running rich on one side? Two part question

[evilways]

I pulled the truck out of the garage tonight and she had to sit outside for several hours, the temperature outside is 28 degrees. When I started her so she could warm up, I went to the rear to watching the steam puff out the side pipes, or should I say pipe. I have true dual exhaust setup with mufflers; they exit out just before the rear tires on each side.

The problem I noticed is that the driver side is pouring out steam constant, but the passenger side is only puffing steam intermittently. Probably 4seconds of steam and 2 seconds no steam. Shouldn’t it be constant on both sides?

Also I am running rich out of my driver side pretty bad and not so much on the passenger side, how is this corrected and does that have to do with the steam in the cold weather that I am seeing.

[Tmiller]

Are you running a dual plane intake?
If so I would guess that your idle circuit on the driverside is out of adjusment or dirty.
The steam is only from the amount of moisture collected in the exhaust as it sets, being that the driverside is rich probably goes with the fact that its running more steam on that side, maybe more carbon buildup in the exhaust for the moisture to build up on.

[cdowns]

what make you think its running rich on one side?are the plugs black?

[68gmsee]

Re: first problem.

Check the color of the steam as it's coming out. If it's white more than likely it's accumulated moisture or condensation. It should stop after the engine warms up. Moisture is also produced by combustion and the heated exhaust will cause condensation "smoke" sort of like those high flying jets in the sky.
Now, if it doesn't stop and if you're losing radiator water, then you probably have a leaking head gasket.

On the other issue, unless you have some sort of separate fuel delivery to the banks as Tmiller said, the gas is pretty much premixed in the intake manifold and it should be delivered equally to all pistons. So, check the spark plugs as Cdowns mentioned for signs of problems.

[Senator350]

any chance of one half of your primaries (one) mixing a bit differently? (I'm not carb guy, just a stab)

carb specs? intake specs? color of plugs after a clean plug run?

[El Jay]

Are you running headers or cast iron manifolds?

Back in the olden days some cars/trucks had a heat riser between the manifold outlet & the beginning of the exhaust pipe.
They had a bimetallic spring to open them when the engine got warm, but they always seemed to crudded up & would stick, usually in the closed position.

[Bus Ted Knuckle]

is it cold where you are? It is probably just condensation burning off inside the exhaust.

[Tmiller]

I ran that edlebrock carb and manifold back in the day and was always cleaning and adjusting the idle air screws.
I'd suggest pulling the idle screws out and spray a bit of carb cleaner in their holes, clean off the adjustment needles and reinstal them. Screw them in until they just touch the seat then back them out 2 turns, this will get them close. Put a vacume guage on to read manifold vacume, start engine, one side at a time screw in then out the adjuster until you get the most vacume possible then do the other side, go back and forth a couple of time to make sure it just right.
I use to do this about 2 times a year just to keep it running right. This should help the uneven fuel mixture from left to right banks with the dual plane manifold.

[Green Machine]

Keep in mind that each side of the carb feeds 2 cylinders on each side, not just the cylinders on its own side.

[Senator350]

so, a driver/passenger difference in fuel mixture would have an equal effect on both sides.

so, the driver or passenger primary isn't the culprit at all.

that was really just a stab... wasn't picturing an intake in my head, but makes sense now.

[Tmiller]

Sorry never relized, been a long time since i ran that intake. Sounds like a weak cylinder more now.
I still suggest cleaning and resetting the idle circuit though. I was doing it often, I knew it was time to do so when it would load up at idle, clean it and would be good for a few months.
Looking at the manifold It may be possible that the fuel may be pooling and running into 3 & 5 where the standing fuel would have to run all the way across the manifold to get to 2 & 8,at idle i don't see enough port velocity to do that, just thinking out loud.
It only take 10 minutes to clean and readjusts these, less indepth as a leak down test.

[evilways]

I am going to pull the plugs and make sure they are all clean and the gap is still good.

As far as the carb, it was just completely cleaned and rebuilt by me and a friend a couple weeks ago, so I don't think that the needles would be dirty yet.
I don't have a spacer as Edelbrock recommends so with the performer carb and the performer intake I figured this would work very well?

I have yet to pressure test the coolant to see if a head gasket is leaking, my only real fear is that this engine was supposedly bored over 30, and if for some reason it is greater than that the possibility of pin hole in the cylinder walls have me nervous.

[68gmsee]

Originally Posted by evilways

...... my only real fear is that this engine was supposedly bored over 30, and if for some reason it is greater than that the possibility of pin hole in the cylinder walls have me nervous.

Not likely at .030 over unless someone screwed it up. Some of these old engines can be bored up to .060 over. You would see a loss of coolant if you had a cracked engine block or pin hole.