Can bad battery cause issues
Elder User
Joined: Jun 2012
Posts: 757
Likes: 0
From: 7th realm of hell, Va.
Yes, If the battery has a bad cell it can cause the alternator voltage to be low or fluctuate. Low voltage leads to poor spark.
To know if a low voltage issue is causing your issues read the voltage across the battery terminals with the engine running. If you are reading a constant 13-14.5 V with the engine running then the battery is not causing your issues. If you are reading less than 13 then have the battery check at one of the auto stores. If the battery tests good and is fully charged then pull your alternator out and have it tested. If that tests good then check you wiring and coil, points, wires. etc
this is how I would go about checking everything
matt
To know if a low voltage issue is causing your issues read the voltage across the battery terminals with the engine running. If you are reading a constant 13-14.5 V with the engine running then the battery is not causing your issues. If you are reading less than 13 then have the battery check at one of the auto stores. If the battery tests good and is fully charged then pull your alternator out and have it tested. If that tests good then check you wiring and coil, points, wires. etc
this is how I would go about checking everything
matt
Cargo Master
Joined: Sep 2005
Posts: 2,954
Likes: 64
if the battery is good enough to start the car, it wont make it run rough at idle.
Thread Starter
|
New User
Joined: Jan 2014
Posts: 11
Likes: 0
Yes, If the battery has a bad cell it can cause the alternator voltage to be low or fluctuate. Low voltage leads to poor spark.
To know if a low voltage issue is causing your issues read the voltage across the battery terminals with the engine running. If you are reading a constant 13-14.5 V with the engine running then the battery is not causing your issues. If you are reading less than 13 then have the battery check at one of the auto stores. If the battery tests good and is fully charged then pull your alternator out and have it tested. If that tests good then check you wiring and coil, points, wires. etc
this is how I would go about checking everything
matt
To know if a low voltage issue is causing your issues read the voltage across the battery terminals with the engine running. If you are reading a constant 13-14.5 V with the engine running then the battery is not causing your issues. If you are reading less than 13 then have the battery check at one of the auto stores. If the battery tests good and is fully charged then pull your alternator out and have it tested. If that tests good then check you wiring and coil, points, wires. etc
this is how I would go about checking everything
matt
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Does the truck have an alternator, or a generator? Points and condensor, or electronic ignition? I would say yes, a weak battery will contribute to a poor idle and performance. Not the primary cause, but a factor. Infrequently driven, short trips, means sulfated battery, weak ignition.
Does the truck warm up in a reasonable amount of time? Y blocks are known to be cold-blooded, but that's not really the case exactly. Everything adds up - fouled plugs too, and once they are fouled they don't get un-fouled on their own.
Does the truck warm up in a reasonable amount of time? Y blocks are known to be cold-blooded, but that's not really the case exactly. Everything adds up - fouled plugs too, and once they are fouled they don't get un-fouled on their own.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
The BEST tool if he has problems, and even if he doesn't, is get a vacuum gage. They cost maybe 20 bucks. Get one with a large face that's easy to read. You don't have to memorize everything they are capable of doing, that's what the manual is for. And the things they can diagnose is amazing. I don't know how anyone can work on these things without one. They are called "the poor man's Sunn machine" for a reason. It will tell you the overall health of the engine. While it's not a compression tester, if a V8 pulls 19 or 20 inches of steady vacuum, then compression is good, no? It will diagnose valve problems. You can set engine timing and carburetor idle mixture accurately, etc.
Thread
Thread Starter
Forum
Replies
Last Post
Dave_in_desert
1961 - 1966 F-100 & Larger F-Series Trucks
7
Feb 26, 2020 04:40 PM
