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Where in my profile might I find this?

 

With defrost on my ac idle up valve turns on does anyone have ideas based of off this?

 

In most cases, the A/C runs whenever the defrost mode is selected. This is because the A/C removes water vapor from the air. The idea behind the idle up is to make up for the drag of the A/C compressor running. I hope this helps.

 

This might be of use to you: https://www.sq-engineering.com/tech-articles/wiring-diagrams-and-diagnosis/

See the translated 20V Silvertop wiring diagram: https://www.sq-engineering.com/wp-content/uploads/2018/11/Toyota-4AGE-20v-Wiring-Diagram.jpg

There are some ECU pinouts and other things too. More stuff for the blacktop engine, but I found it's all pretty similar when I was working on getting the Silvertop in my parts car running.

 

We might have an interpretation or terminology issue here. When I think of IAC, I think of the IAC Valve (idle air control valve) that is located just under the throttle body. That IAC valve is not involved with the A/C system operation - at least in the aspect of increasing the idle speed of the engine when the load of the A/C compressor is added to the engine. Consistent with the wiring diagram provided by CanadianCorollaGTS, it shows the normal VSV1 A/C Idle-Up VSV, which is controlled by the ECU. When the ECU gets the input that the A/C compressor clutch has engaged, the ECU activates this VSV. The VSV then opens it's valve to allow air to flow into the intake manifold (bypassing the throttle body). It may be possible this VSV has failed, or it may not be connected to the wiring harness, or (if the engine in this application was swapped it) it may not even be present.

 

I'll have to look at that but the valve that opens on the fire wall to increase air flow when any load is on the motor does work. I'll find the vsv and test light it. Thank you very much for this information.

 

You have defrosters for two windows - the windshield and the back window. Which one are you defrosting and the engine speed increases because of it?

 

The rear ones I haven't tried the front

 

The rear defroster is electric. It has nothing to do with A/C. For large electrical demands, the ECU does use the IAC valve to provide a bit higher idle speed. That does not involve the VSV that is shown in the wiring diagram.

 

Okay then with 12v and air pressure the vsv should open correct

 

With 12V, the VSV should open. With vacuum, it should allow air to flow through the valve body. The vacuum source is the intake manifold. Or you can test it with the car's hoses removed and with some temporary vacuum hoses attached and put some light air pressure or vacuum on one side to see if you get air flow.

 

I'm going to look at the wiring diagram to make sure I know where everything is and what I'm looking at I will get back to you after I have either confirmed the vsv works or confirmed it doesn't work, thank you again

 

In post #10, I had asked you to post a picture. You haven't done that. If you do, I most likely can tell you what VSV your picture is showing. Probably need a closeup of the VSV and one further away, showing the entire firewall, so I can see where it is exactly on the firewall.

 

I'll give you two right now close and far

 

I think you may have resolved your problem then?

That VSV has a part number on the metal bracket, which I cannot make out on the picture. Perhaps you can make out that part number and provide? It would be in the form of xxxxx-xxxxx.

Also, in your picture, which was the hose that was collapsing, and what was that hose connected to on the other end? Sounds strange that a hose would collapse only when energizing the VSV.

 

It looks like it going to the intake I'll take a better look again when I'm home, however after changing the line it still doesn't hold idle with a on

 

If it was going to the intake manifold, then it would have been collapsed before the VSV opened also (there would have been intake manifold vacuum on one end, and the VSV would have been capped off on the other end, so the hose was under full intake manifold vacuum).

When you get home, see if you can get the part number off of that VSV. It looks very similar to the A/C idle up VSV I have on my 93 Celica convertible - just mounted in a very different place. It has an adjustable orifice opening screw on it to adjust air flow past it - meaning if your VSV actually works, the screw could have been adjusted to block off the orifice so that now air passes through.

 

If it was going to the intake manifold, then it would have been collapsed before the VSV opened also (there would have been intake manifold vacuum on one end, and the VSV would have been capped off on the other end, so the hose was under full intake manifold vacuum).

When you get home, see if you can get the part number off of that VSV. It looks very similar to the A/C idle up VSV I have on my 93 Celica convertible - just mounted in a very different place. It has an adjustable orifice opening screw on it to adjust air flow past it - meaning if your VSV actually works, the screw could have been adjusted to block off the orifice so that now air passes through.

I'm not entirely sure this diagram pertains to your specific vehicle, but it looks like it does. And if I look at this diagram properly, it appears you have the two hoses cross-connected (on wrong ports) of the VSV, based upon the pictures you previously provided. You may need to take a look at this diagram and your setup (when you get home) and evaluate your hose connections.
View attachment 417588

Thank you very much I will definitely look at that and try that out my car is a ae101 so that is very likely

 

I'm not entirely sure this diagram pertains to your specific vehicle, but it looks like it does. And if I look at this diagram properly, it appears you have the two hoses cross-connected (on wrong ports) of the VSV, based upon the pictures you previously provided. You may need to take a look at this diagram and your setup (when you get home) and evaluate your hose connections.

 

Changed the hoses and now have a low idle I tried to change spark timing which helped a little bit kind of at a loss now not going to lie

 

Take both hoses off of that VSV temporarily - noting the proper way to put them back on. Put a new hose that is 2-3 ft long on the VSV nipple that the hose coming from your clean air inlet to the throttle body was connected to.

1. With engine off and key out of the ignition, try blowing air into that hose. You should not be able to blow any air through the VSV. Does this past the test?
2. If that checks our right, then start the engine and let it idle. It likely will idle a little faster due to the hose connected to the intake manifold is now sucking in air. Check that out and see if that hose removed from the VSV that is connected to the intake manifold is pulling air through that hose, or is pulling a vacuum on that hose by putting your finger over the free end of the hose. Does this past the test?
3. Next, take the new hose you temporarily connected to the VSV and try blowing air through the hose. You should not be able to blow any air through the VSV. Does this past the test?
4. Next, with the engine still idling, turn your A/C on. Make sure the compressor is engaged and that your radiator fans are both running. Does this past the test?
5. Last, take the new hose you temporarily connected to the VSV and try blowing air through the hose. This time, you should be able to easily blow air through the VSV. Does this past the test?

After you do these 5 steps, provide feedback if all 5 were successful, or if any of the 5 steps were not successful. We'll figure this out yet.

 

Take both hoses off of that VSV temporarily - noting the proper way to put them back on. Put a new hose that is 2-3 ft long on the VSV nipple that the hose coming from your clean air inlet to the throttle body was connected to.

1. With engine off and key out of the ignition, try blowing air into that hose. You should not be able to blow any air through the VSV. Does this past the test?
2. If that checks our right, then start the engine and let it idle. It likely will idle a little faster due to the hose connected to the intake manifold is now sucking in air. Check that out and see if that hose removed from the VSV that is connected to the intake manifold is pulling air through that hose, or is pulling a vacuum on that hose by putting your finger over the free end of the hose. Does this past the test?
3. Next, take the new hose you temporarily connected to the VSV and try blowing air through the hose. You should not be able to blow any air through the VSV. Does this past the test?
4. Next, with the engine still idling, turn your A/C on. Make sure the compressor is engaged and that your radiator fans are both running. Does this past the test?
5. Last, take the new hose you temporarily connected to the VSV and try blowing air through the hose. This time, you should be able to easily blow air through the VSV. Does this past the test?

After you do these 5 steps, provide feedback if all 5 were successful, or if any of the 5 steps were not successful. We'll figure this out yet.

Going to run through that tomorrow then get back to you, Im also cleaning my throttles they have a gummy liner

 

Well I went to start the car and boom no spark, honestly I have no idea what my car is doing. The vsv checks out fine though it definitely is working.

 

What DTC's do you have? Was the check engine light on when the engine was last running?

 

Check engine light wasn't on and but it was on when ignition was switch on, I'm not sure what dtc's how do I check?

 

Capacitor problems on the first 10 years of EFI engines is pretty well documented. They don't all have problems, but there is enough issues of them to not dismiss any ECU from being a source of a problem. Just stating what was stated above and stated well.