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

Anyone tried the Walbro uprated pump kit that churns out higher pressure & discharge rate of 255lph? Any good? It's supposed to just fit into the VDO pump we have. It's half the cost of a new pump too. Just haven't seen an R53 how-to on this. Thanks!

 

UPDATE

Hey guys, my Walbro kit arrived today. Figured to finally have some light at the end of this very long tunnel.:wink:
Got everything ready for pump extraction & Walbro swapping. After getting the pump assembly out? Lo & behold! A TORN FLEXI TUBE on the outlet of pump. Uh oh, no replacement for this part w/ the kit. Scavenged my pile of junk in the garage & found an a yard long Gates fuel line, test fitted, & voila, just the right amount of tight + clamps.
Put the assembly right back into the fuel tank w/o swapping the Walbro yet. Cranked & it STAAAAAAARTED right up. I'm sure my fuel pressure now is way above 22psi. Idle was smooth, stepped on the pedal to look for my YOYO. Gladly, I couldn't find it. WOW, this one's for the X-Files. Anyone out there ever had their in-tank flexi tube turn brittle & break? Tank of gas was generally clean after 10 long years. Pump float arm a bit corroded but still works!
Since I had the adrenaline & momentum going, finished up my long overdue 1st stage fan resistor delete & jumped it w/ a long 12ga looped wire ziptied to the fan harness. Hid it on that bumper cavity under the LH headlamp. Tested the start/shut trigger temps. They were right on spec. Switched the A/C on, !st stage on HI came.
I just had no PS fan coming on at 1st stage since I have an 02 that wasn't rewired. Awhile back, I got tired of a randomly recurring sticking relay that kept my 2nd stage on when engine off. Had to line a relayed toggle kill switch for this & it worked perfectly.
For the PS fan, jumped a line to the + wire on that lil fan from my 2nd stage relay kill switch. Now, I can turn the fan on anytime before I'd get the 2nd stage w/c I now doubt will ever be called.
Why the doubt? Coz the resistor delete got me HI when Low is called. Engine is like 3.5F cooler, A/C cooler. The only downside to this mod is if your allergic to the loud fan noise.
Exhaled a huge sigh after all these today. I lost a yoyo, got a new Walbro spare pump I hopefully won't have any use for but gained a ton of new knowledge AND, found my old toy back. Can't curse nor complain.just THANKFUL!!!!What an adventure!
Thanks all for checkin' in. You guys have been my only refuge thru all this! M/A rocks!

 

Very possible cause for float arm corrosion as ethanol is hygroscopic. Well, it has been a decade old. I'm now strictly on vPower nitro+. Took it for a spin now. Just wow! Awesome response. I've forgotten how good it was. Just so relieved this episode finally concluded.

 

Update

Knowing the Gates fuel line that replaced the torn OEM pump tube was just an SAE 30r7, I didn't want to wait too long to replace it w/ hopefully a lifetime fix. Devised a metal tube coupled w/ SAE 30r10 end tubes to replace the 2 day old fix. True enough, lucky to have dug in the tank again. The 2day old tube submerged in petrol showed rapid deterioration. Pic would show bloating, permeation & it's now a soft tube. Imagine if that had stayed a few days longer.
Hope this will guide those who might have same problem.

 

Process would've been much shorter had I dared dig into the pump w/o waiting for the Walbro kit from the UK. Odd for something US-made to have a kit bundled elsewhere.
No regrets though as the parts I've replaced were all for regular & preventive maintenance anyway.
Good luck w/ you hunt. Hope it'll be just as simple as the hose.

 

Chances are I may be the only one to encounter a torn pump hose in the entire 1st gen population!

 

313k mi!!!! WOW! GRATS! Pressure regulator/anti-backflow should be on the pump side, I believe. The one on the rail serves more like a pulse regulator controlling rail pressure at the same time retaining some for start ups. If search points you to more questions than an answer, check the pump itself. Hope it gets sorted.

 

That should be expected as you've emptied the rails.
A friend called late last week seeking answers on exactly same symptoms as I had. His is an early 03R53. Told him my journey. He cut diagnostic corners & went straight digging into the in-tank pump hose. Oddly, same exact problem...A BRITTLED LEAKY HOSE. A swap cured the start & hesitation/misfire problems.
For those looking into this,though that hose comes w/ the VDO pump assembly, it can be swapped separately. Just make sure it's rated to be submersible. Gates 30R10 or equivalent should be good.
Guess our cars are starting to see new problems w/ age. That might only be the 2nd documented case. Hope ours will turn out to be random rather than some new found fault.

 

We're on the same page, Zip. e10 has caused nothing but trouble.