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Efi again.......


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i can't get my78 280z to stop fouling the plugs.

The injectors weren't getting pulse and i replaced the

ECU. (thought that would solve probs)It had electrical woes not engine related(i think)

but i am out of ideas. What are the common causes of carbon

fouling on the plugs. It seems to be running rich but what do i

know. Could it be the ignition module? Is that common? I just need a place to start over with.

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Carbon fouling possibilities that come to my mind.......

* Weak spark

* Oil blow by due to worn rings / low compression

* PCV not operational ( stuck open )

* Too low of fuel octain rating

* Timing to far retarted ( incomplete burn )

* Wrong heat range of spark plug

* Too cold of thermostat

* Worn out / hardened / cracked valve guide seals

- Those are the items that come to my mind as the possible

sources of carbon fouling on plugs.

I welcome others to add to and/or correct the above.

- Jeff

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