CIS - cold pressure very high

[djb25]

Hi everyone,

I have been working on a cold start problem with my car for a couple of weeks now (off and on working on it, that is). Car is a '77.

In a nutshell, the car fires and then stalls immediately.

I hooked up some gauges and found my cold pressure to be around 70 psi... exactly the same as my system pressure.

I've determined that this pressure is way too high... but I don't know where to go from here!

Any help would be greatly appreciated!

- Damion
'77 911S

[don gilbert]

blocked retun line, unscrew return line ane see if you can blow air through it towards the tank

[billybek]

Another good reason to give up smoking!

[equality72521]

Originally Posted by billybek

Another good reason to give up smoking!

What?

[boyt911sc]

Damion,

Do what Don suggested. I was doing a start-up test for a friend's car after an engine installation. And this was exactly what we had, very high cold control pressure as high as the system pressure. The problem was blocked fuel return line. After correcting and fixing the return line, the car is now running without any hesitation at start.

Did you have any work done on the fuel line system before this happened? Like an engine removal and installation? Keep us posted.

Tony

[djb25]

Hi everyone,

Don was dead-on.

The screen in the WUR was filthy. I imagine this happened when I pulled the gas tank last fall to replace the front suspension pan.

I pulled the WUR and cleaned it out, the car is back to running and idling well.

Thanks everyone!

- Damion

[don gilbert]

if your tank has been sitting for a while, there is a 90 degree bend inside the tank where the return line goes in, fuel sitting there for a period of time will solidify. brake cleaner and a flexible rod (i used a piece of cable) will fi it

[djb25]

Don,

That's something I've never heard of before... fortunately, cleaning the WUR fixed my problem.

I definitely am going to have to purchase a new fuel filter, though.

Thanks again, everyone!

- Damion