Charging and Running Problems
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Cross-Country
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Charging and Running Problems
I have a 1978 Ford f250 that has been Frankenstiened by the previous owner. The cab is a 1978 f250 and the frame and 390 motor are from a 1976 f250. I am having problems with the charging system for the motor. The battery has been tested and is fine. I have put a new regulator in a few days ago. The alternator seems to charge the battery but the battery slowly depletes as I let it run, maybe .01 volts every few minutes or so. Sometimes it will start up right away but most of the time if I don't drive it for 4 or 5 hours it wont start and I would have to jump it. I have a new alternator to put on but cannot get the bottom bolt out of the original alternator and am working on that. Also it has started to run like crap and would make some popping noises when idling and is very gutless when applying throttle slowly. I also replaced spark plugs a few weeks ago and have new wires to install today. Any help would be appreciated thanks.
Moderator & parts slinger
Joined: Feb 2007
Posts: 50,132
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From: S/W Missouri, Polk county
I would say your alt is not working. Bottom bolt, PB plaster, patience and impact tighten and loosen the bolt over and over and over.
If you have the alternator off, just get another bolt for the new alt.
If you have the alternator off, just get another bolt for the new alt.
Cargo Master
Joined: Jun 2014
Posts: 2,212
Likes: 322
From: Central Florida
Another possibility is that you have an open circuit somewhere in the electrical system. This is easy to check as follows. Remove the negative terminal to the battery then bring it close to the negative battery post. You are looking for a spark. Shade or darkness is helpful b/c the spark could be quite small and hard to see. If you do see a spark, there is an open circuit - a short - somewhere. Look for exposed wires that could be grounding out against metal. That kind of short may be easiest to find. Other open/short circuits may require more sophisticated investigations.
See if you can eliminate this as a suspect.
See if you can eliminate this as a suspect.
Post Fiend
Joined: Apr 2002
Posts: 19,311
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From: Waterloo, Iowa
Welcome to FTE btw.
Don't guess. Use your voltmeter to determine where the fault lays. This stuff is usually simple to diagnose if you are methodical about it.
Automotive start type batteries btw do not like being discharged, even once, it will reduce their lifespan. A half dozen discharges or less may well ruin it permanently.
Anytime there is a "phantom" discharge or parasitic load, battery is mysteriously going dead etc, it is important to disconnect the battery from the vehicle until the fault is remedied. If it is going dead in a few hours, there is a probably a short circuit burning enough current to even start a fire most likely.
Get the battery on a charger and a slow trickle for a couple days and get it back up to 100%, this is important.
http://www.aa1car.com/library/charging_checks.htm
Don't guess. Use your voltmeter to determine where the fault lays. This stuff is usually simple to diagnose if you are methodical about it.
Automotive start type batteries btw do not like being discharged, even once, it will reduce their lifespan. A half dozen discharges or less may well ruin it permanently.
Anytime there is a "phantom" discharge or parasitic load, battery is mysteriously going dead etc, it is important to disconnect the battery from the vehicle until the fault is remedied. If it is going dead in a few hours, there is a probably a short circuit burning enough current to even start a fire most likely.
Get the battery on a charger and a slow trickle for a couple days and get it back up to 100%, this is important.
http://www.aa1car.com/library/charging_checks.htm
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Cross-Country
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Okay I got the alternator off and replaced along with my spark plug wires. It still ran like crap and then I started to check the spark plugs. I found that one of the spark plugs was completely black and this is what caused it to run like crap. I started it up and it ran amazingly. I still do have a slight drain in the battery from a hot wire that I need to find but this spark plug issue starts another problem. Why would that one spark plug be black and the other ones almost as clean as a whistle?
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Mentioned you replaced the spark plugs a few weeks ago, and it's running poorly, backfiring? Is it fouled with oil? You want to try a compression test, maybe a burnt valve or ring problems with that cylinder.
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Cross-Country
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Yes I did replace the spark plugs a few weeks ago. I did jump it one time and it backfired on me and while it idled it popped, but not anymore. But when I checked the spark plug it didn't seem to be wet with oil. The old spark plugs showed a good mixture of fuel and air and none of them were black, they were all how they were supposed to be.
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Post Fiend
Joined: Apr 2002
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From: Waterloo, Iowa
Backfired through the carburetor? That is never a good thing. Sounds a little like it may have "jumped time" even, check with #1 piston at TDC compression and see where rotor is pointing. By that I mean the timing chain and valve train.
Check for how much slop there is in the chain, when turning crank damper bolt back and forth, observe how quickly the rotor moves back and forth when turning the crank bolt, should almost be immediate. It's easier to turn the motor over with the plugs removed.
Check for how much slop there is in the chain, when turning crank damper bolt back and forth, observe how quickly the rotor moves back and forth when turning the crank bolt, should almost be immediate. It's easier to turn the motor over with the plugs removed.
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Cross-Country
Joined: Mar 2016
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It didn't back fire through the carburetor but out the exhaust more than likely from the fuel that wasn't getting burnt out of the cylinder with the gunked up spark plug. Also before it started to run really crappy it would smell like gas fumes were coming out of the exhaust.
Cargo Master
Joined: Jun 2014
Posts: 2,212
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From: Central Florida
A carbon fouled spark plug (very black but not oily instead of a light beige color as all the other plugs are) plus exhaust backfire may indicate that fuel going to that cylinder isn't being fully and properly burned. A bad spark plug wire would be an easy fix so try to observe the spark going from the end of the wire for that cylinder to the spark plug. Do that by removing the wire and cranking the engine with ignition ON while holding the wire close to the end of the spark plug with an insulated grip. A remote starter switch of a helper will be required for this. You should see a big fat blueish spark that easily jumps a quarter inch gap. If you don't see this spark, replace all of your plug wires on the assumption that they are all the same age and will fail one after the other. Repeat the test after replacing wires if that's what you wind up doing.
If you do see this big fat blueish spark, the problem may be deeper, specifically a stuck lifter or bent pushrod. Let's hope it's the spark plug wire or something upstream of that. Let us know what you find.
If you do see this big fat blueish spark, the problem may be deeper, specifically a stuck lifter or bent pushrod. Let's hope it's the spark plug wire or something upstream of that. Let us know what you find.
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Cross-Country
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Ok I replaced the spark plug wires yesterday and the reason I did this is because one of the wires had a crack/chunk out of it and it went to the spark plug that was black so what I am going to do is switch the spark plugs around and see if turns the other spark plug black.
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Cross-Country
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yes I replaced them all except for the wire going from the coil to the rotator box where the spark plugs meet. I am hoping that this is the issue and from what you described the wires could have been the problem.