So, I had my HPFP replaced by MINI last month (not sure if this is related). Yesterday (and again today) I noticed that when I downshifted and floored the gas pedal (raising the RPM's quickly and significantly), the car hesitates and hiccups/jerks. It never did this before the HPFP was replaced. It feels like it's not getting a steady gas flow when this happens. Only happens when I lay into it and floor the gas, raising the RPM's quickly.

Any ideas?

 

I had a similar issue that I posted a thread about somewhere on here. Carbon cleaning fixed my problem. Otherwise, I unfortunately would have no idea where to start. I didn't really get too many opinions on my thread.

 

Can you try to describe the sound? Does the exhaust also hesitate and make a sound that correlates with this issue? I agree with babysarah that this issue deals with carbon build up on the intake valves. To me, this sounds like predetonation/misfires due to carbon build-up.

 

How many miles? Year?

 

2011/57,000 miles

There is no sound when this happens. Just the feeling of the slight jerking motion.

One thing to remember is that this never happened before the high pressure fuel pump was replaced.

Either way, it's going into MINI on Tuesday.....we'll see what they say.

 

I've had this happen as well. I don't get any CEL so no codes to help diagnose. I brought my car to mini device last week for a strange starting issue. No issues leading up but one day doesn't start. It kept turning starter but engine wouldn't start. After about a half hour if finally started and no issues after. Been about two weeks and starting just fine. No CEL. I took it in anyway and on the way CEL comes on. Service said only codes were engine misfires. Thus far they could not duplicate starting issue. They aren't sure but blame issues on possible carbon build up. I told them I had the cylinder head with rebuilt valvetrain last year about 18,000 miles ago. They said it's still possible there's carbon build up. I had them check hpfp and they said it's still good, no issues. My car does have 103,000 miles now, but new cylinder head at 87,000. It never had carbon build up before. When they took of the head last hear they said it wasn't bad.
I'm not sure what else could be the issue if there's no carbon build up and hpfp is working well. I'm still trying to rule out carbon build up though..What else could it be?

 

So, I took my car in for scheduled maintenance (Vehicle Check, Oil, Front Brakes, Brake Fluid) and after they replaced the sprk plugs and did a full fuel system clean the jerking/hesitation could not be duplicated.

Problem appears to be gone. I've had the car back and have driven it hard and I cannot get the issue to happen again either.

All's well that ends well.....

 

Great news! Very possible that it was a spark plug issue. Lucky. Could've been worse. My carbon cleaning was $450.

 

Good tip on the spark plug.
MINI recommends changes every 100,000km
But I bet at least one plug would fail/foul before that.

babysarah,
out of curiosity, what is the mileage on your 2007 MCS?

 

Who are you calling a CAR JERK!

 

Mine just hit 58k. I did the plugs at 56k (thanks to a misfire code), but the carbon cleaning is what ultimately fixed my hesitation/jerking. The price makes you but the result makes you .

 

My car is out of warranty and also out of scheduled maintenance, so this trip was quite a bit pricey ($1,285) but, nothing is scheduled for at least the next year and a half to two years and Shermann is running like he just rolled off the lot.

I'm at 57,500 miles.....

 

Not sure what a "full vehicle check" is .. but for oil, front brakes, brake fluid, spark plugs, and fuel cleaner that you can get at a discount store for $9 .. all for $1250!? Sweet mother of pearl.

I might recommend you find yourself a local mechanic because everything you had done is just simple, basic, routine maintenance.

Oil? ~$100
Front Brakes? ~$200
Brake Fluid? ~$50
Spark Plugs? ~$150
Fuel Cleaner? ~$10 - I would do this on your own.

.. As long as Shermann is running smooth! Mine is out of warranty too, and I thought $450 out of pocket was bad, haha.

 

I actually had a few more things done than what I originally mentioned so that's why the price started to climb. I know it's a little more expensive at the dealer but they have such great service at Seattle MINI and they take great care of me (my friend, who is also my MA, works there) so I will continue to give them my business, which hopefully won't be for a while....lol

Full synthetic oil change: $70
Front Brakes: $280
Brake System Fluid Flush: $99
Carbon Microfilter: $100
Spark Plugs: $200
Full Fuel System Flush and clean: $150
Replaced Cracked Drive belt: $180
Replaced leaking tensioner seal ring: $165

 

I have a similar issue...

When my tune was engaged, I nailed it in low rpms (18psi) and it misfired. After that the engine wasn't idling right. I replaced the plugs with a colder temp. range and everything was good.

After a few hundred miles now I'm getting the misfire with heavy throttle/tune engaged and a huge black cloud of smoke appears after the misfire. Engine idle is fine.

I'm at 40k miles, so I'm assuming it's not carbon buildup. I'm leaning more towards coil pack or HPFP.

Any ideas?

 

Have a 2012 S, 49,500miles, was sputtering at heavy throttle starting from 40+mph, but more so in higher gears under heavy acceleration.

Called dealer, told them of the issue, and that I'd be dropping the car off and they can work on it whenever they have time; had no CEL or anything at that time. 5(5!!!) minutes later, sputtering turned in to a CEL and engine running at what felt like half power only, very rough idle, very rough at low speed.

Waiting to find out what the verdict is on the car. My mechanic (stopped getting serviced at the stealership once the maintenance ran out) said from what I described, sounds like a misfire, could be spark plugs or coil going bad.

Will update as I know more.

 

Based on the info you provided, I'm leaning towards the tune as the culprit. What is the source of your tune. Sounds like the fuel trims are not right in high-load situations. Big clouds of black smoke are the result of super rich fuel mixtures being expelled.

A failing HPFP tends to struggle to meet fuel delivery demands and causes a low Short Term FT and a generally lean condition which does not a black cloud make.

Failure to ignite the A/F mixture, or after-ignition (not the sweet kind like in a jet engine) can cause that smoke.

 

Igotboost try switching maps

I had a similar problem: 3-5K it would boost cut hard in higher gears. Changed spark plugs and little difference.

Remapped on 91 instead of 92 on stage 2 and it's fine now

 

Replace the fuel filter

 

Check it out, but I seriously doubt it's a fuel delivery issue.

 

So you don't think it's fuel delivery bc of the black smoke?

It's a Renntech tune. Renn just got back to me and said most likely coil packs or carbon buildup. Check coil packs first.

 

Correct. Either a fuel filter or fuel pump issue would result in insufficient fuel delivery. Even if the HPFP was erratic, fuel is injected after a regulator that sets the upper max for fuel pressure. Black smoke is 100% of the time excess fuel. Meaning you are misfiring meaning coil packs, plugs or a seriously f'ed ECU (almost no chance). The turbos heat is capable of auto igniting the rich fuel mixture even more so than a NA engine. Carbon buildup is always a possibility, too. Absorbs extra fuel. Doesn't allow for proper compression, combustion. Have the intake scoped.

 

Dealer just called, faulty coil pack and spark plugs. Nothing more.

All fixed. Reading other owners' issues, is there reason to be concerned of keeping the car long-term?

 

Glad to hear it went smoothly and we were right on target. If you keep the car maintained, it will be just fine. Everybody's experience varies but remember folks come to a forum when they have problems so sometimes it's not a good cross-section. Coil packs fail, hang in there and enjoy it.

 

reviving an old thread here, but wanted to add i was having this problem with our 2011 cooper. was getting a bunch of hesitation. engine light finally came on and i brought it to the dealer. they said the spark plugs were bad and they replaced them (car only has 29k miles). car was running good when i got it back but i didn't notice pretty quickly that there would still be the occasional hesitation/ misfire. but it was so infrequent i didn't bother bringing it back. with the weather getting colder the problem became dramatically more pronounced and finally the engine light came on again. this time they said the coil was bad and they replaced that along with the plugs again. so far it's running good.

i was confused / concerned that they only replaced one ignition coil, wondering if the coil for the other cylinders were also going to crap out. after seeing the comment about someone's coil "pack" being replaced i found the below video. i'm assuming the dealer must have meant the entire pack when they said coil.

https://www.youtube.com/watch?v=E9n_LKFwPHQ#t=18