Hj61 vacuum question

[fishhunt22]

I have a HJ 61 turbo diesel. I took out the alternator with vacuum pump and replaced it with a aftermarket alternator with a separate electric vacuum pump.
It works great but the pump runs all the it seems like. It will stop for a second and start right back up. I don't have any leaks except I did track down one small hose that entires at the first part of the turbo charger intake right after the air filter. If I plug that hose the pump stops. Why does it need vaccum at the intake of the turbo charger. I would like to disconnect it so the pump doesn't run so much

Mike

 

[Tapage]

I'm not an HJ61 expert but that does not make sense .. it's that running to the vacuum sender at the ir box .? ( white thingy ) see the white thing with vacuum lines attached at the air box ..

 

[fishhunt22]

Look at your black tube that runs into your turbo charger intake. Were you see the words turbo charger

 

[fishhunt22]

Why would you need a vacuum in the turbo charger intake?

 

[fishhunt22]

Sorry I didn't mean the turbo charger. I meant to say the intake pipe that says TURBO on it. I have small black vacuum tube that attaches to it. What is it for?

 

[Tapage]

Sorry I didn't mean the turbo charger. I meant to say the intake pipe that says TURBO on it. I have small black vacuum tube that attaches to it. What is it for?

that's from there to the boost compensator on your IP that way your IP know how much " boost " your intake have therefore your engine to adjust fuel accordingly ..

 

[niffa]

I put a new alternator on my 12ht powered hj61 and it came with the vac pump installed on the back as an original does. Why would u want an external vac pump?

 

[niffa]

And it has to run all the time to supply vac to the ip and 4wd activation solenoids, most of the car runs on vac lol

 

[Tim-HJ61]

I've mucked around with my intake system installing the intercooler etc, so don't have the standard setup any more, but am familiar with the vacuum and pressure lines on these engines.

The IP needs a PRESSURE line the goes to the back of the boost compensator/ governor housing. As Tapage says, it provides more fuel under boost conditions. But it's a pressure line not a vacuum line.

The photo that Tapage has shown is, I believe, only to show the air filter, as clearly it's not a 12ht motor.
The two lines that go to the white thingy on the side of the air box are to activate your blocked air filter light. They don't need to be connected to vacuum, or pressure, lines and are independent of them both.

As I recall, there IS a line that goes to the outlet tube of the air box. The purpose of this line is unclear to me, vacuum confuses me. It's to allow the vacuum switches to 'vent' and suck in clear air, or something like that... At a guess.

There is a vacuum line that ends up switching the butterfly flap in the inlet manifold to turn the engine off, and another goes to the idle up controller down low on the accelerator mechanism.

The vacuum pump has to keep the brake and clutch boosters up too, plenty of opportunity for leaks, and also continual usage when the you're driving the vehicle.

I've colored in the pressure and vacuum lines on a diagram and will try to find it.

Tim

 

[John Galt]

The purpose of this line is unclear to me, vacuum confuses me. It's to allow the vacuum switches to 'vent' and suck in clear air, or something like that..

close enough

On the 13B-T, turning off the key switch de-energizes a VSV which transfers vacuum from holding the air shut-off butterfly open, to the air box, so it sucks clean air till the engine shuts down from lack of air.

 

[fishhunt22]

A few reasons why I put a electric vacuum pump on: My original alternator went. I bought a new one from AU. They shipped it over and it was bad. It didn't work. So I shipped it back. They sent me a another one and it was damaged in shipping. UPS said it wasn't packed well so they wouldn't cover any thing. It was repairable but that wasn't the point. I installed it and it ran for a year and started leaking oil around the rotor shaft Finally it fried. Instead of getting another one and dealing with a foreign company, plus customs taxes and shipping I decided to but a regular alternator and a electric vacuum pump. The only real issue is that vacuum line running to the intake. Not the air intake. It runs from the big metal tube that says turbo in red letters. In the middle it has a vacuum line that runs directly to my electric vacuum pump. I don't know why it would need to suck vacuum from that intake I know this picture isn't great but the vacuum line I'm talking about is right under the first metal intake in the middle of the engine. You can't see it but at least you can see the hj61 engine

 

[doug720]

Where are you? The US? If so, check out the alt/Vac pump set from an Isuzu 4BD2. In another thread, I suggested this, and as I recall, it worked out great. The Isuzu's are all over the US and have a great parts availability, both OEM and aftermarket.

Just an idea.

Doug

 

[fishhunt22]

I wish I talked to you a year ago. Do you think the belts will line up? Yes in the USA. I'm going to keep the current setup for now. I just really want to know the purpose of that one vacuum line. Thanks for the info

 

[Creeker]

The belts line up but you need to mod the bracket a little bit. I have specs for the alternator that I used and a sketch as to how I fabbed the bracket if anyone's interested.

 

[fishhunt22]

I had to fab the alternator bracket also when I but in that alternator with pump. It worked great

 

[Siifo Diaz]

The belts line up but you need to mod the bracket a little bit. I have specs for the alternator that I used and a sketch as to how I fabbed the bracket if anyone's interested.

can i have them please, much appreciated!

 

[johnnyporp]

can i have them please, much appreciated!

Did you get the diagrams for the set up on the Isuzu alt

 

[kevin in okinawa]

yes please!

The belts line up but you need to mod the bracket a little bit. I have specs for the alternator that I used and a sketch as to how I fabbed the bracket if anyone's interested.

Yes! if you're still around, can you tell us more about this Isuzu alternator? I like to have a Plan B.