The built in check valve is bad in my old 535i's fuel pump, resulting in long cranking times. Otherwise, the fuel pump works well. Does anyone make a cheap in-line check valve. I hate to throw a $200 fuel pump on it for a $5 valve.
This should be a foot of new hose and 2 hose clamp fix.
Have you checked to see if the valve is available separately from the pump? Typically, on Bosch external pumps it screws in to the outlet on the pump. I know Volvo sells them.
IF you cannot find one, most boast supply houses sell 3/8 male barb'd valves pretty cheap. Last one I bought was ~11$ works better then I ever thought.
Streetwiseguy wrote:Have you checked to see if the valve is available separately from the pump? Typically, on Bosch external pumps it screws in to the outlet on the pump. I know Volvo sells them.
I'll look into it. I know the aftermarket pumps come this way, but I don't recall the stock one being serviceable.
When my S10 had a problem with fuel draining back I put a check valve in line.
I was able to order the check valve, and compression fittings from McMaster for about $30.
Off to check McMaster.
This whole condition could have been remedied if Motronic 1.0 primed the fuel pump when the key turns to 'on.' My new lawnmower does that. 
If I don't find a check valve I like, a momentary switch wired to the fuel pump relay will also work.
