Exactly - there is non-return valve in the fuel pump, and the fuel pressure regulator closes when the engine stops. If one of those leaks, you lose fuel pressure over time and have longer initial starting times.

Got this from the BMW TIS for the MINI:

Description of operation: pressure retaining function
The pressure regulator closes when the engine is at a standstill and the ignition key is in position 0. The fuel pressure in the delivery line is retained over an extended period. A non-return valve closes in the fuel pump. These measures help to retain the fuel pressure in the fuel system. Extended starting times are thus avoided.

So the fix is usually either a new fuel pressure regulator or new fuel pump.

 

An update: I still had the extended start time issue after replacing the FPR. The car ran better though Interestingly, the problem was greatly exaggerated after sitting over night after a long 9 hour drive. That start the next morning took a lot of cranking.

I let the car sit a few days unused and checked to see if the fuel system still had pressure via the schaeder valve on the fuel injection rail. It was not pressurized at all. So, the problem is definitely fuel pressure related.

Then, I assumed it must be a bad non-return valve in the fuel pump. Replaced the fuel pump. Still have the problem.

So, I think I've finally (and hopefully!) narrowed it down to the in-tank delivery hose or maybe even the fuel filter gaskets. I don't think it's the actual delivery lines outside the fuel tank because I never smell gas fumes around the car. That leads me to believe the line is losing its pressure in the tank.

I think my problem is somewhere in this diagram (the fuel filter assembly):


I may try reseating the fuel filter, or just getting another fuel filter kit to see if that does it. Maybe there's a gasket that's not doing its job... The kit I used previously was not an OEM MINI one...

If that doesn't do it, I guess I would have to replace the entire fuel filter assembly (which is expensive!) to get new in-tank delivery lines.

Whatever the case, for now, I'm content to just prime the system a few times before starting...

 

For me the fuel pressure loss was in fact somewhere in the fuel filter assembly/hoses in the fuel tank. I replaced the entire thing and the car starts right up even after sitting for a while.

It was an unfortunate process of elimination - with both the FPR and fuel pump replaced, I knew it had to be somewhere in between...and it was.

Hope this helps those searching for a fix.

 

Correct my logic if it seems fuzzy, but being old school, it seems that if the fuel pressure regulator holds pressure in the fuel rail after shutdown, a bad fuel filter and lines or even a bad fuel pump would not effect the fuel rail as it has pressure held in it by the regulator! The car should start on the first crank! I would suspect a leaking injector letting the pressure out of the rail but I just installed a new FPR and have pressure at the Schrader valve after sitting all day. Still, a 6 second crank before starting. An inductive timing light shows I have immediate spark on the first crank. Is there a way to see if the injectors are firing on the first crank? Could it be that I have fuel, air and spark, but the injectors aren't firing immediately? This is frustrating and embarrassing, but, at 265,000 miles, I still love my '05 R53. It drew a nice crowd Nashville at MINI Takes The States. Any ideas?

 

There is also a non-return valve in the fuel pump, so it's a combination of the FPR and that non-return valve that keep the line pressurized when the engine is off. If there is a leak anywhere in between, such as through the fuel filter housing, you'll slowly lose pressure in the line with the car off and get extended start times.


Honestly, I can ask this question too. After I replaced the fuel filter assemble, fuel pump, and FPR, the problem went away, but now it's slowly and subtly creeping back. I suppose it's possible the lines in the fuel tank are losing pressure slowly again, but it seems unlikely since everything there is brand new.

With yours, does it require more cranking the longer it sits with the engine off? Or, if you turn the engine off, and then try to restart immediately, you still have to crank a long time?

 

If I restart within about 1/2 hour, cranking times are reasonable. I've had a rare few times when it fires right up, I think only when it is very cold outside. I guess if the lines themselves were empty, the FPR on the fuel rail would open the second it sees high vacuum from cranking and possibly dump that high pressure back into the lines instead of feeding the injectors? I thought about the vacuum line to the FPR. If it has cracked, I'm not opening the valve, but then, the pressure already stored in the rail should give me an immediate start, so, not logical. She doesn't even THINK about starting until after 6 seconds. I'll check that anyways and put a stethoscope on the injectors to see if I hear them clicking immediately. A vacuum gauge on the FPR line, fuel pressure gauge on the rail, and one on the fuel line before the FPR would tell the story. Not till this weekend though, back to work, another thousand miles.

 

Well, I was away for two weeks and tested for pressure in the fuel rail when I got back. Still pressure after two weeks of sitting unused - so all my fixes mentioned earlier in this thread are doing their job.

I suspect the longer crank times I have every now and then are due to the aging fuel injectors. Might replace them in a few years, but for now, I'll just deal with it...

Certain - if you have verified you have pressure in the fuel rail after the car sits for a day or two, my guess is your injectors are at least part of the problem, especially with 265,000 miles!

 

I read that you can put a stethoscope on the injector and hear it "clicking" to verify that it is functioning at least electronically. I've yet to do that as it is so hard to get to them with the intercooler in place. I started it without the intercooler once and it sounded like an air-raid siren. I guess even if they are triggering, it is no guarantee that they are squirting. Have you heard of a good way to test them? I will hit 270,000 miles this week on the original clutch. What a car!

 

Wow - that's amazing! I'm guessing it's gotta be mostly highway driving...

The method you mention of testing the injectors makes sense, but like you said, hearing a click doesn't mean gas is coming through. You figure the little plunger has moved millions of times and the internal spring is likely worn too in the injector. Who knows, maybe the solenoid is worn too.



You could see if a local junkyard has any injectors available - you might be able to get them for cheap, and they'll probably have 100k to 200k fewer miles on them than yours do!

 

Its pretty much down to injectors now. Maybe a shot of ether in the intake would tell me something if it fires right up; no fuel! Correct, mostly highway miles, it is my office. All business during the week, all joy on the weekends.

 

Wow - your office indeed!

 

Hey guys,


I have a similar issue...except mine takes two starts to start. I have only had the car for a month 2003 MCS...with 72k miles. I've just started dealing with colder weather, on the first start of the day it will fire but die immediately. If I restart immediately its fine.

When i turn the key I turn it to on to let the fuel pump prime before turning it over.

Any thoughts on what should be replaced? Spark plugs were just done.. Did not do the wires or coil. Thanks.

 

Since yours is starting, but then stalling, my guess is it's not a loss of fuel pressure in the delivery line when the car is off like it was for some of us on this thread.

I think I've run across some other threads with folks who have the problem you're describing. The fix might have been an ECU update, or resetting the engine adaptations...can't remember for sure what the conclusions of those threads were.