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Apparently I have time on my hands because I thought about replacing the Double Throttle Valve.
As you may or may not know, getting a working version of these is near impossible. And even if you could get one, would you? All it does is keep the throttle plates closed during warm up so you can't over rev the engine on a frozen day.
What I discovered is the under normal circumstance, the default is OPEN and only when the car is warming up does the water thermo wax valve allow vacuum to pull the actuator in, . . .. Running the car with this valve broken doesn't really do anything as long as you don't high rev on cold day prior to warming up. . .. . But as you know, the failure is the ruptured diaphragm which causes loss of vacuum on that line and raises the overall vacuum level in the car during warm up.. . .Vacuum leak,
The spring action does come from the DTV so removing it just lets the plates in the intake just flop around. . . .So you gotta keep it in place or you have to wire the plates open or remove them.
For $29.99 I saw an EGR valve for a jetta 1.9 diesel and thought what the F. . . .
Aftermarket Products Fitment Type: Direct Replacement Manufacturer Part Number: EGV1079
I then removed the Linear Vacuum Actuator and lined it up. . . . . .I then thought why can't I also use the diaphragm for the EGR valve which is also no longer available.. . .Apparently the EGR only opens up in 5th gear so blanking it off may be the better solution. .. . .I need a broken Rx7 EGR to experiment with. . . Anybody got one?
But back to the Double Throttle Valve. . Below are the pics. . . . I gotta bend a piece of sheet metal next and line it up. . . It's slightly large, but not impossible. There is enough room if you get creative with your bracket. .. . .And for 30 bucks, it's cheap enough to go through the exercise and not care if I fail.
Anybody got better ideas or comments let me have it,
Stock Jetta EGR valve After Removal original lower bracket removed and pushed out of the way. . . .Looks like I could enlarge that lower hole on the actuator. . . .. .i could probably use the upper hole if I make the bracket right but the upper hole is a little large for the pin and may get sloppy.. . EGR Diaphragm removed to see if it might work for the no longer available EGR valve on the 86 Rx7 S4 . . . comparison in size. . . Looks I could get it to fit with the right sheet metal bracket.
Notice the final location of actuator relative to intake lever.
During the install, you have to make sure the actuator plunger slightly pushes on the intake plate lever in a neutral state
What I like about this pneumatic actuator is the that you can rotate the lever relative to the base.. . .This allows you to position the outlet of the vacuum line underneath everything.
What I don't like about my design is the lock nuts on the 10-32 screws. They are too close to the intake plastic and could possibly rub. I will most likely use a low rise nut on the back side of the screw to get away from the intake plastic some more. .. . ..If I bend the bracket slightly I could get more clearance.
The hole in the actuator lever is not a perfect size for the intake plate lever/pin. . .It is slightly bigger that the shoulder on that screw. . . .Just slightly.. See the side pic. . .. It's functional.. . . .Always have the lever pushing on it and it's not a big thing.
I had to stack up washers to get the offset I needed.. . .Kinda cheapo solution.
The bracket you make only needs to be a single plate. . . . I tired to make a bent one with an offset and it came out cruddy cause I didn't have a sheet metal brake.
Thankfully, for ease of install, all you need to make is a single piece of aluminum sheet metal as the bracket.
Actuation happens at around 10" vacuum. . Maybe less.
The Actuator by itself, no bracket, can be bought for $ 18.00 on Amazon, So once you set it up, it's pretty cheap. They probably sold millions of those engines in Europe.
labwork EGR Valve Actuator Exhaust Gas Recirculation Valve 038131501E Replacement for VW ALH TDI 1.9L Diesel Turbo 1998-2003
Just a note, the vacuum leak should not matter too much, as there is a delay valve that barely lets any air through (I still capped the line tho). I really like your installation!
09-29-21, 08:52 PM
