has anybody seen a distributor turned this far? 75 chevy 350?

Question

we recently got my truck running, my friends dad got it in time and it runs fine but the idle adujstment on the carb is either high or too low. I think he turned it this far to compensate for being a couple teeth off. check it out, what do you think? Its got a high rise intake and 4:10's I need to be sure im gettin the most MPG I can. http://i114.photobucket.com/albums/n272/hunterman09/topviewofdistrib.jpg

Answer 1

I own a shop, and work on old Chevy's all the time. Nice carburetor! Something don't look right about the distributor. It seems to be in the wrong notch, or the plug wires are a notch off on the cap. After looking again I see what it is. The wires are in the wrong spots. Your #1 should be moved one space clockwise, and then the rest moved following it. Once they are moved, the distributor may have to come out to get it in the right notch. Do this: Remove the #1 spark plug, put your finger over the spark plug hole, and have someone just bump the starter until it blows your finger off the hole. Now, turn the engine by hand until the timing marked 0 on the balancer aligns with the pointer. This will be top dead center, or zero degrees on the balancer. Remove the distributor cap, the rotor should be pointing towards the #1 on the cap. If you loosened the hold down bolt, you should be able to turn the distributor, and sweep all the way from before, to after on the cap position of the #1. If you can't, then it's definitly in the wrong notch. If it was in the right hole, the distributor cap would be square with the back of the carburetor. If you put a straight edge (a ruler) across the flat part of the coil housing, either end of the ruler should be pointing straight at the fenders on either side, not one more than the other. This would put the rotor a few degrees before (the rotor turns clockwise) the #1 plug hole on the cap. See how your wires are having to go a long ways to the point of stretching them out of shape. Even your power wire for the distributor is stretched till it is almost at a breaking point. Remove the distributor, and put it in the right notch, and use a long screw driver to turn your oil pump so that it will allow the distributor to go all the way down when you put the distributor in. Be careful to not drop it down in the motor! When its in the right notch your wires will look right, and the vacuum chamber will be in the correct position. You should be able to hit the starter, and it should fire right away, without moving the distributor much at all. I run my timing as high as I can without it spark knocking, and it will start without grunting too much when its hot. Check the vacuum hook up for the distributor. There should be no vacuum on that line until you hit the gas. If there is vacuum on it all the time, its the wrong source. You need ported vacuum, meaning vacuum comes on it when you hit the gas.
I hope this helps get you going in the right direction.
Glad to help out, Good Luck!!
Part# 2:
After I thought about it, the sure way to tell your distributor is in the wrong groove is; You can't get it to time with a timing light. You won't be able to find the scale on the harmonic balancer to align it up with the pointer. If the idle speed goes up and down, then suspect the vacuum hose for the advance is hooked in the wrong place, or you may have a vacuum leak under the carb. Did you maybe use the wrong mounting gasket for the new carb, or does yours need a spacer block that is made to adapt it to that intake? I put a one inch block under mine, with a Mr. Gasket base gasket under the carb, and the block. This spacer is made of aluminum, and makes the carb run cooler, plus it gives the truck more power. Enough power to tell the difference when you nail the gas. Sometimes the fuel will boil in the bowl in the carb, and it needs this to keep it cool enough to control the idle speed better. From looking at the picture, your hose (that goes to the vacuum advance) should be in the front where the one is plugged off with a black cap, to the right of the fuel filter. Something don't look right about your mounting gasket, maybe up side down? Have fun!!!

Answer 2

Country Boy, The vacuum advance canister should be pointing straight at you as you lean into the engine compartment over the right front wheel. Pull the distributor out reach into the hole on your intake manifold and turn the oil pump counter clockwise with a long screwdriver. The distributor should slide in all the way. From your explanation it sounds as if you should remove the distributor cap and rotor and check the weights and springs. If you see any signs of rust on top of the weights remove the springs and weights. If you see any unusual wear in the weight holes replace them along with new springs. If you have a shop with a distributer machine have them spin it and determine what the advance degree curve is. Standard GM. distributors have a long mechanical advance built in for emisions purposes. On the opposite side of the weight / spring plate there is a pin that slides back and fourth in a curved slot during RPM changes. Chevys like a shorter mechanical advance curve. Any speed shop has advance curve kits. It'll contain new weights, a few sets of springs and a bushing. Punch out the roll pin on the distributer gear and install the bushing on the pin on the bottom of the weight plate / distributer shaft. Put every thing back together and spin the distributer again. You will now have a shorter mechanical advance curve. Write these numbers down and compare the readings from the first spin. You will have less mechanical degrees. You will now be able to run more inital advance 10 - 12 degrees. The total advance will be no more then the standard numbers. Do an inches of mercury / vacuum test with the guage hose on the bottom fo the throttle plates. Jot that number down. If you haven't already done it hook your distributor vacuum canister hose to a vacuum source benieth the throttle plate. You will have full vacuum advance while the engine idols. To be sure your vacuum advance cannister is working put a finger benieth the distributor directly on the canister shaft where it enters the distributer. With the motor idoling disconnect the canister hose. The shaft should retract out of the canistor. If it does not rev the engine up slightly to get more vacuum in the intake manifold the shaft should move back and fourth as you plug in and disconnect the vacuum hose. If there is no movement the canister is bad and this alone costs gas mileage. Go to your Chevy dealer and ask for a 236-16 vacuum canister if you have a lumpy cam in your 350. This canister will hold vacuum till it drops to 8 inches of mercury / vacuum. You can move the distributer up a degree at a time untill you hear the motor ping as you a slowly accelerate from dead stops. This setup will give you more throttle responce. It'll also squeeze as much fuel economy as possible.

Answer 3

If he used a timing light to time it I wouldn't worry about it unless it is in the way of your breather, it sounds like the only other thing to check is that the Vacuum Advance hose is connected to a vacuum port that is only open when the throttle is open, constant advance is not a good thing.

Answer 4

It is set too far,adjust your lean idle burn screws and back off the turn until smoothed out.Look at your exhaust if its black it is to far gray is about right.Water or fuel looking condensation is to fast.I wouldn't run it if it is missing teeth it will burn up your heads sooner or later or bend rocker arms.

Answer 5

The distrib is probably just installed a tooth off. If it's timed right just put a longer vac advance hose on it (which it needs) and let it go.

Answer 6

yes i have, its notch out of time on the distributor,you need to remove it and move it forward a notch,that will correct this,i bet it was hard to get in time also ,but that's all that needs to be done to it,good luck,

Answer 7

I agree, it is off by 2-3 teeth....

Answer 8

thats real close to being right, if it's running ok leave it alone, just make your adjustments on the carb.