wont idle and amp meter is pegging

[fj404life]

Was" wont idle and amp meter is pegging" now who knows LOL

Hey all! Took my stock 69 for a lil drive today. On the way back I decided to test out my new brakes. Slammed em on and they work great! But my motor died.

Started it back up and it would not idle and the amp meter would peg the + side with any rpms.
Motor sounds and runs fine as long as I keep the rpms up.
Stalled it again. Then I started it up and it was fine till I got home then died again as I pulled in the drive.

Brought it in the shop and messed with stuff for a while.
Tried to start again and it ran fine, idled, and the amp meter was acting normal. Shut it off, cleaned up some tools. Went to take it for a spin to see if I had actually somehow fixed the problem. Started acting up again. Same deal wont idle, and the amp meter is either pegged when some throttle is applied or drops to the negatives when you let off the gas. Motor dies if you let off completely.

My neighbor and I think its the regulator but thought I would run my symptoms by the pros.

I though maybe something was shorting out....would sort of explain the problem starting after my
'brake test".
But having the problem go away and come back just sitting there in the shop leads me other directions.

What ya thinking before I start ordering parts?????

 

[Pin_Head]

Wierd stuff, but it seems all related to the quick stop. Cheeck for a bad engine to frame ground as that is the only thing that might connect the alternator output and the idling.

 

[fj404life]

Checked all the wiring out. Battery didnt budge.
I just put all new tune up parts in a few weeks ago. Points, condensor, cap, rotor, wires, plugs. (has been running great ever since)
I was out messing with it some more. It is totally random.
One time you start it and all is well. Next time it wont want to idle, amp meter will be in the neg unless I give it some gas then it pegs +.
I had it working ok about 50% of the time as I ran it up to temp in the shop.
I checked the voltage at the batt and it is ok seems average about 13.5-14.5 depending on throttle applied.
Gave everything I could a wiggle while it was running no change.
Can a voltage reg going out cause my rig to not idle/charge and peg the meter when any throttle is applied?
Also I see SOR list an aftermarket reg and a reconditioned oem reg. Which one do I want to get?
Are new OEM available?

 

[Pin_Head]

Checked all the wiring out. Battery didnt budge.
I just put all new tune up parts in a few weeks ago. Points, condensor, cap, rotor, wires, plugs.
I was out messing with it some more. It is totally random.
One time you start it and all is well. Next time it wont want to idle, amp meter will be in the neg unless I give it some gas then it pegs +.
I had it working ok about 50% of the time as I ran it up to temp in the shop.
I checked the voltage at the batt and it is ok seems average about 13.5-14.5 depending on throttle applied.
Gave everything I could a wiggle while it was running no change.
Can a voltage reg going out cause my rig to not idle/charge and peg the meter when any throttle is applied?
Also I see SOR list an aftermarket reg and a reconditioned oem reg. Which one do I want to get?
Are new OEM available?

None of that sounds particularly relevant.

How about your engine to frame strap?

Is your idle fuel cut off solenoid (not selenoid or silenoid) working? Is the alternator ground wire (white with black stripe) hot?


No, not idling is not something that a bad VR would do.

 

[fj404life]

My carb does not have a sillynoid. I got the odd year (month) on the carb I think.
I looked everywhere for a ground strap on the engine...could not find one anywhere?

 

[lostmarbles]

I back your suspicion that the hard braking caused an intermittent wiring short-circuit to develop.

You obviously know what you're doing --- so I reckon you should just keep on trying to track it down.

I doubt it would be the voltage regulator unless its internals have come loose (which is possible).

Intermittent faults are almost always very difficult to locate.

Since the motor died - perhaps you should concentrate on wiring/items that are supplied from the same fuse (or fusible-link) as your ignition. (I'm not familiar with non-diesel wiring and don't wish to learn about it.) I'm guessing that the short-circuit produced sufficient voltage-drop to stop your spark without being sufficient to blow a fuse (or fusible link).

 

[inkpot]

Howdy! Could be a loose/bare wire grounding out due to movements. John

 

[fj404life]

I really don't know if the hard braking caused it or if it just is a coincidence...
Thinking back to my drive it did stumble once on me when I was goofing around in some snow and almost died. I didn't look at the amp meter at the time. But its so random even sitting in the shop with no bumping around driving.

 

[KOOTENAY KRUZER]

All I can suggest is start it up then start wiggling wires under the hood and behind the dash, see if you can make the problem appear. Intermittent electrical problems suck big time!

 

[fj404life]

Checked all wires on alternator with motor not running the only hot wire was the big one that goes to the stud.
Also pulled the neg lead on batt and checked for draw/short. No spark at all when tapping the lead on the batt post.

 

[Pin_Head]

I looked everywhere for a ground strap on the engine...could not find one anywhere?

You need a ground strap. It goes from one of the starter motor mounting bolts to the frame.

Is your alternator ground wire burned up or shows evedence of melting or heating?

 

[fj404life]

As in I should add a groundstrap? This thing is about as virgin as a 69 can get as far as the wiring etc.
The pos cable from batt goes to starter...then the neg is grounded straight to the frame up front. The only other ground I
have come across so far is out of the harness to the taillights on the frame.
All is in good shape though. Nothing I have come across looks charred chaffed or otherwise messed up.

The random amp meter working then it wanting to spike full max with any throttle out of the blue has to to mean something.
What can cause that spike that would kill the motor at idle only?

 

[terrx]

If you have a voltmeter, hook it up to the battery and see what the voltage is when he amp meter is acting strange, e.g. idle vs. high rpms. Would be interesting to know what voltage it's seeing from the alternator when this is happening. Did the shop test the alt at idle as well as high rpms?

 

[Pin_Head]

It is also quite possible that the symptoms are unrelated.

Wait and see if the battery chages and the amp meter falls back into normal operation. If you you might consider replacing the voltage regulator.

Tune it up and adjust the idle mixture and speed. It should be able to idle if you adjust it.

 

[fj404life]

I did try to catch it acting funny with a voltmeter. I never got any really high/low readings though.
They did jump around 13-14.5....but I am guessing that is normal for a mech regulator?
I didnt take it to a shop....I took it to my shop.
I dont give up that easy heheh. I will mess with it some more today.
I got a new regulator from napa to try out. Figured it would be a good spare if thats not the problem.
I pulled the original and it was very corroded and full of rust flakes when I popped the cover.

 

[fj404life]

Ok I grabbed a new regulator at Napa this morning. Swapped it in and fired it up.
Seemed to be ok. Though I am now getting 15.5-16volts at highway rpm.
Took it for a quick spin down my road and back. Shut it off, started it up and it didnt want to idle.
If I let the RPMs drop off the amp meter goes down into the negative, about the same area it is at when you just turn the key to run. Blip the throttle and the meter pegs. Hold throttle and needle pegs then bumps down a little bit from pegged+ after a few seconds. Second I let off the gas...motor wants to die and amps drop to neg.

 

[4x4 Station Wagon]

What can cause that spike that would kill the motor at idle only?

What do you think about unhooking the wire to the altenator and then just letting it run on its own juice to verify that the altenator for some reason isnt shorting out in itself or ?? and causing it to pull very hard..... It just reminds me of when you try to back your idle down and all is good at idle until you kick your Air conditioner on and then it pulls your idle down and dies..... I know it is probably a But your probably getting closer to trying anything at this point

 

[fj404life]

Which wire? The big one to the lug or the 2 small ones that plug in?
And where in Oregon are ya?

 

[4x4 Station Wagon]

I found this stuff on another post on mud it is worth checking:

Since you have been having electrical problems too, check the "engine" fuse and then check the idle fuel solenoid on the carb. If there is no power to the solenoid or if the solenoid isn't working it will run fine at high speed, but die at idle, like you described.

He later replies with

Thanks guys, I will check all of these things tonight.

I forgot to mention- the ammeter is MAXXED OUT when the truck is running-it didn't used to do this.

Also, the exhaust is blowing black smoke-is this from running choked?

Some more info:

Had a similar issue on my FJ60. Check the engine or charge fuse. I blew one or the other (can't remember which) and the alternator shot to full charge. Battery was boiling in less than a mile (fresh 90 amp Delco alternator). Headlights were nice and bright though.

Something is telling the voltage regulator to push full charge out of the alternator. Might be as simple as recharging the battery with a battery charger instead of cooking the alternator. Or the regulator needs to be taken apart and the contacts cleaned. Or one of the wires to the regulator is broken and the regulator thinks there is no voltage and is calling for full charge from the alternator.

Here is the link if it helps at all..... It was an old post and they didnt post if they ever got it fixed but the last thing they did talk about was possible vacuum leaks specifically the PCV valve on top of the valve cover....

https://forum.ih8mud.com/40-55-series-tech/103651-what-now-more-fj40-problems.html

 

[4x4 Station Wagon]

Riddle, Oregon! Or how about Canyonville where the big Indian Gaming Casino is near exit 99 on I-5.

Good question on the wires because if the altenator is shorting ?? How about the two small wires hopefully preventing it from kicking on??