1st Gen R53 Cooper S Morning Hard Starts & Now, 1-3k RPM Hesitation/Yoyo/Hiccup

Hey guys, Would appreciate much anyone's take on some issues. Stock 02 R53 w/ brand new battery, new stock belt(old looked thin but was working well),new stock plugs(old plugs looked/worked fine), always filled w/ V-Power & no codes on Scangauge.

1. First symptom of failing to fire on 1st crank came months back, car just sat for about an hour. Since then, 1st morning starts are a struggle. 1st turns just crank & never catch; 2nds are brief cranks, engine catches, stumbles, dies. Successful cranks are between 3rd-6th tries. Once it fires, idle is always smooth. Succeeding starts of day are either instant or 2 tries. Ignored since performance wasn't affected.

2. New symptom of 1-3krpm hesitation on about 50%up throttle was noticed after my previous fill-up. No misfires, no codes, just hiccups & absence of any power if I foot the pedal halfwy down. Feels like fuel starvation. Gradual acceleration to 3k up is the only option. 3k up, it's power-rich! Tried tying the bpv 2 days ago, no cure. untying it felt better.

3. Tried a bottle of Shell's Blue Coral injector cleaner yesterday. Car warmed up same predictable way, same hesitation til I turned it off at operating temp. & instantly tried restarting to no avail. Car would catch briefly, stumble & die after many tries. Retried 3hrs later, car started on 2nd turn, perfect idle, hesitation still there. Took it for a spin to recharge the batt after all the cranking earlier. Might be coincidental to point injector cleaner as the cause. They seem to be more help than harm on our cars.

Hmm, I'm suspecting fuel filter or FPR on the hard start. I'm not so sure about the hesitation. Related? Car never dies when running, though, so I'm hoping it's not the pump. Having read so many threads on Yoyo to be tune related, I can't seem to reconcile why it just suddenly acquired the symptom w/o any tune change.

Sorry for the epic post, guys. Anyone had same experience? Hoping for any help. Thanks!

 

I always listen & let pump cycle 1st in all my cars before cranking. Those are the said symptoms even if its primed. Pump seems to be working fine, otherwise, I presume I'd never get it to start. Rail might just be empty after sitting awhile. Car is in pristine shape @ 45k mi. Never tracked, just enjoyed, religiously maintained & cared for.
Perhaps you might have a pic of that vac line, I'd really appreciate it, Paul. Intercooler should be off to access, right? Would that line cause both hard starts & yoyo?
Tip my hat to ya for how you've maintained Blimey! Been following since way back.
Thanks!

 

Thanks mucho, Nathan, you just beat me to checkin RealOEM. Anything I should watch out for in taking the intercooler off?

 

Would definitely be on that.:fingerscrossed: Keep you guys posted on hopefully positive results. Again, thanks!

 

Thanks for the great ideas, Paul. Sweaty palms just makes wrenching 10x harder, messier & longer. Just checking the bpv w/ zip tie took quite awhile. Haha. Will try tackling this later.

 

Update:
FPR Vac line 13 was in place. Car has been sitting, so decided to check if there is any pressure at all in the rail by pressing the schrader valve. Nothing, no pressure left. Hmm, checked the pump by priming it...pressed the valve again... PRESSURE. Put the IC back on & restarted the car...5 attempts before it fired up. Same old. Good to have eliminated 1 suspect.
So, FPR replacement next, guys? Couldn't find any how-tos w/ pics. Keith, I think had 1 way back, but pics have expired, if I recall right. Anyone? Thanks,guys!

 

FPR vac line 13 looks good, even like new, pliable w/o visible cracks. I"ll look closer. Off to ordering FPR w/ its 2 o-rings & injector o-rings then. How can line be separated from FPR bell housing? Just pull it off?
Appreciate the tips, Paul!

 

Absorbing everything! Really appreciate it! I"ll be attempting this when I get back from work-related trip. Updates then.:fingerscrossed:

 

I agree. I've filter on order,too, just in case. It's a messy job I probably cant avoid. 1 question, why do you think the rail wasn't pressurized @ all after sitting before pump primed it? Wouldn't that point more to FPR than filter? I'm planning to do these by elimination. The 2 OEM FPR o-rings might have to be ordered from Germany. Have you guys had any experience recycling back the said old o-ring?
Thanks guys!

 

Learning from every post! I shall heed all your advices & do them 1 by 1. Wires, filter & FPR, if necessary. Hmm, would be great to have a fuel pressure gauge permanently attached on the dash. To Paul, Nathan, Sneed & Keith, inputs are valued. Thanks!

 

Hey guys, back w/ a lil update. New OEM plug wires in, smoothened idle further, not that it was rough. Hard start/pre3k hiccup symptoms still persist. Turned engine off upon hitting oprating temp on scangauage, it struggles to restart, as it has been doing lately even before wire change. Though engine sounds way smoother & more reactive.
Vote for filter next? Hoping this gets finally resolved. Thanks!