For all the TB EFI people....

[paint2361]

I have a Pontiac 400 with an EZ-EFI system and a dual plane intake.
Pulled my heads off and noticed the cylinders on one side of the intake plane were lean.
What are the thoughts of a dual plane vs single plane with a TB EFI system.

[another69]

What makes you think that they were lean?

[paint2361]

What makes you think that they were lean?

The exhaust valves were red on only those cylinders.

[yellow1098Greg]

Just curious.....what was the reason for pulling the heads? Was it a performance issue related to the efi?

[paint2361]

Just curious.....what was the reason for pulling the heads? Was it a performance issue related to the efi?

Building a new short block. Reusing the heads and intake. I have been using the FAST EZ EFI for over 3 years. So far it has been very good. Always fires right up.

[Mr Nick]

Interesting, I have the EZ EFI on my Olds, but have not pulled the intake or heads since install. I don't think the fact that it's TB EFI would be a cause (or solution) of a bank running lean.

Vac leak on that half of the intake? Dirty injector on one side firing too much or not enough fuel? Depending which side the potential problem is on, and where you O2 sensor is, the computer may never know. Same thing could happen with a bad jet/needle on a carb.

[another69]

So one side of the intake plane means 2 cylinders on one bank and 2 on the other, right? Were the other cylinders overly rich? In the future you could add an O2 "gauge" on the bank without the ez-efi O2 sensor. Or just swap the O2 sensor to the other side to see if it is similar or way off. I really doubt that the efi is adding to the fuel distribution problem that you may have though.

[paint2361]

I did notice a pipe plug in the intake on the side that I lean. It may have a small leak....