Fuel leak at cold start valve

[robertk]

Need some help with new fuel leak in my 1980 euro 528i. Seems to be right at the hose connection to the cold start valve. I just started the car for first time in months. Car runs perfectly, and yet this is no minor leak. I think it started after the cold start valve turned off. I don't think there is a hose leak, but might be. Anyone have this problem?
Thanks for any help. I love this car.

Robert Knowlton

[RandyM]

When the engine is cold, pop the hood and start. The leak location should be obvious. My cold start valve was leaking where the plastic and metal parts are joined. A generous dollop of 5 minute epoxy solved the problem. Note that I am a total cheapskate and a new valve is a far better and safer solution especially when you consider the implications of fuel dripping onto a hot engine.
P.S. As I recall, mine leaked only on startup when the valve was open. Maybe you need a new hose?

[RonDwyer]

fuel hoses are cheap insurance

[Mike W.]

fuel hoses are cheap insurance

Amen to that. And use good FI hose, BMW hose is cheap and excellent.

Robert, I haven't seen you here in years!

[T.Hanson]

I haven't seen most people here in months. Now I don't see, " General Conversation,"...
No offense, no complaints, no requests for cash I remember for years. I know, "Had to ask ?"
I attended the local Vintage Sports car club meeting. Median member age 70. Big discussion on ideas for increasing membership. I'm guessing not many 35 year old kids have fond memories of a 1957 Morgan to want to buy and race one.
How about a '78 - '81 BMW E12 ?
Are there six of us ? Screwing around insisting on working on them ourselves ? And now,... obviously not having much need to frequent the club house.
2017. Toot toot.

[robertk]

Hi Mike and everyone. It has been a while. After I sold my e12 M535 and moved to Cali I haven't been able to play with cars much. My euro 528i is still in Alabama where it sits long intervals.

I discovered that the fuel leak was not in the hose just short of the CSV, but rather in the short hose from the fuel rail to injector number 2. Fixed that, only to have a new leak in the hose just before the fuel filter. I've replaced this one before (effin ethanol in fuel!). Replaced that, and no more leaks (yet). But for some reason won't start. Cranks strong and seems like it just about wants to fire, but doesn't.

Any ideas? I've replaced hoses near the fuel pump and filter on all my cars and after cranking for a while they always start. It was running great yesterday except for the pouring of fuel trail behind me.

Robert

[RonDwyer]

First replace every fuel and vacuum hose on the car, you may not have residual pressure in the lines from a bad pressure regulator and or check valve. New fuel filter. New vapor lines help prevent the trunk smell.

[robertk]

This is a new one for me. After fixing first the injector 2 rail hose leak, and then the one in the rear just after the fuel filter, I can finally get the car to start but just barely--runs terribly rough (like running on 2-3 cylinders) and can't maintain an idle. Car ran perfectly, even with the fuel leaks, just dangerously. It's well tuned after a lot of work with a new (old) AFM and vacuum hoses last year. I mean it runs well.

So, I assume it is still a fuel delivery problem, but what from simply changing the hose after the fuel filter (new) would cause this problem. All I can say it was pouring gas out of that hose when still had pressure. When I came back to replace the hose, there wasn't a drop fuel left. So, do you think something like too much air in the system hurt either the fuel pump or fuel pressure regulator?

Thanks everyone.

robertk
'80 euro 528ia
'82 e12 based 633CSi

[Mike W.]

No, something else happened. It might take a minute or two, but the fuel system is self purging of air and neither the pump or the regulator would be damaged by it. Any chance you took off an intake runner to do it and dislodged a gasket?