Okay I just tested the output going to the bottom of the Vacuum Amp. from the VCV (Black line w/ red stripe) and got ZERO coming out of that end (after the Damper).

As Dave (gsxr) mentioned.........one line is the supply vacuum to the VCV..........you've got 20" there..........by your previous photos.

The second line is the output line to the amplifier (on the bottom........the VCV port). That appears to be zero. Double check your work by removing the T and connecting the output line from the VCV directly to the gauge. If it still reads zero with the engine running............the VCV is bad and you need to replace it.

I'll be away from the forum for about one week...........so, Dave and others will continue to help you.

Note there are two connections at the top of the VCV on the IP, right next to each other. One is the input (20-25" vac source), the other is the output (0-15" modulated by the throttle position.

The other fitting, coming out the front/bottom side of the VCV, should be connected to a black tube... this is the vent, and no vacuum or pressure will ever be present here. I don't think I've seen a photo of your VCV connections so I'm not sure if you're connected properly.

EDIT: @Brian - Thanks for the heads up, have fun on your vacation (if thats where you are heading)!

@Dave - I know that the Supply Line going to the VCV has a Y splitter on it, with the bottom going into the top of the VCV; The Supply Line has 20" and I presumed the other side of that Y would have 20" too.

I am going to have to go home 2night and take a look at what we are dealing with here but like I said I tested the black hardline with a the red stripe, the line had ZERO pressure. I'll take pictures of the VCV so we can put that on the table, I am not certain but it looked like it was setup the same way it is in the Diagram.

Thanks,

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

Okay I am sort of in a rush and will be back later but I took a picture of the area the red arrow by the Damper is the VCV black line with red stripe going to the bottom of the Vacuum Amplifier and that reads ZERO.

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

Frank,

That ain't right. With the engine at idle, you should read about 15" vacuum there, and as the throttle is opened, it should drop lower. Connect your vacuum gauge DIRECTLY to the port on the VCV (remove the line with the green damper). If you still get zero, despite a 20" input, the VCV is bad. But first you need to make sure there isn't a line blocked or plugged.

@Dave - Thank you, I will check that today and report back to you; I am going to test it before the Damper (72) @ the VCV where the line goes to the Vacuum Amp. Then I am going to see if there is anything in the line going into the VCV blocking it and report back later tonight!

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

Okay so I had time to sit down and do some testing today and here are my results. I am positive there is 20" going into the VCV, I tested right at the end of the Y that comes into the VCV, so the Y is not the issue.

Then I tested the output side of the VCV (see picture) and again I got ZERO as my result.



So I removed the VCV as much as I could (without pulling that affixed black hard vacuum line) just enough to make sure I saw nothing blocking the input / output on the VCV.

I guess this means I need a new VCV but now here is my problem, the diagram calls it a Vacuum Control Unit, you guys call it a Vacuum Control Valve (I think lol); I can not find either of those on www.***************, I even looked at what I thought was all of the picture that had the word Vacuum in it and could not find it (Here is a link, if it works, to the 87 300TD Wagon Section on BuyMBParts).

I'm probably just looking at the wrong item I am sure it is there; I'll do more research when I get a chance.

Any other tests I can do at this point?

Thanks,

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

If you have 20" going in and zero out, I can't think of any other tests... just plain sounds like a defective VCV (or VCU, to use the FSM term).

According to the EPC, the original part number was 123-300-10-33, which was replaced by 140-300-08-33 (and the 140- number also requires modified connector 116-276-09-29). If you search directly by the part number, it will appear in the catalog... roughly $100 or so, plus the connector (which is $2 MSRP). Here's a photo:

@Dave - You are the man. Thank you =)

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

So I got my VCV in today (thank you for you delivery speed BuyMBParts!) and I popped that jim-jammer in as soon as I had a free moment!

I only had enough time to drive it around the block to see how well it shifted at low RPMs since that is where it was pretty rough and boy that sure made a difference, I can notice even around the block.

I will be doing some Vacuum testing at my earliest convenience however tonight I have too many things on my plate!

Okay so I still have not done any testing so I am just going to report what I have noticed driving to work today since that is the most routine event.

The car shifts much more smooth when I physically change through the gears with the shifter, better now than ever.

I have noticed that somehow the gas pedal is harder to push down, there is more resistance now and it used to be much easier to push it down to where the WOT button on the floor is before I put the VCV in. (As a side note I don't even know if that is because of the new VCV or not however it happened after the new VCV was installed)

Here is something unexpected and definitely noticeable from now to before the new VCV was put in. I go up a hill into the mountains here in NJ every morning on my commute to work, two actually. The first hill I would notice the car would pull in 3rd gear (I keep it in 3 going up these hills normally) all the way or steady until the last 500-700ft where it would sort of drop in RPM/Speed due to a increased incline in the road until it leveled off. This is with consistent pressure on the pedal and it would always feel good an strong considering the weight of this wagon.

Today on my way up that same hill the car was dramatically loosing speed way before the last 500-700ft section that it normally falls back on, and I felt like I had to almost floor the car in hopes to give it more power (which again is also because of the stiffer pedal feel).

I definitely notice a lack of power now, would or could this be caused by a VCV? Again I will do testing tonight to continue where this tread has been going for Dave and Brian and for myself as I too want to make sure the car is tuned properly. However I wanted to express how tired the car feels now that the new VCV is in and perhaps someone has a clue as to what it could be.

Thanks for looking!

- Frank

The lack of power could be a dislodged/disconnected boost line, reducing the signal to the ALDA. The stiff pedal may be due to the VCV installation. There is a notch on the rear of the VCV, this needs to fit over the tang from the IP, which is directly attached to the throttle lever on the other side. If the VCV isn't installed (or adjusted) properly, it *could* possibly cause the stiff pedal... something definitely isn't right, but it's hard to say what exactly.

@Dave - I haven't checked any of the boost lines, which are which? Maybe they are on the diagram and I just haven't payed attention to them. Maybe you are right about the VCV fitting I will re-seat it tonight, I thought it was sitting correctly over that IP tang but I could be wrong, you sent me pages on how to adjust the VCV on this thread somewhere recently if I am not mistaken.

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)

So let me tell you how grateful I am that I have you Dave and Brian helping me with this. I get out of work today and for the heck of it decide that I should put on some gloves and loosen the two 10mm bolts and see if I can line the VCV up better considering I can not see the inside area of it.

How you know your VCV is not correctly affixed: When your gas pedal gets rough after you just installed your VCV.

Instantly I could feel a difference, the car loosened back up immediately. Now time to do some vacuum tests on the VCV to Vacuum Amplifier for some closure!

Be back later!

__________________
'87 300TD Estate (Panzer Wagon, Sold)
'95 E320 Estate (Sabertooth, Sold)
'94 E500 (Stark 1, For Sale)
'04 VW GTI (Rhino, Sold)
'12 VW GTI Autobahn (Shadow)