SC lean one side rich the other, help?
 

Changed plugs in my 1980 stock SC drivers side plugs look to be running somewhat leaner than Pass side, any ideas? Car runs great under full acceleration pulses at crusing speeds in all gears.
Thanks in advance
Rich

Hello Rich.

Do you have the factory exhaust ? Are you sure it is not oil fouling ?

Factory exhaust not oil fouled just more carbon on one bank then the other.
Thanks
Rich

I think I'd start looking at the intake runners on the drivers side to see if there's any indication of a vacuum leak or possibility of one.

Could check injectors. If spray pattern isn't good it could be do to a clogged / cruddy injector = lean condition in that cylinder.

Factory exhaust not oil fouled just more carbon on one bank then the other.

Hello Rich,

Since there is very little "bank" related plumbing with CIS, I would be thinking variations in exhaust and cooling. I would drive it for at least 10 miles, then get underneath with an IR thermometer and check the cylinder head temps. Consider blocked/dirty cooling fins, broken air deflectors, uneven heater plumbing, blocked/ damaged exhaust. There is some normal variation in backpressure in the exhaust.

you can measure the fuel volume of each injector.
pull all the injectors with lines attached, put each one in a conatainer all at the same time. turn the key on, raise the air flow plate for about 30 seconds. then measure the amount of fuel from each inlector. i weighed mine using a small postal scale, i found one was putting out about half the fuel due to a bad injector line.
i used a common container on the scale and poured the fuel into it.
if you have a problem, remove the injectors and test the lines to eliminate the injectors. actually, mine was such a big problem, i could tell with out weighing there was a problem. the longer you hold the plate up, the more the problem may show i would think.

also check compression, would low compression make it appear to be rich?

I am with Scott. Check the intake manifold. You might even be able to hear it.

Then move on to injectors.