1&4 cylinder no spark

[twitty]

I have a 93 lumina 3.1 I changed plugs, wires and coil pak 1&4. Sometimes the car starts with all 6 firing. I drive a few blocks 1&4 quit firing. Other times i can drive a few miles before it quits firing. The car never dies though, Just runs rough due to only 4 cylnders firing. Any input would be greatly appreciated

[maxwedge]

Welcome to AF. More than likely this is the ign module, assuming all else checks out.

[kevinb70]

1 and 4 run off the same coil on the L82 3.1L I suspect same for your year. replace the 1/4 coil after checking it for proper resistances / loose or corroded connections (the coil to ign module blade connectors).

replacement coil doesnt mean it works. use a multimeter. but ya after that go for replacing module

[Bearwulf]

Since Twitty has already replaced the coil, I agree with MAXWEDGE next is the ign. module replacement unless they take it to a shop to get it checked first.

[twitty]

Thanks for the info. The prongs on module look good. I guess I wll pull it and see if there is anything happening on the backside. And I agree Bearwulf, Grandparents do rule. Also do you have that tboned 91 euro?

[Bearwulf]

Yes I still have the t-boned '91. Take the IM into shop or even some parts houses for testing.

[twitty]

OK I pulled the mod and had it tested. Yup it was bad. Installed a new 1 The car runs fine. Thanks for the help fellas.