82FanTC

iTrader: (9)

Recap: Poor idle, poor top end, bucking and shuttering while cruising, choke won't stay out; all of these problems came on suddenly...

Today I did lots of trouble shooting. Checked fuel at the pump which was good. Replaced the fuel filter. Checked the spark plugs which were good. Put a T in fuel line before the carb and poured seafoam in to clean the carb. Checked all vacuum lines that I could see.... All seemed to be ok.

Then went for a drive and the car was still driving horribly with all the same symptoms... then dash lights got dim, headlights got dim, noticed amps way down at just above 8! Car dies and had to push start b/c the batt was almost dead.

Is my alternator dead... could that cause all these problems???

Rx-7Doctor

iTrader: (13)

Well it means the charging system is not operating properly. Need to take off the alternator and have it tested.
When you voltage starts getting low then there is not enough voltage to the fuel pump. The lower the voltage the less output it will put out.

82FanTC

iTrader: (9)

If the alternator is dead... and I have a brand new battery, would there be immediate problems such as mine b/c of reduced spark from the ignition, or would the battery produce enough spark before I noticed my lights dying?

It seemed like a fuel problem before my charging system failed but now things are multiplying

Rx-7Doctor

iTrader: (13)

If you have a fully charged battery you could drive the vehicle for awhile without a functional charging system, especially if you are not doing any night driving.

The battery does not provide spark it supplies voltage to the electrical components such as the ignitor and coil that provide spark.

The battery can fall to about 9.6 volts before things should start to go downhill.

82FanTC

iTrader: (9)

Right, I realize that the batt provides voltage to the coils and ignitor.

But pretty much there would be no immediate problem to electrical system (ie spark) or the fuel pump b/c there would still be enough juice in the battery to power everything.

So even if my alternator is dead... I still have an underlying problem. Because I mean my car literally went from running perfectly to running terribly!

So I was hoping you would say that a blown alternator could cause poor running immidiately... but that seems to not be the case, right???


Thanks

Rx-7Doctor

iTrader: (13)

I am going to guess that after you put in the new battery the voltage gauge was reading around the 12volt range for while.
If you have a problem with a ground such as the alternator arm being painted or just highly corrroded ground connections then you will still have problems even with a new battery.

82FanTC

iTrader: (9)

Sorry for all the recapping but I want to be clear:

Old battery froze over winter in storage, got new one. Car drove great. Have only driven about 150 miles. Out for a cruise over the weekend and car went bonkers in middle of the drive, IMMEDIATELY. Bad idle, no power in high RPMs, bucks and shutters at cruising speeds.

Then battery went dead today (Maybe 25-50 miles after the onset of problems). So I know I need to look into the charging problem, but could this be related to the rest of the problems??

Thanks

twinkletoes

iTrader: (17)

Your problem used to be similar to mine about the shuttering and bucking and poor running. It could be abad shutter valve. Take off the air cleaner lid and listen for a loud honking noise, plug the hole that goes to the shutter valve hose closet to the drivers seat. IFthe plugging stops or it runs better, keep it plugged. This "shutter valve" isnt really nessecary. It won't hurt anything plugging it too if its the problem.

rotor rod

Do you have a volt meter? If so, put that baby on the battery and see what you are getting, you should see between 13.8 to 14.2 volts @ the battery if the alternator is doing it's job.
Could also be poor connection like rx7 doctor said.

Sounds like a charging problem, with the symptoms you provided I would start there.

It doesn't take long to juice a battery if the alt is not charging it. Did you drive it right after you put the new batt in it?

82FanTC

iTrader: (9)

Do I pull my alternator off and bring it in to get tested or do I need to bring in the car?

Rx-7Doctor

iTrader: (13)

Check your thread for this answer. :-)

vipernicus42

iTrader: (4)

I don't know about where you are, but here the local Canadian Tire or PartSource will test alternators for free if you bring just the alt in... but charge you an hour's labour if you bring the car with the alternator still installed.

Jon

Ovid213

'82 still has an external voltage regulator, right?

Rx-7Doctor

iTrader: (13)

No.

twinkletoes

iTrader: (17)

You can have the alternator tested on the car

Rx-7Doctor

iTrader: (13)

^ That is true. However you want to isolate the systems so that you can pinpoint the actual problem. If the alternator is tested off of the vehicle and tests good then there is a problem in the electrical portion on the vehicle.

82FanTC

iTrader: (9)

Well Doc, the alternator tested good. I am begining to think I am in over my head here. I checked the grounds as well as I could and they seemed solid. I have never had anything painted and there isn't any corrosion on the car anywhere.

Any ideas of where to check next??? Guy at the car shop said that my alternator could stop making power after it heats up so if I could get my car to idle I could put a volt meter on my battery, unfortunately I don't think I can.

Anyone know a good mechanic in Minneapolis??

Rx-7Doctor

iTrader: (13)

The stop charging after it gets hot I would go for if it was a American alternator. That is a common thing for those but not our type of alternators.

Are you saying that your engine will not idle at all?

You need to have someone keep the engine running while you check for voltage output at the back of the alternator. Also inspect the wiring to the alternator. It is only 2 wires so it should be easy to see if maybe a rat or something chewed thru the wiring.

If I am reading the wiring diagram correctly the circuit is protected by a 15 amp fuse. I don't have any fuse box illustrations. Is there a 15 amp fuse in the fuse box that is blown?
Also there looks like the main power wire to the alternator has a fuseable link off of the main large wire. Does that wire tie into the fuseable link holder? And if so is one of those links bad?

74RX4

iTrader: (10)

Make sure the terminals on the fusible link box are clean. I've had crude on the terminals stop more than one car.

gene_fitz

Sometime else you may want to check. If you alternator is running okay, check your battery cables, not just at the battery. Funny story, I troubleshot for 6 hours on a charging problem, only to find that the root cause was a loose cable on my starter. I know it sounds odd, but many times, it is the simplest thing..

Also, you may want to check your fuel pump, it may have a short. A lot of times it will cause speratic work.
Look, vibration is hell on electrical, and sometimes we vibrate and shake..