Since you have it connected to the cold start valve you are actually not measuring system pressure, you are measuring only control pressure. The only way to measure system pressure is to connect to the top of the fuel disty with a gauge and a shut-off valve and see what she reads with the valve closed.
Your cold control is a bit high (should be 25PSI), but given that it's warming up outside that might be in range. I don't have my chart handy to be sure. However, since the car only runs cold for a short while, the warm control is more important. Your pressure of 48 is low. It should be 55 +-2. However, again, you are measuring at the cold start valve, through the fuel disty, so some pressure might be lost and that might be a decent number.
At any rate, it's certainly close enough that you should be able to start. And you won't get the control pressure you need when warm if the system pressure is below about 60 anyway. I think your fuel pressures are fine.
Your next steps are as follows:
1. Check static timing. This means finding TDC on the crank, popping the upper timing cover and looking for the cam gear dimple to be level with the top of the head, and pulling the disty cap and verifying that the rotor is pointing to the hash mark for #1 cylinder. I strongly suspect your wabbit has hopped a tooth on the belt.
2. Check for vacuum leaks EVERYWHERE!
3. Check the injector sprays. I took 4 glass Starbucks jars (my wife drinks the crappacinos) and used a coat-hanger to connect them together. Get some channel locks or vice grips and grab the hex part where the fuel line meets the injector. Use the top of the valve cover as leverage and pry those suckers out. They must be pried up and toward the firewall, not straight up.

Hope that helps!

Thomas

Forget the timing. Your first post said it wouldn't take gas. If it accelerates to 4000RPM your timing may be off a bit, but you haven't hopped a tooth.

This is most likely a vacuum leak somewhere, or a vacuum advance issue. You need to get all your vacuum lines replaced or checked. Does your distributor have 2 places to connect vacuum lines? If it does, you need to make sure that the one on the front of the bubble is connected to the filter side of the throttle body and the one on the back is connected to the manifold side of the throttle body. Faulty vacuum advance can cause all kinds of issues. The fact that your car idles high is an indicator of vacuum leaks.

Check under the driver's side wiper, in the rain tray. There's often a device that has two 3-pin connectors on it. It's the digital idle stabilizer. If you disconnect both connectors, one is female and one is male. You can connect them together and bypass this little sucker.

If you eliminate ALL vacuum leaks, you're looking at fuel issues, plain and simple. Either a clogged fuel filter or a faulty fuel pump or possibly a stuck plunger in the disty. The fact that your car works at lower RPM, but has issues at higher RPM (when more fuel pressure is needed) would seem to indicate that you have low fuel pressure. However, without connecting to the proper port you can't measure your pressure accurately, so you're left to shotgun it by replacing the filter first, then the pump.

Thomas

OK. One at a time:
1. I'm not on autopilot for the Bentley and I'm 400 miles from my Bentley. Check here:
http://www.geocities.com/jonnyguru/vw/fpressure.html
Is that how you have it connected? When you close the valve is when you measure system pressure, no other time. If your system pressure is only 52 then you have a plugged fuel filter, bad fuel pump, plugged fuel pump screen or sticky system pressure regulator. When the valve is closed no fuel is going to the CPR or to the fuel distributor. (at least your fuel pump runs...my '81 just emitted some smoke from under the dash yesterday when I removed it from its winter rest...no fuel pump noise at all. <SIGH!>)
2. Did you jumper the fuel pump relay per the Bentley and the frequency valve isn't buzzing? But when you turn on the ignition the valve buzzes? I don't have my schematics handy...but you don't have a bad frequency valve. Since the pressure changes when the valve clicks or buzzes, it still sounds like you don't have the pressure kit connected correctly or something. Do you have the old style fuse block with the long, cylindrical fuses?
3. The fact that the control pressure is also 52 again says you don't have the kit connected correctly. Look at the Bad Habit Rabbit site I listed above and re-do your pressures with the fuel pump relay jumpered out and the ignition in the ON position, engine off.
4. Any chance you could take a picture of your fuse/relay block? Something is very amiss with mine and I'd love to look at one to make a comparison. There's a '79 in the pull-a-part but no relays in it...I might have to go back and rob that fuse/relay block for my '81. If you can send a pic to thomas_covenant_98 at yahoo dot com I'd sure appreciate it.
Let me know what you find on 1-3 above. Something just doesn't seem right.

Thomas

If the freq valve comes on with the pump then all is well there, no worries.
So, you're saying that if you connect the jig to the system and CLOSE the valve (system pressure) you read 74PSI. If you OPEN the valve (control pressure) you still read 74PSI?
Yep. Your CPR is clogged bigtime. Pull the fittings off of it. Pop it off the block. You'll find there are screens on the openings. They need to be cleaned. They are probably filled with the same goop that's in your tank.
I'm with you on the tank install...that's a big job...not one I want to do. Bonus is that these older cars (without the in-tank pump) have a rubber hose in the tank that goes bad, causing the pump to suck air on hard right turns and stall the engine. With your new tank that won't be a problem.

Thomas

Glad you figured it out!

What's weird is that your 49 is great for hot control pressure and 30 is great for cold control pressure. It's like the goofy thing is operating backwards, which is pretty much impossible...unless you've somehow maybe got the spring turned around? Seems unlikely. It runs and starts great...I don't know what to tell you. I suppose you could put the washers back in and see what happens...if it were me, and the car is running deluxe again, I'd leave it alone.
What's even weirder is that it seemed to be working OK in your first posts...when it seemed to go up as it got warm.

Thomas

Very glad to help! If you can get a chance to grab a pic or three of the fuse panel that would help me!
Couple of things:
1. The valve is called the Aux Air Valve. Just so you know.
2. The used CPR is working, call it good! I guess you could put the washers into the old one and try it...but I'd just toss it.
3. The engine shouldn't stall, just drop RPMs, when you pinch that line. The drop in RPM should cause the idle boost solenoid (mounted on the pass side strut) to kick on. It sounds like your idle was adjusted incorrectly. Warm the car to operating temp. Verify the idle is where it should be. Turn off the car. Disconnect the electrical connector from the boost solenoid(s) (there will be 2, if you have Air Conditioning). Start the car. If it dies or idles much lower, then the idle was adjusted wrong. Go ahead and adjust the idle back to 950+-50RPM. Turn off the engine and reconnect the boost solenoid. Now it'll work right.
4. I've never heard that catching fire is common in these cars over other cars. Without knowing why it's hard to say...power steering or auto trans fluid on the manifold...a short in the electrical system...fuel spewing from a ruptured line...these things happen in all cars. I don't think wabbits are more or less likely to have this happen.
5. Go to forums.vwvortex.com for excellent instructions on replacing the top. Look for pictorials in the cabby section as well as Forrest King's excellent write-up. Lots of info there. Also cabby-info.com has great info on top replacement. Don't try this without these guides. They will save you tons of time and trouble!

Thomas