1HD-T AC idle up (1 Viewer)

[dcruiser666]

I have been looking for information here on how the ac idle up functions on a 1HD-T. On my 3B there is a valve on the inner fender connected to a vacuum switch on the IP that presses the fuel linkage forward. My 1HD-T came with ac from the factory but I cannot find anything vacuum or electronically actuated to perform this function. Does anyone know?

 

[Jroc561]

Im pretty sure its this guy:

 

[dcruiser666]

Hmm, that part is not installed on my pump. Can anyone else confirm that's what it is? Looks very similar to the idle up linkage on the 3B. @Jroc561 if that has a vacuum tube routed to it, where is it coming from?

Wonder why that would have been removed or perhaps not installed to begin with...

 

[SHREDwagon]

Quite obviously you do not have "factory A/C" and this engine is not in an 80.

Assuming this swap is paired with a manual, you most likely need to find pictures of a Manual A/C set-up. There's already HD + manual swap threads on here detailing A/C set-up without requiring another thread.

The A/C idle-up Actuator is part #88031-12150

Unsure why you are comparing ANYTHING on this motor to a 3B?

 

[KiwiDingo]

Hmm, that part is not installed on my pump. Can anyone else confirm that's what it is? Looks very similar to the idle up linkage on the 3B. @Jroc561 if that has a vacuum tube routed to it, where is it coming from?

Wonder why that would have been removed or perhaps not installed to begin with...

View attachment 2202306

From looking at that pic of your pump it definitely had all the AC idle up parts attached at one stage. It wouldn't be hard to get the parts required and get it working again.

The vacuum lines come from the vacuum pump but it goes through the AC solenoid first. It only increases the idle when the compressor clutch is engage. Pretty simple to put back in also.

 

[dcruiser666]

Quite obviously you do not have "factory A/C" and this engine is not in an 80.

Assuming this swap is paired with a manual, you most likely need to find pictures of a Manual A/C set-up. There's already HD + manual swap threads on here detailing A/C set-up without requiring another thread.

The A/C idle-up Actuator is part #88031-12150

Unsure why you are comparing ANYTHING on this motor to a 3B?

Thanks for the part number, and thanks KiwiDingo for the info.

You are correct, this motor is on a stand right now and it's going into a 3B powered 70 series. Only reason for referencing the 3B is because it also has AC so the electronic and vacuum parts are already installed in the truck. I was curious if the 1HD-T with AC does not operate with the same technology as the idle up component on the ip isn't there. I assumed this aspect would be plug and play so I was confused. In any case, my question is answered. I'll look for these manual swap threads and won't ask questions about it here.

 

[KiwiDingo]

In any case, my question is answered. I'll look for these manual swap threads and won't ask questions about it here.

Pfft... Ask away mate. This is exactly what this section is for.

There's already HD + manual swap threads on here detailing A/C set-up without requiring another thread.

Unsure why you are comparing ANYTHING on this motor to a 3B?

I see zero reason why someone can't ask a technical question in the tech thread section. Yes you might be able to find some info in a build thread but finding specific technical information in build threads isn't their intended purpose. Asking those questions here like he did is 100% the correct thing to do.

Also if you read what he wrote you would understand exactly why he was comparing this to a 3B engine

 

[dcruiser666]

Pfft... Ask away mate. This is exactly what this section is for.



I see zero reason why someone can't ask a technical question in the tech thread section. Yes you might be able to find some info in a build thread but finding specific technical information in build threads isn't their intended purpose. Asking those questions here like he did is 100% the correct thing to do.

Also if you read what he wrote you would understand exactly why he was comparing this to a 3B engine

Yeah, not sure why my question would be inappropriate here...

Anyway, like you said, I couldn't find any specific information on the manual idle up conversion. Would it be more than just using the hand throttle when I turn on the AC?

 

[SHREDwagon]

Yeah, not sure why my question would be inappropriate here...

Not inappropriate, but if you had looked in the FSM you would have seen that the vacuum line comes off the Vacuum Switching Valve (VSV) and the idle-up operation would have made perfect sense. Point being that when engaged in a diesel swap, which you did not state - it's a good idea to have the appropriate FSM and crack it open. A swap is not a 1-Banana job and you're asking if you can use your hand throttle to idle up with the A/C clutch engaged.

This thread may be of help:
euro-1hd-ft-turbo-diesel-h151f-5-speed-manual-lhd-96-usa-swap

 

[KiwiDingo]

Yeah, not sure why my question would be inappropriate here...

Anyway, like you said, I couldn't find any specific information on the manual idle up conversion. Would it be more than just using the hand throttle when I turn on the AC?

As funny as it sounds using the hand throttle to increase RPM when the AC is on is basically in a nut shell what the AC idle up system does, some models also use the idle up function during turning to assist steering.

That being said lots of vehicles either don't have it or it isn't adjusted correctly anyways to work and just have their idle speed slightly higher. It's really no big deal either way.

 

[KiwiDingo]

Not inappropriate, but if you had looked in the FSM you would have seen that the vacuum line comes off the Vacuum Switching Valve (VSV) and the idle-up operation would have made perfect sense. Point being that when engaged in a diesel swap, which you did not state - it's a good idea to have the appropriate FSM and crack it open. A swap is not a 1-Banana job and you're asking if you can use your hand throttle to idle up with the A/C clutch engaged.
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It might not be a 1 banana job but you sure sound like a monkey carrying on like that! No one's forcing you to reply to his questions and there's plenty of others who are more than happy too help.

 

[SHREDwagon]

using the hand throttle to increase RPM when the AC is on is basically in a nut shell what the AC idle up system does

I'll leave it to you.

 

[dcruiser666]

you're asking if you can use your hand throttle to idle up with the A/C clutch engaged.

Both operations, hand throttle or ac idle up, will move the exact same lever on the ip correct?

 

[KiwiDingo]

Yes, correct

 

[Jroc561]

Would there be any con to removing the idle up? Besides the extra strain on the Alternator? Can you just plug the vacuum?

 

[dcruiser666]

Would there be any con to removing the idle up? Besides the extra strain on the Alternator? Can you just plug the vacuum?

According to the build thread shredwagon shared, with a manual transmission the 1hd doesn't really care about the ac idle up. I don't think anything is noted about implications on the alternator though.

As well, I think I really misunderstood something here. "Manual A/C set-up" gave me the idea that people were performing some kind of modification to convert the automated ac idle up to a manual system, something that sounded very odd to me. The hand throttle idea seemed like a no-modification-needed solution to that - turn on the ac and adjust hand throttle up ~100rpm.

Yes, this motor will be joined with a manual transmission. Going to give it go with the vacuum plugged before deciding if I should spend money on the idle up parts. Didn't originally include info about the swap because I didn't want to have a discussion about that, just wanted a quick answer about an engine accessory on a motor that is new to me. Thanks to all for sharing information

 

[SNLC]

Im pretty sure its this guy:
View attachment 2202299

Yes that is the ac idle up actuator on the pump.

Can really on be there things
Actuator
Vacuum valve
Switch

Cheers

 

[roscoFJ73]

Would there be any con to removing the idle up? Besides the extra strain on the Alternator? Can you just plug the vacuum?

If the fast idle up is adjusted properly, you barely notice it. Ive had it on all my landcruisers and it works fine.

 

[MHS]

Hi there everyone!
I own a 1HDFT H151f 80 series. The car was stalling a lot, especially at stops and stationary turning of the wheels. I did some research and checked my PS and AC idle up calibration. To my surprise the AC idle up vacuum hose had been unplugged, I plugged it back in and immediately the rod pulled back in and my idle went up to 850. So it all went well!

I drove the car with the Ac on and it didn't stall however turning the steering caused it to stall. I checked the PS vacuum hose at the opposite end of the AC hose and it felt like it was there. I traced my finger along it and I turns out the hose had been cut off and it was squeezed so tightly that there wasn't any vacuum leak.

If you've read this far please bear with me.

1) I don't have where to plug this end of the hose to. So any help would be great help. I've looked at the 1hdft vacuum diagram but im guilty of not being wise enough to understand.

2) Secondly I blocked this hose off with a screw to prevent any vacuum leaks but now my AC idle up isn't working anymore either, as in the rod isn't pulling itself back anymore.

There is vacuum in the VSV, there is vacuum at the opposite open end of the PS incomplete hose. But it isn't still working. Any thoughts?

Any help would be of great value and cheers in advance to anyone willing to help out

 

[MUDZLLA]

If the fast idle up is adjusted properly, you barely notice it. Ive had it on all my landcruisers and it works fine.

I think my HDJ-81 automatic with idle up is set a bit high as it almost drives me into the car in front of me when it kicks in at a stop. So about 100 rpm idle up is spec when in drive at a stop or in neutral?