The Stovebolt Site Forums The Shop Area Engine Shop Starting issues with my 235 (1957 3100)

I need some guidance, please. 1957 3100, 235, was running fine. Easy to start. Then not. Lots of cranking and it would finally start. After cranking it seems to run fine. No hesitation, higher revs OK. Appears to have spark and getting fuel. Starting is the issue. Using a very short blast of starting fluid, it starts right up and runs well. Shut it off and immediately attempt to restart. No luck. Another blast of starting fluid. Starts, but no restart. Coil, fuel pump, points, cap, rotor, condenser all less than a year old. Carb is a Rochester B1, 7005921. Maybe not a hot enough spark to initiate a start without the fluid? Any and all ideas would be appreciated.

As a troubleshooting aid, put a jumper wire between coil + and either battery + or the battery cable on the starter. See if it will start then without the starting fluid. If it does, the problem is most likely in the ignition bypass circuitry.


Do not leave the jumper there once you've done the test. Burnt points and a run down battery may result.

3100inSantaFe - Your topic will get the most responses and help in the Engine Shop so it's been moved there.

If it will squirt gas down throat of carb with hand operation of throttle, I agree with Bill and you , weak spark. "Less than a year old"....now-a-days parts can come out of the package and be no good. You can test spark, in the dark, at one of the plugs to see a snappy bright spark. Color does not matter.

Bill and bartamos, thanks for the tip. I will give that a shot in the morning. That should be an easy test.
I will update you then. Thanks! George (Yeah... I hadn't thought about the voltage differential at startup!)

Gentlemen, you are geniuses Jumpered and it fired right up. Now to figure out where the bypass is snafu'd. (I am sure that is a technical term!)

Thanks!!!

G-

Next step depends on if you have a stomp starter (was available in GMC sixes through 1959, I don't know about Chevys) or a key start.

Bill, it is a stomp start. Which leads me to the next question. After I did the jumper, the truck now starts every time. Good, but unfortunate. I pulled the ignition switch to check connections. All appear tight. And it is a new replacement switch, FWIW. So, starting (no pun intended) at the starter, I have 12.5 or so volts at the battery connection. Upon stomping the starter I have about 11.1 volts on the connection that leads to the ignition switch. Is this correct? Should I have 12.5? Wondering if the stomp switch could be intermittent and at times dropping the start circuit to an even lower voltage. Did the question make any sense? Thanks for your assistance!

The load on the battery will drop the available voltage while the starter is running. Does the starter have the switch with the small side terminal that bypasses the ignition resistor? The resistor is supposed to drop the running voltage to about 9-9.5 volts to protect the points from being burned. If not, you need to purchase one from somewhere like Rock Auto. They call the switch a "solenoid", BTW. Wrong name!

www.rockauto.com/en/moreinfo.php?pk=445442&cc=1489472&pt=4188&jsn=930

Jerry

Jerry, the running voltage is about 9.5 as you mentioned. Starting from the beginning, the truck would not start. Long cranking....maybe. A blast of ether would start it. It had been running great. Upon a suggestion obtained here, the did a jumper from the battery + to the coil+ and without ether, it started immediately. My thought is that the starting circuit was not getting enough voltage to start the engine under normal conditions (no ether) but there was enough voltage to keep it running. Now the puzzling part. The jumper was in place maybe 5 seconds. I was thinking maybe a loose connection at the ignition switch. I had replaced the switch about 6 months ago. Everything seems tight. I tried to start again, and it fired right up. No ether, no jumper. I would rather not 'assume' all is good. The start circuit gets its power from the stomp starter. Could that be intermittent. Hence my question about the start circuit voltage coming from the stomp switch. 12.5 going in, should there be 12.5 coming out or is the 11.1 that I have correct? With the start circuit wire (violet) disconnected at the switch, I get 10.9 there. I have worked on British cars for years. Lucas systems can be troublesome and only fail when it is cold and rainy. (Intermittent wipers!!!_) I hate to assume that the jumper episode with this Chevy was enough to cure whatever ails it. Your patience and expertise are appreciated. Thanks!

The "bypass" voltage to the coil while the starter is engaged comes from the stomp switch on the starter. 12 volt stomp switches have a small terminal on the side. There should be a wire from that terminal to coil +.

I can waste a few billion electrons trying to explain the system on the forum, and hope you understand what I'm saying- - - -or spend five minutes with a telephone call where we can have a 2 way conversation- - - -your choice.
Jerry