Idle trouble - Looking for help

[charles_chinaski]

Hi all,

New to the forum; posting for my dad. He's been restoring his 1929 Model A and has run into an issue getting the alternator (tried the original generator, too) to "kick in". The truck only runs with a foot on the throttle (takes at least 30 seconds) until the alternator starts to put out amperage, then it idles nicely. How can he get the alternator to start cranking right away?

Other things he's tried: drained the gas and changed fuel filter. Also has changed carburetor.

Please see the video here and watch the needle jump around the 7 second mark and it idles fine (click the speaker in the lower left hand corner for sound):

https://i.imgur.com/cRwexVg.mp4



Thanks for your help!

[Jacksonlll]

It’s just fine. It just takes a higher RPM to kick it in. Rev the engine, or just take off in first gear and it will kick in.

[Dick Steinkamp]

Are you saying the truck won't idle UNTIL the alternator kicks in...

OR that it takes the alternator 30 seconds to start charging...

or both?



I'll assume both.

I believe they are unrelated observations. When starting a Model A cold, the spark should be fully retarded (left lever on the column fully up), the throttle should be advanced a couple of notches (right lever), the GAV should be open about 1 turn. Switch the key on, engage the starter, pull the choke out for a second or two and it will start and run at a fast idle. Then advance the spark about half way. Without the step of advancing the throttle a couple of notches, it will not idle fast enough when cold to run. Once it starts to warms up, you can return the right lever to idle and close the GAV down to about 1/4 turn open.

The alternator not showing charge initially is likely due to a the use of a single wire AC Delco type alternator. It has to "self excite" to start charging and won't do this until it sees 1,000 to 1,500 RPM. This is generally not a problem. Just "blip" the throttle (after it warms up at fast idle), or just drive away. Your first acceleration to normal road speed will get the alternator charging.

[MAG]

You did not say if it was a 1 wire installation. Assuming it is, it may be working correctly. The video is not long enough to see if the alternator is staying in the charge mode sufficiently. Working properly, immediately after starting the engine the charge rate will be very near max (20 amps) and will start cutting back very shortly if the battery is fully charged. Yours appears to do that.
"One-wire" alternators require the engine to be reved in order to begin charging. Some one- wire alternators will continue to charge alt idle. Although at a lower rate.
One-wire regulators in the alternators, if made in China, are known to Mal Function and/or to fail completely. If that is the case, locate and install a U.S. made regulator.

[burner31]

Noisey engine, sounds like something is ratting or loose.
Try a new "American" regulator/cut-out, dump that foriegn garbage.

[charles_chinaski]

Sponsored Links (Register now to hide all advertisements)

Thanks all! I'll forward your responses to my old man and have him give it a shot. I'll update when I have more information.

[canadian]

Originally Posted by charles_chinaski

Thanks all! I'll forward your responses to my old man and have him give it a shot. I'll update when I have more information.

if you are using a self exciting Alternator , most common G.M style, make sure to use the special pulley available from most Suppliers, I have my 29 modified to 12 volts and it starts charging with very low RPM