Engine missing at idle in sync with alternator gauge

[coop]

Hi i am a new member to the forum. I have a 1970 Camper special w/390. When I start the truck the engine slightly misses at idle and the alternator gauge pulses to the right in sync with the miss. If i in crease the engine speed the needle will fall into the center and the miss goes away around 1000 rpm. When it is dark and the head lights and gauge lights are on they will also pulse with the miss and then even out once the speed is picked up. And when you come to a stop the lights will dim and then brighten once i move along. My dad had replaced the voltage regulator about a year ago and I have purchase the truck since.Does anyone have any suggestions?

[Dragon]

Welcome. Thanks for putting the truck info in. Many newbies think we can mind read here

About normal the alternator does not put out much at an idle sometimes just 50 more rpm on the engine at an idle makes the pulse disappear on normal trucks. Meaning not missing ones. Cleaning all the Alternator, regulator and battery connections where they tie to the solenoid helps reduce loss through corrosion and gets more power through.

P.S. Corrosion will be there whether you can see it or not to some degree.

[coop]

Thanks Dragon I will do what you suggest. thanks for the info.

[mouse]

I fix this problem on my dads 66 cadillac by upgrading to an newer alternator with internal voltage regulator, no hard wiring involved just take the field wire from external regulator and hook it up to the field in the pig tale for the new alternator and the second in the pig tale goes to the positive post on the alternator, the rest of the wires on the old regulator you don't need

[Dragon]

Just get a 3G, 4G or 6G and you only have the BAT wire.

[mouse]

I upgraded to a one wire 100 amp alternator in my fiero and put the old one in the cadillac