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Z3 M BMW newbe with a fuel issue

559 Views 0 Replies 1 Participant Last post by  refacer
Hi, I'm Dave.
Sold my 04 Mazdaspeed MX5 (had it since new) and my 01 S2000 uber-turbo (completely and got me a 2001 z3 M roadster from a deceased surgeons wife locally. She has a 911 and a Benz crossover, and said she won't drive the M roadster because it would mess up her hair. Saw the add, and said "I'll sell the other cars later, but had to jump on this one. The price was right (less than I sold the 28k mile miata for) It certainly has been a love love love love -hate relationship. I love it more than any previous roadster I ever owned, but with 80k miles on it, it keeps giving me little problems I can fix, and a few I am not so sure of. I replaced the Rear shocks and RSMs, the brakes, rotors, oil and filter (I hope it goes 15k miles on that stuff! not a cheap oil change!! lol. Fuel pump, fuel filter, put in a remote door locks on the cheap (cost less than 30.00 with 2 remotes) I will post it later once I find out If it ever had a remote to begin with, because it does unlock ALL doors and trunk when you turn the key on any door). My goal is to put it back in great up to date level of maintenance. It looks great, and drives even better after I got rid of the squealing fuel pump and replaced the RSMs.

I don't know where to post my problem, so I'll put it here as well as in the Z3 section.

I'm a weekend mechanic with a bunch of tools, but not much BMW experience.
My 2001 bmw z3 M roadster will not start (right away) after sitting for even only 15minutes or so. I changed the fuel filter, and fuel pump assy. (500-1000 miles ago. it was making some sick groans on startup, and whirred verrry loudly always) when turning the key, the 5 second 'pre-pressurize' doesn't seem to be enough to pressurize the system. If I try 6 or 7 time it will sputter for a bit , then run. But if I hold the key in the starting position, but
do NOT press the clutch in, it will run the fuel pump for as long as I want, so I do that for 20 seconds, and it will start right up. I suspect a leak down of some sort (or does it always go pressureless when shut down?) , or a really weak fuel pump (it is no-name aftermarket, on the cheap side (78 bucks with adapters). I already failed with a denso, because it was nowhere near a "match" to the bmw, and came with no fitting kit. ($129.00). I replaced fuel pump gasket with new, put it in correctly (gasket first), and tightened unit down with the special wrench. Worked perfect for 1000 miles, now just won't start instantly like it used to. also went back and installed copper ring gasket on the filter at the regulator (OEM) I had forgotten the first time, and make sure there are no leaks I can see whatsoever.. again, does it always depressurize when shut down?

Is it time top pull the pump again? my car's tank is always full when this happens!

Thanks for putting up with me and I love reading all the stuff I find Here. AND I LOVE MY BMW. Finicky, but no worse than my wife of 30-odd years!