VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt Starting problem

I have a 6 volt system in my Deco truck. It has started and run well for many years now. Good grounds of proper size and type. Extra grounds in fact. Rebuilt starter with a new starter switch. (Foot stomper type.) My original Starter was rebuilt this summer by a respected old timer.
Here's the issue. When I start the truck after sitting for a few days, it will crank and crank. No fire in the hole. Eventually, as I let up from the starter pedal, the engine will start. Almost as though the starter is taking too much juice from the ignition. Warm starts are fine.
The ignition is Pertronix. I know, I know. You all want to point to that and have me go back to points. Not happening. So moving on, and for the time being, assuming it is not the Pertronix, what should I be looking at? Thanks in advance.

I have found that the gas evaporates from the carb. bowl and It takes forever to refill. An electric fuel pump solved this issue for me. Not sure If this contributes to your problem, but you can test the theory by priming It before starting. If this doesn't help try switching back to points ( just as a test) and see If It helps.
Richard

I also have an auxiliary electric pump, but rarely use it. I find that if I pump the accelerator pedal 3 times before trying to start it cold, and choke it sufficiently, it starts right away. I think PU Guy is correct about the gas evaporating.

Where in the system do you put the electric fuel pump? In front or after the manual one? I have a 6 volt electric pump that I bought to put on, but my engine builder drilled out for the manual pump (Military 302 GMC) so I never installed it. I'm assuming a toggle switch for a pre-start shot and then shut it off?

They are better at pushing than pulling, so, in front of the manual pump as close to the gas tank as possible. Yes, a toggle switch is needed, since it Is not neccessory to run It all the time.
Richard

Yes between tank and mechanical pump. Push button switch is much better than toggle. Have to keep pushing to get the pump to work. With toggle have to remember to turn it off.

Assuming good battery and correct size POS cable even old timers have bad days. Check the starter draw.

Hi,
Had a similar problem with my 28, long cranking to start, no probs when hot.

Did the following

1. Overhauled carby which improved slightly, as the choke was not operating correctly.

2. Removed battery top kill switch that was not connecting properly.

3. Replaced Battery to Earth cable, that was suspect.

Results were stronger cranking, but starting still required excessive cranking.

Then re set the ignition timing, and starting improved out of site.

Car can now sit for over a month, and will fire on first few turns.

Regards

Ray

"Assuming good battery and correct size POS cable even old timers have bad days. Check the starter draw."
Help me out here. How do I do that all by my lonesome? Ground and starter post during cranking?

Checking the draw can be relatively easy if you have a foot stomper starter switch a clamp on ammeter. Just grab the linkage where it contacts the switch on the top of the starter and push (or pull) it to engage the switch. With the other hand position the clamp on ammeter over the positive cable to the starter and read the amperage with the starter spinning. Of course have the transmission in neutral and blocks in front and back of the wheels. If you don't have the ammeter then find someone that does. The ammeter on the dash does not read current to the starter only all the other electrical stuff.

If I remember correctly, you should be looking for 400 to 475 amps of draw on an engaged 6 volt starter.
Richard

Much thanks gents. I now know what a clamp-on ammeter is, thanks to you and Wikipedia and Sears. I'll attempt that this weekend if I can track one of those babies down.
And should it draw too much, the starter component at fault would be........?

CORRECTION: I just looked It up and the magic number is 525 amps.
Richard

Make sure you have enough voltage at the coil + terminal when cranking engine. Also, make sure you have a good ground for your distributor. I had similar issues with a Pertronix unit on a '47 F**d. A ground wire solved it for me.

A similar Pertronix problem on my 52, called the tech line and was told that with a 6V system you need at least 5.3 (from memory) volts at the + side of the coil. Any time you have to run the starter longer than usual will pull the battery down and that effects the voltage available at the coil, letting of the starter button raises that voltage.

I agree with that. I believe I have solved the problem for now. I tinkered with it this morning and did a few things. There was a larger than necessary washer on the linkage arm to the starter. i changed the. Then I started looking at the wires to the starter terminal. I pulled hard on the ignition lead, and voila-separation. I changed that and tested it out and got instant startup. I put a star washer on as well. So that's a wrap for today, I thank you all. Fuel pump will stay in it's box for now, I didn't buy a clamp-on ammeter yet, I didn't junk the Pertronix, so I'm happy at the moment.