85camo

I have a 83 Yota PU SR5 with standard 1985 22R- Carb

Before I replaced alternator it started malfunctioning by not charging until after the motor had been running for a while then after about 5-10 mins with some revving it would kick on . This happened for about a month then it finally stopped all together. So....I replaced alternator and regulator .....same problem except worse now it takes more time and revving to kick on.
I checked my wiring and grounds cleaned them up and the problem still exist !
Any help would be greatly appreciated !

85camo

Also in addition to the malfunction the #3 cyl misfires as checked with a timing light, always #3 after alternator kicks in #3 fires great, engine runs fine .
This happens even after it has been driven , warmed up and is shut off for 10-20 mins

wyoming9

iTrader: (1)

Break out the meter !!

Without some voltage numbers impossible to know what is going on.

If the system voltage is to low it can cause ignition issues

Then the quality of Aftermarket rebuilds who can say.

The harness between the alternator and regulator in good shape ?

Battery good ??

terminals clean and tight not broken ??

85camo

Thanx Wyoming9
Took some readings , battery @ 12.60 after sitting for about a week Battery after start up { alternator is acting up} @12.30 Battery after alternator has kicked in {about a minute after start up and a little revving } @ 14.20-30 Alternator comes on sooner in warm afternoon weather ,cold mornings about 30 -40 degrees takes a lot longer 5-10mins

85camo

Yes the connectors and harness are good , battery new and holds a charge terminals very clean and secure

And yes I'm with you on the aftermarket alternators , switched it out on another 83 and it works fine

Co_94_PU

iTrader: (-1)

You say the alternator works on a different vehicle.

You say everything is clean and tight.

Yet you do not have a properly functioning charging circuit, it should be obvious you have wiring issues so everything isn't "fine/working order"..

You need to measure the voltages, there are details in the manual..

Exciter voltage is what?
​​​​​
Output at alternator is what?

Voltage at first junction in B wire is what?

Voltage on B wire at distribution block..

Voltage on S sense wire at distribution block..

Voltage on S sense wire at alternator..

Voltage at vehicle side of fusible link..

Voltage on battery clamp..

Voltage on battery post..

All are relevant and should be pretty close to each other.

85camo

actually I said..... all was clean and secure at battery , wire harness and connectors from alt to reg were good in response to Wyoming9 inquiries, never said everything is in "fine/working order"
I figured it is a wiring problem of some sort as i did check all the grounds and connectors inspected harness , thought maybe the fact that alternator does come on after a bit and the charging system works fine then might help narrow it down.
Thank You for your input Co 94

Thommo Thompson

earth straps from engine to chassis! allways mesing with me and when they start corroding they can conduct electricicty only when hot.

Thommo Thompson

mind u youd probably have some starting issues with that too.....
maybe just a guess. worth a check though. perhaps jsut stick a jumper lead on the engine and across to the negative an start it up cold and see what happens. see if it improves.

85camo

Thanx Thommo, ive checked and cleaned up ground contact points on ground straps , i'll do a jumper lead test.......see if any change
i guess I'm at a loss because of the nature of problem ie the fact that system does charge and run fine after it has been running and after a little "throttling"
So thanx for the heads up !

85camo

actually the old beast starts right up without fail , at least since i 've owned it

RAD4Runner

85camo,
Toyota components are bullet-proof. Problems often arise from or wiring, maintenance, etc. See signature.

What do you mean by this? What is your indication? The stock gauge is not exact; it may even be broken. Best to monitor actual voltage with a digital read-out/ multi-meter.

HOW CHARGING SYSTEM WORKS IS HERE.
It is for 22RE alt with built-in regulator but concept and test voltages should be the same.
"Exciter" that Co says above is "IG"
"S", and output "B" are the same.
"B" voltage on healthy charging system should range from 13.5 to 15.1V depending on state of battery and temperature.
"S", "IG" and "B" Voltages measured at stud terminal of alternator, at fuse block, and other points should be very close to each other (my rule of thumb is voltage drop < 3%). Too much difference means wiring problem between those points.

85camo

Thanx Rad,
what I mean by" kicking on "after 5-10 mins and a little revving..... is that when first starting truck the motor fires up ...every time. But it is misfiring, rough idle and stock SR5 altmeter in truck shows no charge actually a discharge below the 12V mark, while its running badly i checked voltage with my multimeter reads it @ 12.20-30 ish
After about a minute of running on "warm afternoons" , with a little revving of motor the alternator comes on and motor runs fine stock gauge reads around the 14V mark , multimeter reads @14.20-30
The difference is on cold mornings it takes about 5-10 mins to come on.
After alternator comes on and charging system is working fine it stays that way while I drive it ..... until I stop and turn motor off and it sits for a bit, then the whole thing happens again

85camo

To be clear ,,,,after i see the stock gauge needle move over to around the 14plus mark the motor runs fine ...no missing , idles good and the multimeter reads good..... I am sure the alternator has come on,I've checked it at the battery multimeter reads @14.20-30
Ive not had a dead or low battery in this truck
All lighting, horn, turn signals, flashers, heater, wipers everything electric seems to work fine never had a problem with any of it until this

RAD4Runner

Cool...
Might be a chicken or the egg thing...
Could it be that alternator is not producing proper voltage because of the miss and the low rpm, or the miss because of the low voltage?

85camo

Well said Rad ! I don't know, I did a number of swaps with distributor , IGs, plug wires, new cap & rotor from running Trucks ....no change so I don't know ???
As I said earlier it's always #3 cyl , watching timing light, as soon as "alternator comes on #3 is firing normally
The funny thing is that when the motor is running badly my multimeter says its charging @ 12.20-30 V at battery. That's not to much of a drop in voltage as if it were around 11V or lower ???

NYHumpinUtah

iTrader: (1)

This might be a stupid idea but have you checked the spark plug wire on #3? I am in no way good at electrical but there has to be some correlation between your problem and #3 misfiring

NYHumpinUtah

iTrader: (1)

Another thing
Wait till it;s pitch black dark outside, pop the hood, start the engine and while doing some revs look for any spark arcs everywhere............

Co_94_PU

iTrader: (-1)

More likely a spread plug gap than a leak in the high tension line (sparkplug wire). Think of it like this the higher the gap the more energy required to make a bridge across open air. So if the wire was leaking power it would continue to do so (if not get worse) with higher voltage to the coil. However if the spark gap is excessively large it's going to take exponentially larger voltage to bridge the gap. So at the lower twelve volt supply you have a weak spark because the plug needs regapped, this happens due to usage wear on the electrode.

The OP likely has a dirty connection, loose or failed wire on the IG (provides exciter power). This could be a flakey fuse, bad wire (fraying wire strands), or a loose dirty connection (makes contact when up to operating temp but has some corrosion preventing it while cold)

Thommo Thompson

yes likely to be spark plug 3 is gapped bigger or worn out.
I am adamant (form expereince) that low voltage will become evident with a missfire on the worst spark plug before the others, this is because the energy gets stored better because that one failing cylinder doesnt sap the coil of its charge time (capacity) and the others fire better, so a tiny difference makes the worst one fail first, every time.
In my epxerience the HT cable can be an issue, but it is just so unlikely compared to a simple plug gap being bigger.

Heat does make wires miraculously start conducting electricity when they didnt at colder teps, and usually in the lower current connections, like the refference wire to the alternator which tells it the system voltage for the internal regulator to do its thing. on some this is just a connection in the alternator to the battery charge wire, but most have a seperate wire. cehck the plug and clean it out.