What a difference a new vacuum tube makes

[gregoron]

I recently changed my Jetta's vacuum tube between the intake manifold and the fuel injectors and the engine idles better and has more pickup. This is after 130k miles. I'd suggest replacing these tubes at 60k in case you overlook them. They're cheap and easy to replace.

 

[RF Overlord]

Vacuum tube? I thought that was something used in guitar amplifiers...

 

[EdwardC]

I thought most stuff was transistorized nowadays...

 

[Tegger]

Originally Posted By: gregoron
I recently changed my Jetta's vacuum tube between the intake manifold and the fuel injectors

Surely you're referring to the big plastic pipe between the air cleaner and the intake manifold?

Our 1966 Zenith black-and-white television had vacuum tubes. It was fun to watch them glow in the dark. You had to peer through the holes in the rear of the TV to see them, and they were like very dim light-bulbs. Fascinating for us kids.

 

[gregoron]

Originally Posted By: RF Overlord
Vacuum tube? I thought that was something used in guitar amplifiers...

They make these too, but it won't fit in your engine. Check out lines and hoses as well.

 

[gregoron]

Originally Posted By: Tegger
Originally Posted By: gregoron
I recently changed my Jetta's vacuum tube between the intake manifold and the fuel injectors

Surely you're referring to the big plastic pipe between the air cleaner and the intake manifold?.


No, it activates the fuel injector solenoid when there's negative pressure from the intake manifold. Not all cars may have it, but if yours does, it's a no brainer to replace if it's old and leaking.

 

[datech]

Back when I worked for UNIVAC I found a special tube puller made to make changing them out hot tubes easier. Those models were a bit before my time, but one of the old timers told me one trick they used was to turn off the lights and look in the CPU cabinets to see if any of the tubes weren't glowing.

 

[yonyon]

I find it extremely hard to believe VW used vacuum tubes to operate the injectors on a car. I could see maybe doing that on a stationary engine, but a car is going to bust tubes way too much.

 

[clinebarger]

Originally Posted By: gregoron

No, it activates the fuel injector solenoid when there's negative pressure from the intake manifold. Not all cars may have it, but if yours does, it's a no brainer to replace if it's old and leaking.


I think your talking about the Fuel Pressure Regulator vacuum line. When I clicked on the thread I thought Curtis Mathes TV.....

 

[Tegger]

Originally Posted By: gregoron
Originally Posted By: Tegger
Surely you're referring to the big plastic pipe between the air cleaner and the intake manifold?.

No, it activates the fuel injector solenoid when there's negative pressure from the intake manifold. Not all cars may have it, but if yours does, it's a no brainer to replace if it's old and leaking.

Is this engine a diesel?

 

[MolaKule]

Originally Posted By: Tegger
Originally Posted By: gregoron
I recently changed my Jetta's vacuum tube between the intake manifold and the fuel injectors

Surely you're referring to the big plastic pipe between the air cleaner and the intake manifold?

Our 1966 Zenith black-and-white television had vacuum tubes. It was fun to watch them glow in the dark. You had to peer through the holes in the rear of the TV to see them, and they were like very dim light-bulbs. Fascinating for us kids.


Gee Tegger, you're old as dirt, llke me!

 

[SrDriver]

Our first TV was an RCA portable around 1952. Drug stores sold vacuum tubes and had a tester.

 

[gregoron]

Originally Posted By: clinebarger
Originally Posted By: gregoron

No, it activates the fuel injector solenoid when there's negative pressure from the intake manifold. Not all cars may have it, but if yours does, it's a no brainer to replace if it's old and leaking.


I think your talking about the Fuel Pressure Regulator vacuum line. When I clicked on the thread I thought Curtis Mathes TV.....


Bingo!

 

[gregoron]

Originally Posted By: Tegger
Originally Posted By: gregoron
Originally Posted By: Tegger
Surely you're referring to the big plastic pipe between the air cleaner and the intake manifold?.

No, it activates the fuel injector solenoid when there's negative pressure from the intake manifold. Not all cars may have it, but if yours does, it's a no brainer to replace if it's old and leaking.

Is this engine a diesel?


No. It's 4 cylinder 2.0 gas engine (AEG) aka "2.Slow".

 

[Zaedock]

Originally Posted By: SrDriver
Our first TV was an RCA portable around 1952. Drug stores sold vacuum tubes and had a tester.



U-Test-M !!!!!!!

 

[andyd]

My dear wife's 528e has had issues for a while. My last go 'round to fix an intermittent stutter included tightening the clamp on the breather hose that I had replaced last summer. The idle is much better now.

 

[artificialist]

Is the OP talking about a variable geometry intake manifold? One that switches between long narrow runners and short wide runners in order to get a wide powerband?

That is what I think he is mentioning, but I could be wrong.

Ford "Split port injection" engines are built this way, and the vacuum device would often fail and make the engine run poorly.

 

[asand1]

No it is a vacuum line that goes to the injectors.

 

[gregoron]

Artificialist, it's the vacuum line from the intake manifold to the fuel pressure regulator as Clinebarger pointed out above. My engine doesn't have a variable intake manifold.

The rubber vacuum hose/line/tube was cracked and leaching air in so the FPR wasn't working properly giving the engine an overly rich fuel mixture. When I replaced it with a new hose, it idled and accelerated better. It might improve my mileage too, but it's too early to tell.

 

[gregoron]

Asand1, no it's not that line. It's a single tube only going from the intake manifold to the fuel pressure regulator. Fairly easy to replace as it had no clamps. Just a rubber tube with a cloth lining. I used a regular rubber tube from O'Reilly's as a replacement.