awspeich

I have a 1971 Olds 350 that I just rebuilt, but I can't seem to get this motor to run. It will run sometimes, but barely. It spit and sputters, then runs for a few minutes, then dies. Once it dies, it won't start for an hour. Or like today, it will not even start at all. Turns over OK, just won't fire correctly. When it does run, it runs so rich that it'll make your eyes water. I've checked the timing when it would run, and the timing mark isn't visible with the timing light. Way out of time?? Not sure how that can be.

This is mainly a stock system, with a mild rebuild. New intake, more agressive cam, flat top pistons, standard points ignition, remanuf. Olds style Rochester 4BBL carb with electric choke. I had the timing 180 off initially, and it would not start. I fixed that, and believe the timing to be close. TDC of the crank is in line with firing the #1 plug on the distributor. I believe the valve timing is correct too, as I checked that when degreeing in the cam..and the motor has run.

But I'm stuck now. I do not know what else to check. I thought the fuel pump, but it gets gas, and will give you a shower when it backfires. Anyone know what else I can check? Any help would be greatly appreciated. Thanks! - Al

texasred

Check your firing order. 1-8-4-3-6-5-7-2 counterclockwise. (The counterclockwise fools most folks).

C.J.

awspeich

Thanks for the reply. I checked the rotation tonight, and it is correct as you noted. When I try to start the motor, with the crank at TDC (timing mark at zero) and #1 plug lined up with the rotor, it won't start. But if I turn the distributor about 40 degrees clockwise, that is when I can get it to sorta run. The small door in the distributor cap, used for adjusting the point dwell, faces the back of the carb. I know this isn't right, but it won't run when the door is in its 'normal' location. Any ideas? Thanks! - Al

Specman

Tricks of having learned the hard way...been there done that

Pull your #1 plug, and then put your finger over the spark plug hole while someoine jogs the starter in short bursts until you feel compression. Try to stop it with the piston at the top and then look at your marks. If they are not aligned or near the mark, your damper could have slipped giving you a false reading. IF you can get the piston accurately at the top put a crayon mark on the damper next to the zero mark of the timing marker plate.

Then either Reset the distributor, or move the wires around the cap until the rotor is close to the #1 wire. It should actually be a little beyond it going counterclockwise.

awspeich

Hmm..I'll check that tomorrow. Curiously though, how can the dampner slip? (I assume you mean harmonic balancer?) I thought when I put this on that it was keyed to the crankshaft. It was a new replacement balancer that I put on. I don't recall if the timing mark on it matched the old one. But seems to me I remember giving it to the rebuild shop so they could precision balance the motor, and I thought it only went on one way. None the less, at least it's another place to look. Thanks! - Al

Specman

If you look at how it is made you will see an outer ring bonded to the hub by a rubber separator. When the rubber breaks down the outer ring can slip and it is not always obvious. There are a couple different types too. All look alike but weights are different sizes and positions as are the marks.

It may not be the problem, but cheking all in relation to the #1 top dead center compression stroke will answer all the questions.

1976_Cutlass

By the oddest of coincidences, I was checking my harmonic balancer just this afternoon to see if it had slipped. The car in question was a 1989 Custom Cruiser with the 307 Y-code engine. Here's what I did.

You may have noticed during the recent elections that candidates put signs in the median strips of roadways. Real estate agents and other street spammers also put these signs all over the place. These signs are often made of plastic panels into which have been inserted a wire rod frame; two wire rods are then jammed into the ground to hold up the sign. Such rods are about 1/16" in diameter; I don't know what gauge that is. Take a straight section of this rod and cut it until it's about 18" long. The length really isn't critical, as long as it fits under the hood.

Disconnect the #1 spark wire from the #1 spark plug and remove that plug. With a breaker bar and a socket mounted on the retaining nut at the front of the crankshaft, turn the crankshaft until it's near, either before or after, top dead center for the #1 cylinder near the point of ignition. That is, the timing mark is near the index mounted on the front of the block. It helps if the harmonic balancer near the timing mark has been painted white to highlight the mark. Put the rod into the spark plug hole and hold the rod by putting your finger tip at the opening of the spark plug hole. By turning the crankshaft back and forth, you can feel the rod move up and down, corresponding to the piston's motion. Do not try to look at the timing mark as you do this; just turn the crankshaft and feel the rod. At top dead center, the rod will be stationary; it will neither rise or fall. When that happens, the engine is at top dead center for ignition in the #1 cylinder, regardless of the location of the timing mark on the harmonic balancer. Now look at the harmonic balancer. Where is the timing mark? Is it at 0 degrees? If so, the harmonic balancer has not slipped. If it is not at 0 degrees, then the harmonic balancer has slipped.

Repeat the procedure a few times to make sure that you have reached the point during the engine's cycle at which the rod is stationary. You'll be surprised how sensitive your finger tip is to motion in the rod.

You can do the whole procedure in a few minutes. Retorque the plug, reconnect the wire, take the socket and breaker bar off the retaining nut, and you are done.

Kennybill

You have to make sure it is on the compression stroke, not exhaust. I take a half of a paper towel, roll the corner and press it into #1 spark plug hole. Don't get to carried away but bunch it up enough to get a seal. This is so you can do this easier by yourself. See where your timing marks are, you may only have to bump the starter a bit. Standing outside the car while you reach in bumping the starter you can see when the paper towel blows out, that is your compression stroke. Do what u have to do to line the distributer to make it match #1 on the cap. When doing a timing chain change, the marks at Dot to Dot on an Olds is on #6 compression for firing, so u would put the distributor on #6, which is 180 degees from #1 compression top stroke. Ken