Idle issues (2 Viewers)

[Keith87VT]

So, I bought an fj60, when we bought it it wouldn't idle at all. after some research I found that this was related to a vacuum issue in the airpump. after resolving that it ran great(in ayard and on a short drive, however after about 1hr of wheelin, the issue came back, and had an added symptom. I now am losing charge. So my question is, would an issue with charge and alternator cause an issue with idle? I imagine that it could but just looking for some confirmation that I should pursue that

 

[Keith87VT]

its an 83 and still has all the smog stuff and stock everything motor

 

[Slow Left]

... I found that this was related to a vacuum issue in the airpump....

...I now am losing charge....

So what was the issue with the airpump and how did you resolve/fix that issue?

Does loosing charge mean that the battery is dying when it sits a long time? How long does it have to sit before you notice an effect? Are you measuring a loss of voltage in the battery, or just noticing that the gauge inside the vehicle is below 12V...?

 

[BlueCruiser84]

Yes, clarify losing charge. If it is a very low idle then the alternator may not be spinning fast enough to output its full 14.3 volts. Does the volt gauge go up when you use the throttle to raise the idle?

 

[Keith87VT]

Volt meter goes down. I started the day at 12v on a new battery as I drove it seemed to stay between 10-12v. After bout 1.5 hr I turned the truck off to help clear a trail of some logs and when I restarted it the problem began. It was reading 8v and wouldn't idle. When flooring the pedal it doesn't go up it actually seems to drain more. I was measuring this with the dash gauge.

 

[Slow Left]

If you have a new battery installed and as you run the engine, the battery is draining, then the alternator is not charging the battery (so the engine is running off of the battery).

I can think of two possible reasons why the alternator is not charging the battery:
1) the alternator itself is not working properly
2) the belt that drives the alternator is 'slipping'

The Factory Service Manual has instructions for testing the alternator. Or you can try calling a local Aftermarket Autoparts Store and see if they do free alternator/battery testing.

The FSM also shows how to check and adjust the tension on the belt that drives the alternator.

The only relationship that I can think of between the symptoms above that you attribute to vac related and alternator related, is that the same belt drives the Air Pump that drives the Alternator.
If a component, in this case the Air Pump, is seizing up or has seized up (it has happened to me), then when it seizes, the crank pulley will still try to pull the belt around that seized pulley on the Air Pump and the belt will get hot. If the belt is really tight, the seized pulley on the Air Pump can prevent the crank from rotating, so the engine will die...

 

[Slow Left]

Still not clear on what you diagnosis was on what was wrong with the Air Pump, how that relates to vac leak and what you did to fix it.

 

[gregnash]

Long shot, but possibly the vane pump was spinning freely with the vacuum leak previously. Now that the vacuum leak has been corrected it is spinning with more parasitic drag which has either fried the alternator/voltage regulator or is slowly killing it.

First I would take the ALT/VR off along with the battery and take all three to your local parts store and have them bench test all three to see if that reveals anything. If not, then take home and reinstall and drive the truck to the same LPS and have them test while the truck is running (normal test). This should reveal something.

 

[Slow Left]

It's unclear to me (unless the OP can explain it) how the Air Injection (AI) System could lead to a vac leak.

The AI injects either fresh air (from the Smog Pump, aka Air Pump, aka Vane Pump (VP)) into the exhaust manifold through the air rail manifold (17351) or sends the fresh air down the Down Pipe.

When air from the Air Pump is passed through the Air Bypass Valve/Air Switching Valve Assembly (ABV/ASV - 25710) and into the Air Rail, it mixes with the exhaust in the exhaust manifold and some of this air/exhaust mixture finds its way back into the cylinder chambers through the EGR system if the EGR valve is open.
When the air from the Air Pump is diverted, it is sent down (I think) the the Tube 17361 and out into the exhaust through that skinny exhaust pipe that mates with the exhaust downpipe.

On both the Air Rail and the Exhaust Downpipe there are check valves (red arrows) that allow the flow of gas only one direction, in each case allowing the fresh air to flow out away from the ABV/ASV assembly and into either the Air Rail or the Down Pipe...and preventing the flow of exhaust back into the ABV/ASV system.

So, there is no vac associate with the AI system. There is vac related to the EGR system, but I can't see how fixing something in the AI system would fix a leak in the EGR system...

 

[Keith87VT]

Sorry for being vague and confusing. The initial issue was that there was a hose to air pump that had come off, so I had no vacuum. As the truck was new to me I had no idea a hose was supposed to be in the empty spot but after looking on here I found the answer to the problem. The new issue I don't believe to be vacuum related (hope not anyway). My thought is that with it only pushing 8 amps, the idle control on the carb isn't opening right. That is my guess, but I'm hoping that one of you has seen this cause my kind of issue in the past.

 

[Slow Left]

The initial issue was that there was a hose to air pump that had come off, so I had no vacuum.

So just to clarify, the AI system is not related to vacuum. The only thing the AI does is move fresh air (that is being pumped by the Air Pump) either into the exhaust manifold to be mixed or (as controlled by the ABV/ASV) down into the Down Pipe to go out with the exhaust.

Vacuum (the vac that is related to the idle/performance of the engine) is created in the throat of the carb.

So while it is unlikely that a missing hose on the Air Pump will cause a vac leak, it will just mean that fresh air in the AI system won't go where it's supposed to go. Bad check valves (if a check valve is bad, it will allow gases to flow both ways across it's diaphragm), on the other hand are a source for exhaust leaks, which might lead to a loss of power.

 

[Slow Left]

...the idle control on the carb isn't opening right. That is my guess, but I'm hoping that one of you has seen this cause my kind of issue in the past.

This is likely. If you do a search on MUD for instructions on how to diagnose and fix the ICS (Idle Control Solenoid), then ruling that out as a cause for a bad idle is a good next step.

Short version of testing the ICS:
1) Engine off
2) Unplug the green connector of the ICS at the carb
3) Turn ignition to 'On' but not 'Start'
4) Reconnect the green connector on the ICS at the carb

If you hear a 'click' when you reconnect the connector, ICS is actuating properly. If you don't hear a click, it is most likely due to a bad ground (it grounds through the Emissions Computer). The mod is to reground the ICS permanently.

 

[LAMBCRUSHER]

grounds and fusible links....I'm wondering if the new bad idle isn't a symptom of low voltage; turning on and off the idle solenoid as the system reaches its threshold.... does the issue develop as the engine has been running after the battery has been charged, or does it do it with a fresh charge, too?...check fuses and wiring to alt; have alt tested at a REPUTABLE auto parts house. very possible that you had one problem and then you have another problem and it displays itself in a similar fashion...

 

[Keith87VT]

So I put a fresh battery in it... Read 12v on dash still had issue. Unplugged green and replugged no sound... So we are gonna do ics ground tomorrow and see if that does anything. if not I am going to start a desmog and pull the carb and have a buddy rebuild it.

 

[Slow Left]

So I put a fresh battery in it... Read 12v on dash still had issue. Unplugged green and replugged no sound... So we are gonna do ics ground tomorrow and see if that does anything. if not I am going to start a desmog and pull the carb and have a buddy rebuild it.

Is the fresh battery holding it's charge?

If not, as mentioned above, suspect that the the alternator is not charging the battery as it should be. If you need the FSMs, you can down load them here:
https://forum.ih8mud.com/threads/fsms.743084/

Yeah, on the ICS, try grounding it following the modification instructions and see if that works. If you permanently ground it and it begins to function properly, then also assume that there is an issue with the Emissions Computer.

You can pull the Emissions computer (behind the kick panel in the lower left driver's foot well), peel back the tabs on the casing and take a look at the circuits/solders on the bread board.
Also, if you follow the wiring diagram in the back of the Body Electrical FSM, you can probably even come up with some electrical tests to see if it is working correctly.
In addition to the ICS, the Emissions computer controls some VSVs (Vacuum Switching Valves) (...and whatever else shows up on the wiring diagram).

 

[Keith87VT]

No the battery wasn't charging alternator is def an issue, but the solenoid should have clicked even if the battery wasn't being refilled as long as it was fresh and reading 12v which it was at the time we tested the solenoid. Or is that assumption wrong? Does anyone have a picture of where to cut the wire to do the ground? And where to ground it to?

 

[Slow Left]

No the battery wasn't charging alternator is def an issue, but the solenoid should have clicked even if the battery wasn't being refilled as long as it was fresh and reading 12v which it was at the time we tested the solenoid. Or is that assumption wrong? Does anyone have a picture of where to cut the wire to do the ground? And where to ground it to?

OK, so there is a problem with the alternator. As mentioned above, I can think of two next steps in the diagnosing/troubleshooting (because it could just be the voltage regulator for the alternator that is bad).
1) Run tests in FSM
2) Have local After Market Shop run tests (maybe for free) - but here you should figure out what tests they are running and how they are measuring...or just giving you a bunch of BS so you buy a new whatever...see FSM to know what you should be testing/measuring

Yes, if functioning properly, the ICS should actuate with a battery that has a full 12V charge. Since it did not, the possibilities are:
1) the ICS is not grounding properly - do modification
2) the ICS is no longer functional, and the ground is good

Search here in the 60s section for Idle Control Solenoid, ICS, Fuel Cut Solenoid etc...for instructions on how to do the modification.

 

[Keith87VT]

So the one good thing in all this is that I have a parts rig with all these parts still in it. So later I am going to do the ground and swap alternators of it still has the issue I am going to pull ics from spare truck and see if that does anything. And if all still fails I'm gonna burn it down... No not really but I will pull my limited hair out and dig into fuel issues and vacuum issues further.

 

[Slow Left]

On the business tip of the ICS, there is a rubber o-ring type seal. The o-ring usually comes included with carb rebuild kits, but you might be able to get a new on from Toyota, too. Also might get lucky and take the old o-ring from the malfunction ICS to a Car Parts or Hardware store and find one of the proper dimensions...

 

[Slow Left]

So the one good thing in all this is that I have a parts rig with all these parts still in it. So later I am going to do the ground and swap alternators of it still has the issue I am going to pull ics from spare truck and see if that does anything. And if all still fails I'm gonna burn it down... No not really but I will pull my limited hair out and dig into fuel issues and vacuum issues further.

Sounds like a plan.

Why not read through the FSM charging system troubleshooting procedures, run the tests you feel comfortable running (on the alternator/voltage regulator you currently have in there) and see if you can diagnose precisely what is wrong? That way, if you run through the tests (as you did, for example, with the ICS) and you swap in a 'new' part, and that same test on the 'new' part shows a positive result, then you can be confident that you have correctly identified and fixed the problem...and learned more about how the system works in the process (which is helpful for future troubleshooting or emergency repairs on the trail/side of the road). If it helps, post up the images of the test procedures here and fire away with questions on steps that don't make sense...

Just know that the charging system can kick out some serious Amperes (remember, it's not Volts that kill, it is Amps...), so you need to work through methodically and follow the steps in the FSM procedures deliberately. And if you don't have the proper tools or are unfamiliar with running electrical tests, then maybe the option of taking it to an Autoparts store or just doing the 'swap and try' method is best...