Looking for some advice from the experts. I ran my '04 MCS JCW last weekend for about 100 miles including 40 on Sunday, no problems. Put it in the garage on Monday. Try to get it started on Saturday and it cranks but wouldn't start. I think its a bad battery (measured 11.8V with it connected after having cranked the starter motor a few times). Bought a new battery. Still no start after cranking a few times. Checked voltage on new battery and its also at 11.8V (ignition off, hatch open. Could the new battery have been so weak that the Mini wouldn't start?


I've got the new battery disconnected from the Mini and on a charger and will see if that helps. If that doesn't help, what else should I check?

 

Beginning to think I have a faulty fuel pump. Could not hear any pump noise when the ignition was turned on. Gave a thump to the fuel pump cover and then switched on the ignition. Heard an unusual vibrating sound like the pump binding up. Motor fired up for about a second before quitting.

 

Sounds like you're on the right track... any update?

 

Have you pulled the intercooler off and checked fuel pressure at the rail at key on engine off? Should have about 50 PSI. I would start there before you pull the fuel pump out.

 

I have seen more than a few times when individuals didn't inhibit any signs of a bad pump and then got a no start. After replacing the pump their issues were resolved. You could be on the right track for the fuel pump. You typically will hear it prime while in the vehicle. One symptom of failure is the pump getting stuck, and then finally kicking in after turning the ignition on and off a couple of times. After you do some diagnostic and determine it may be the pump we have them HERE and an article on the site to help you with the replacement if needed. Let us know what you find.

 

Update: It was the fuel pump. Replaced it and changed the fuel filter. Fuel filter change out took much longer than fuel pump. Engine runs real nice now and makes me wonder whether the old fuel pump and filter were restricting flow a little.


Only problem I'm now having is the "check filler cap" light comes on intermittently. I'm wondering whether I need to bang harder on the locking rings for the filter and pump to get them tighter.

 

Glad you solved the issue. If you've checked the basics and still are having issues with what may be causing the light then check out this thread HERE and HERE for some other options. They might be helpful.

 

Glad you have it fixed on the check filler cap light see here :MINI uses the same cap from 2002+

https://www.northamericanmotoring.co...or-a-week.html

 

Just thought I'd give a further update, hopefully to close out this chapter.


Recap - after the successful fuel filter and fuel pump replacement to get the Mini running again, the check gas cap light would illuminate intermittently, typically after making a highway speed run for several miles and for 5 or so minutes. Would typically get a whiff of gas in the cabin about the time the light would illuminate. Light would go out 5 to 10 miles later of around town driving.


Bought a new gas cap as the seal on the old original cap had cracks. Didn't think that would solve the problem but couldn't hurt to replace the 12 year old gas cap. As I suspected, it didn't fix the problem. Was still getting the light. So I pulled the back seat out again, opened up the access panels to the filter and fuel pump and banged on the locking rings' tabs clockwise with a punch and a mallet to turn them tighter. The filter ring turned probably another 1/8 turn, the fuel pump ring maybe a 1/16 turn. Without the special tool its hard to know how tight the rings are and how hard to hit the punch.


I think I was getting a little leakage from the filter side because it smelled like gas when I opened the access panel. Fuel pump side panel didn't smell. Have now run 75 miles with some highway runs with no Check Gas Cap light. Hopefully problem solved.

 

Glad you fixed it and lived to tell about it. Banging, fuel and punch are not three words that belong together!

 

Thanks. Let me add that I did take a few precautions. 1) battery disconnected, 2) I used a plastic dead blow hammer to strike the punch, 3) hatch, windows and sunroof all open, 4) a box fan aimed at the car to blow large quantities of air through it (basically like a bilge blower on a boat) and 5) time to allow any fumes to be blown out of the car before beginning work.

 

Thanks for the update. Happy to hear that all your problems are resolved now. Enjoy!