Does it matter what order you adjust warm/cold pressures

[Tidybuoy]

I'm am very close to graduating into the "I understand CIS" club. And everything I have learned came from the experts on this board. I only wish I paid better attention in the early days as it took me about a year to get the car running perfect.

Today, it is running perfect. Although I replaced just about everything (i.e., injectors, seals, accumulator, check valve, internal pressure regulator, ect..) it turns out that the only thing that changed the way the engine runs was to get my fuel pressures corrected. I did this by buying a couple of used wurs and using the best parts of each to create a good wur. Then I adjusted the pressures by taking apart and taping out the plug and putting it all back together and tapping in the plug and barrel.

My only questions left:

1) does it matter if you adjust warm or cold pressures in a specified order. I adjusted my cold pressure first and then had to tap in the barrel very slightly to get the warm pressure up. It appears that both pressures are now within spec for my #033 wur (1.4 bar cold and 3.2 bar warm.

2) Vacuum connection on wur - CIS primer calls for 3.2 bar and 3.6 bar vacuum. I'm not sure I understand how to test for this. I disconnected the vacuum line and plugged but I don't see any or much change in the warm pressure. Also, I only unplugged the bottom/side vacuum but now I'm thinking I should have removed the top too. What is the correct procedure for checking this.

3) Fuel Leak Down. In my process of making numerous adjustments (including the shims on the internal pressure regulator), I broke the o-ring on the tip of the piston. I replaced with an o-ring that seems to work but now I'm wondering what the proper leak down time should be. I leaking down to zero in about 1.5 hours.

Thanks & happy Thanks Giving!

[ossiblue]

With regard to which you should adjust first, usually the warm control is done first, here's why.

If you set cold control first, you never know if the bimetallic arm ever completely releases from the coil springs that move the pin into the diaphragm, when things are fully warmed. Then, when you fully warm the wur and the warm control pressure is too high, say, you will have to move the housing of the diaphragm upward within the wur body (away from the pin.) Now, once you have moved the position of the diaphragm relative to the pin, your cold pressure will be off because the pin will be compressed by the bimetallic arm to its former position but the diaphragm itself has moved upward (in this example) resulting in a too low cold control pressure (again, in this example.)

Additionally, if you set the cold first, there is the possibility that you tap the plug down to a point where it doesn't fully release from the coil springs when things warm up. That means the bimetallic arm is playing a part in the warm control setting which it should not.

From your posts, however, it sounds like you did it in reverse and things are working well. I must comment, though, that you didn't say if you adjusted the cold pressure using the charts for ambient temps for your wur. If you didn't, then you will need to re set the cold correctly.

[Tidybuoy]

Thanks Ossiblue. I got a lot of info for fixing my wur from a collection of your posts and that's been a huge help.

That said, I might have to re-adjust the cold pressure as it was different this morning from the last time I checked (I've been keeping the pressure gauge connected) for about a week so that I can monitor all the pressures at various operating conditions). It was a little lower this morning and about 1.1bar

At this point the car is running better than it ever has and I know that I've got it close. After years of reading about adjusting the wur, it seemed like it would be a difficult job but it was actually very easy. This weekend, I will tap out the "plug" just a bit and then reset with the warm pressure sent perfectly first.

I need to do all this when and use the specs for specific ambient temperatures.

Thanks!