.