tbi 454 rich on 1 bank

[black dawg]

On my burb that I converted to tbi 454, I had the plugs out to do a compression test. Left bank plugs (the side with the o2) looked good to slighty lean, and right bank plugs are rich. I dont see how this can happen, it has a dual plane (edelbrock performer with stock tbi adapter) intake. It does have dual exhaust (with a small crossover).

Any ideas?

and compression was a very even 140.

 

[454Sub]

Well, since obviously the engine changes fuel on both banks depending on the input from the O2 sensor, I would say its not getting equal air/fuel from the intake. Or, possibly you might have a bad injector on one side that is not tripping a CE light. Have you checked the spray pattern?

 

[dyeager535]

I don't think the dual planes feed only one side of the motor per injector.

I can't see a situation where one entire bank can be lean and one can be rich, without some crazy coincidence like all weak plugs, plug wires, cap terminals, etc., ONLY for one side of the motor.

 

[black dawg]

It is dual plane, so 1 injector feeds 2 holes on each side.

All the plugs on the right bank were black, and 3 plugs on the left bank looked really good, and one on the left bank was maybe slightly leaner than the rest on the left bank.

I will drive it with fresh plugs for a couple weeks and then check it again.

 

[eagle mark]

Where did you hook the PCV hose?

Vacuum leak, EGR valve issue...

 

[black dawg]

pcv is hooked at stock location at throttle body. No egr.

I plan on investigating for vac leaks, all the intake bolts are nice and tight, but I am getting some oil leaking through on the right side.


I just remembered, that awhile back after lots of idling thing thing was oil smoking out of the right pipe. I wonder if the intake ports are pulling just enough oil to darken the plugs some.