wont idle and amp meter is pegging

[fj404life]

Ok well I have gotten somewhere...and I have gotten nowhere.
I put the new alternator on. Fired it up and it still did not want to idle.
So I did the old carb trick where you raise the rpms up and then slam your hand down on top of the carb choking the intake out which sucks hard vac and hopefully clears out your idle circut.
Anyways after doing this a couple times my rig would not run at all hardly.
Pulled a plug and it was soaked. Tossed some new plugs in and it fired back up but was running rough.
Did the carb trick a couple more times at higher rpm and after clearing out and a couple blips its purring better than ever.

BUT! My amp meter is still acting funny! At idle with nothing running it is bouncing between neg and pos. And with a blast of throttle its pegging out still. It will eventually settle down.
Also my new regulator seems to be pumping out to much voltage.
I am going to pull it and check out the specs. I know you can adjust them but not sure what I need to tweak?

Also this is the odd ball 69 carb that was only used for a few months I believe. Is there a rebuild kit available for this carb still?

 

[bsmith123]

checks

might not be a bad idea to look for those loose wires or bad connections ---I'm not convinced but still could be

also might want to shoot the wires for shorts instead of just continuity remember shorts can be wire to wire as well as to ground

shame the alternator didnt do the trick---

 

[lostmarbles]

This is a long-shot. (And if I was you I'd only consider trying it if you have a spare battery lying around that you can easily swap in.)

But I'm thinking maybe your battery has some sort of internal fault that is causing it to lose almost all its voltage periodically.

I'm suggesting this because I had a wierd fault with a battery once when we were all going away on holiday. The battery was about 5 years old and I had only just perfomed a "load test" on it which it had passed with flying colours. Anyway - When we stopped to buy icecreams after about 200kms driving - my engine wouldn't restart. (The only time in 30 years that my vehicle has let me down too!) So I pulled out my voltmenter (which I always carry) and was astounded to find absolutely NO voltage at the battery terminals. (The internals of the battery must have collapsed from the road vibrations!)

So you can perhaps now understand why I'm suggesting you try a different battery. (Perhaps your sudden-braking has broken some lead-connections/plates inside your battery and this is maybe the cause of your problem.)

......... I don't blame you if you're sceptical though - but I thought I'd suggest it anyway.

Cheers

PS. After that experience of mine I no longer buy "economy-class batteries" and I automatically dump my batteries after 5 years service even if they still check out perfectly.

PPPS. I think this fault, provided it is intermittent, could possibly cause all your symptoms. (The "voltmeter pegging", the "engine-dying", and the "high charging voltage".)

 

[fj404life]

Interesting thought!
I checked out the wiring at the back of the amp meter tonight. Looks great to me. All tight and clean and no signs of anything getting hot.
Ill toss another battery in tomorrow for giggles...thats easy enough!
I hear ya on the cheapo batteries! There is a LOT of crap floating around out there these days!

 

[fj404life]

Ok guys...just wanted to update where Im at.
I got the truck to idle and the amp meter seems to be working proper.
Here is the latest issue that has sprung up.

After driving long enough to get truck up to temp, when I go to restart the motor the starter turns over VERY slow. Also when this occurs the amp meter does not drop the normal amount when the key is turned to the run position like the coil is not drawing as much power as usual.
Let truck cool off and start it up and all acts normal. Starter turns nice and fast, and the amp meter drops the usual (3/16"ish from neutral)when you turn the key to run.
So...something is getting hot (coil????) and when I try to start it is sucking the voltage down to where the starter barely turns. or??? Whachya think????

 

[psreno]

Could something be shorting out on the starter?

They have heat shield blankets for starters. But with the ammeter bouncing I'm wondering if the short is internal?
You can rebuild the solenoid relatively easily, so I'm told.

 

[fj404life]

here is an email I just sent to my mechanic buddy. It describes my symptoms a lil better.
I am starting to get this sorted out. I think I have been chasing a couple problems this whole time.
Now I think I have it narrowed down to something acting up when its hot.

What I have done:

New Battery
New Alternator
Tried new and am currently back to old regulator (due to new one overcharging battery)
Cleaned up ground and connections to starter (didn't really need it)
Checked all wiring between the alt/amp meter/starter
Tried running a jumper cable from battery negative to starter housing to rule out bad motor/starter ground as there is no ground strap off the starter/motor (no change)

Current symptoms:

When cold truck starts and runs awesome. Amp meter is acting normal. Runs just above neutral when running.
Meter drops the normal 3/16" or so when you turn the key to run and the coil is energized (motor off).
Drive truck long enough for it to get up to temp fully. Turn off and try to start, and starter turns very slowly if at all and battery voltage gets sucked down hard to around 9volts. Also when warm if you click the key to run the amp meter will very slowly move down to the negatives just a tiny bit.

I sort of ruled out the ignition switch. When the truck is cool I can flip that switch back and forth a ton of times and always get the same drop on the amp meter in run, and it always starts good and fast.

Let truck sit and cool a short while and all is back to normal.
Coil is quite warm (not quite hot) to the touch after driving. Starter is cool.
Both starter and coil are original as far as I know (they look it).

 

[lostmarbles]

Baffling!

I take it that your new battery is big enough and fully charged? (Mine is 700 CCA but then my cruiser is a diesel so I need more CCA than you.)

I have an old battery tester that I use to see how well my battery keeps its voltage during a big current drawn-off:



Perhaps if there is any doubt as to your battery charge (and if you haven't got something to adequately test your battery performance with) - charge it for 24 hours and see if your vehicle maintains the same symptoms.

I know - Sounds like I've got a one-track mind in continuing to suspect your battery..... but I find it hard to think of an alternative reason.



(PS. After a vehicle has been running there tends to be more oil on the cylinder walls which tends to provide higher compression...... - This is my reasoning for your variation between hot and cold starting performance anyway.)

 

[fj404life]

Battery is a couple months old sears diehard out of my daily driver gmc truck and I put it on the tender last night just to make sure it was totally topped up.

 

[Pin_Head]

It still isn't that clear what the problem is:

Is the battery run down (discharged) or the starter motor just won't turn when it is hot? Did you try jumping between the starter ground and the battery ground when it wouldn't start?

Did you make sure that the VR has a good ground by running a jumper? Is the white black stripe ground wire attached to the VR case?

What is the alternator voltage when the amp meter is pegged?

Odd ball possibilities: If the VR has a good ground, then maybe the amp meter has a bad shunt. It might be corroded or have a lose connection so more current than normal is flowing through the meter. In other words, it isn't over charging, the meter is reading too high.

 

[fj404life]

Starter turns super slow when engine is hot.
I did run a jumper cable to the starter from batt ground no change.
Yes I ran a jumper ground like you said from the regulator. Ther is also the original blk/wh wire attached from alt.
Alternator voltage is fine now with my original regulator installed...was high and pegging with new napa regulator.

Everything acts perfect when the truck is cool. Drive it up to temp, turn it off and try to start it and the starter turns very slow. Also when this is occuring the amp meter does not drop off the normal amount when you just turn the key to run (only coil is energized). It just slowly drops a tiny amount. When truck is cool and working good it drops a lot more when you turn the key to run and lot quicker (which is how it was before all this started).

 

[bsmith123]

another idea

I think your ignition is fine since it runs good once started and since your alt and batt feed into that if they were messing up it seems you would see other symptoms


When hot if your starter bearings are worn the armature can touch the case and short out.

This whole thing has seemed to be related to a short IMHO, but you may be better off for the time being because all the new parts--alt, batt, etc so its running ok. I have seen badly worn starters work okay with jump starts if you know what I mean.

try running a wire from your batt to your coil and pull the start and run wire off your coil. the coil will be hot (have voltage) all the time but this is just for testing.if the prob goes away it you know it is in the start/ignition sw circuit wiring

if not try bumping the truck forward a little and see if it starts normally---seeing if it is on a "bad" spot. If so the starter is worn out ---replace it

If you know how you could ohm out the starter and solenoid and look for shorts and high resistance/opens

it would be best to do this hot when you are having the prob obviously


Well food for thought anyway--let us know what you find

 

[Pin_Head]

It could be a bad starter or solenoid. Try rapping on it with a hammer to see if it takes off and starts.

 

[fj404life]

When the engine is hot (starter still feels cold to touch) and the starter turns slow. I can keep trying it and it will only spin slow till I let it sit and cool down a bit (rules out dead spot?). What is confusing me and why I have not just ordered up a new gear reduction starter for it is the amp meter dropping a different amount (when key is in run position) when its warm vs cold. There is no power going to the solenoid in the run position, only start. So the coil has got to be what is causing the difference or am I missing something here.

On another note (or the same)I need to see if I can get an oem voltage regulator or something. The POS from napa was putting out 16v at the batt. Tried setting gaps and could not get it down to a happy level so I put the old one back on...which who knows...I cleaned it up, and I have good voltage at the batt now 13-14.5 depending on throttle.

 

[lostmarbles]

...... starter turns very slowly if at all and battery voltage gets sucked down hard to around 9volts. ......

You'll see that a "9V" reading on my antique battery tester indicates "recharge and try again".

And to drop your "new" battery's voltage down to 9V should require a VERY high current draw-off - assuming this battery is indeed "good".

And a big current drawoff means either "a big power output from you starter" or "a lot of heat build-up and arcing somewhere".

Yet you say your starter doesn't get hot , and it can't crank your motor (when your motor is hot).

So I now think your second battery isn't up to scratch!

He he he (I'm deadly serious though.)

 

[fj404life]

Ya I know (about the 9v thing)...but when the truck is cool. That battery doesnt drop below 12v.
And it came out of my daily drive full size gmc truck. I can go out there right now with a cold truck and start it 50 times I bet easy. Go drive it till *something* gets warm and it starts acting up.
Im not familiar with modes of failure for starters and coils. Always heard coils either work or dont. And any starter that has gone out on me has just quit working.
And the whole bad starter thing doesnt explain my amp meter symptoms I dont think?

So ya all I can really do is guess. HAH

 

[lostmarbles]

Ya I know (about the 9v thing)...but when the truck is cool. That battery doesnt drop below 12v.
And it came out of my daily drive full size gmc truck. I can go out there right now with a cold truck and start it 50 times I bet easy. Go drive it till *something* gets warm and it starts acting up.
Im not familiar with modes of failure for starters and coils. Always heard coils either work or dont. And any starter that has gone out on me has just quit working.
And the whole bad starter thing doesnt explain my amp meter symptoms I dont think?

So ya all I can really do is guess. HAH

I used to think that a smaller engine would automatically have a smaller starter motor (kW) but you only need to look at minitrucks to see that the opposite is often true.

Perhaps your FJ starter puts a higher demand on your battery than your GMC starter? (Especially when your FJ engine is hot.)

I can't get away from the idea that hot-starts may require more starter power than cold starts (due to the improved compression from oil being on the cylinder walls) .

And during your hot-start attempts your "new" battery's voltage dwindles away to what I consider to be an unacceptably low value - (9V).


.

PS. What cured the "stalling when idling" problem or aren't you sure?

 

[bsmith123]

Cranking

"it is the amp meter dropping a different amount (when key is in run position) when its warm vs cold. There is no power going to the solenoid in the run position, only start. So the coil has got to be what is causing the difference or am I missing something here."

"Ya I know (about the 9v thing)...but when the truck is cool. That battery doesnt drop below 12v."

It is normal to have the voltage drop while cranking below about 10 volts though and you will have trouble. One thing not mentioned yet is timing. I dont think that but kickback can occur

anyway the articles will tell you how to do the tests you need to do and the typing is already done!



Read This

Slow Cranking Starter

and this
Cranking Voltage Test

and this

To test your battery use you muti-meter and set to DC volts, Check voltage across the battery terminals and look for around 12.5 volts, as you turn ignition on it will drop maybe to around 11.5 and as you turn the starter it will drop again to around 10 volts. When the engine starts you will see voltage rise to around 14.5. See photo below
http://www.hillsidegarage.f9.co.uk/good_battery.gif
Ideally you would check the current draw of the starter motor to test it's performance (assuming the engine is in good condition and turns over freely)

To test your live lead to the starter, check the voltage between the live battery terminal and the starter live terminal, this should be zero until you operate the starter and then it should be no more than half a volt.

To test your earth lead, check the voltage between the battery earth terminal and a good clean contact on the engine, again this will be zero until you operate the starter and then it should be no more than half a volt.

To test your alternator and the live and earth leads - Use your multi-meter and set to DC volts,

1) Check voltage across battery posts with engine running at about 1500 rpm, with heater fan, heated rear window and headlights on. It should be 13.6 to 14.4 volts.

2) Same conditions but check voltage between battery positive terminal and alternator main output terminal bolt which is usually the large one. This should be less than 500mv.

3) Same conditions again and check the voltage between the alternator's metal casing and the battery negative post. This should be 250mv max.

4) Switch to AC volts and check across the battery for any AC voltage. This should be virtually zero
and this

Forget the jumper ground clean the ground connections shoot the cable for resistance and hook it back up---dont take the easy way ---Do this


If the wiring all checks out then here's your trouble:

 

[fj404life]

Battery is the best sears diehard they make.

Not sure what cured my not idleing problem. Was either the old school slap your hand on the carb at high rpm or the batt/alternator swap.
Also how could the above explain the smaller drop on the amp meter in the run position when motor is warm?
BSmith I am printing that up!

 

[Buckwheat]

Starter going south

Put a starter in it. A dragging starter when engine is hot, a common failure, is because the armature is hitting the case, either because it is swollen or getting out of round as the insulation breaks down. The bad bearings thing as above makes sense, too. That's why PinHead said beat on it - it can jar the armature loose to where it will spin. Do a starter draw test with a meter other than the dash gauge.