VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 backfire through carb

I'm having trouble getting my engine (1930 194) to start up. All I seem to get is cranking for 2 minutes, a huge backfire through the carb, crank for 2 minutes, backfire through the carb. I've put on new plugs, wires, points, condensor, rotor and cap to no avail. Any help is aprreciated. -dave

Timing?

Check to see if your distributor is 180 degress out. And, make sure your spark plug wires are in the correct firing order. The firing order should be: 153624

How do I check to see if my distributer is 180 degrees out? I've checked the firing order of the wires and I'm pretty sure they're correct. Well, I've got the firing order correct(153624) but I'm not sure I've got #1 on #1. However, I spent quite awhile moving the wires in order around the distibuter with no luck.

One way to check which distributer position is #1 is to put the timing mark on the flywheel on the pointer, pull the valve cover and check to see if the rockers for both intake and exhaust on #1 are closed (loose). If they are both closed you should be on #1 and you can observe which way the rotor is pointing for wire placement. If one of #1 valves is open, check #6 and its valves should be closed. Wire the firing order stating with #6 in this case.

George

Since the engine can be timed off of number one or number six, make sure that the pointer is on the 12 degree timing mark, and that number one cylinder is on compression. Then check to make sure both number one valves are closed. After that, check to see if the rotor is pointing to the number one tower on the distributor cap. If it is pointing to the number six tower instead, then your distributor is 180 degrees out.

The correct location for the number one spark plug wire is approx. half way between the six o'clock and the seven o'clock positions on the distributor cap.

Yeah, you gotta remember the flywheel goes around twice for each time the rotor goes around once. so you have a 50-50 chance of being 180 degrees off when the timing mark is in the window. You gotta have three things together to have the ignition in time.

(1) the flywheel mark in the window
(2) piston #1 at TDC, on the compression stroke(both valves closed).
(3)The rotor pointing at the post for the #1 sparkplug wire.

Of course the timing gear on the cam and the timing gear on the crank must also be in correct alignment, and the camshaft turns one time for every two revolutions of the crankshaft.

I was wondering, do you have a good strong spark at the sparkplugs?
I asked because...once I put a new short rotor on a distributor with a tall distributor cap a 51 Chevrolet. My car did that, crank and crank, nothing, then every so often BOOM a big backfire out the carb.

Have you checked the valve clearences? too tight on the intake valves will do the same thing.

Thanks guys, I'll check the timing. I'd say I have a good spark at the plugs--not enough to light up the garage, though. I bought all the ignition parts from Kanter at the same time and they all match physically with the old parts that were on the engine.

Also, Junkyard Dog, you indicate the correct location for #1 spark plug wire is approx half way between 6 and 7 o'clock positions on the distributer. From which direction are you looking at the distributer? If I'm looking at the engine with the radiator on my extreme right and the car's body on the extreme left, I have my #1 at approx 5 o'clock now.

Yep, that's how I'm looking at it too. Okay, to make things easier, the number one tower on the distributor cap is directly on top of the embossing that is on the bottom lip of the distributor cap that fits into the notch on the top of the distributor. Also, the number one tower is to the direct right of the left spring clip on the distributor body that is one of two clips that holds the distributor cap in position on the distributor body.

By the way, on the tune-up parts (i.e. points, rotor, condenser, and cap) they are all available from your local auto parts store on a stock order. Just so you will know the next time that you need tune-up parts.

It runs! I checked the timing mark on the flywheel, #1 cylinder was at compression, valves closed, rotor pointing almost at #3 tower(assuming #1 tower is at the notch). I moved my plug wires pressed the starter, a few seconds later it fired up. I moved the distributer conterclockwise until the grease cup hit the block to get it running relatively smoothly. So, I have 2 questions: First, should I take out the distributor and try to put it back in so that the rotor is pointing to #1 tower? and under what circumstances whould I retard the spark by pulling the spark button on the dash? Thanks again, -dave

Yes on your first question since you have the car out of time. Even with the timing set at 18 degrees you should be able to pass your finger between the grease cup and the side of the engine.

You can pull out the spark knob thus retarding the spark each time that you start the car if you wish. Doing that will make the car start easier when you have your timing set correctly.

Thanks alot! It was a relief to be able to get it running!

I'll bet. Now that you know the problem it will be an easy fix.