HELP! Mini won't start after doing carbon cleaning!
 

I finished the carbon cleaning yesterday and put the parts back on today. Went to start it. It cranks forever, but doesn't start.

A couple notes specific to my process:
- I never fully removed the manifold, but just pinned it back away from the ports, which gave me room enough to get in there to clean. The hose on the left was too tight to remove, and I had enough room, so I went for it. Because of that, I didn't remove the two assemblies under the manifold prior to working (and that's where I stopped in the instructions, so I'm pretty sure I never disconnected the throttle body wires.)
- The method I used to close the inside ports after cleaning the outside was to disconnect the spark plug wires, then crank the engine for a second then hit the on/off button to stop the cranking. I then went to check to see which valves were open. Took two attempts to get the insides closed.
- I scanned the computer and got P0100, P0108 and P113B. That all makes sense to me, since I cranked the engine with the airbox off and the sensor there disconnected. After clearing the codes (using EasyOBD II on my laptop) I no longer get codes, but the CEL light is still lit on the dash when the car is on.
- I had the battery disconnected for three days while I did this (other than when I cranked the engine over to close the inside valves on day two.)

Any ideas? I'm going to remove the damn manifold tomorrow to see if I might have knocked anything loose rotating the manifold backward or forgotten to plug anything back in. I did see the throttle body pressure change on my scanner when I cranked the engine, so I'm thinking those wires are connected. I appreciate any help. I'm running out of ideas (and battery power.)

* MINI DTC P0100 (0x277A) - Mass Air Flow or Volume 'A' Circuit
* MINI DTC P0108 (0x281A) - Manifold Absolute Pressure / Barometic Pressure Circuit High Input
* MINI DTC P113B (0x2B5A) -Mass Air Volume Flow 'A' Maximum Exceeded

If you still have a CEL, sounds like the ECU is still seeing a significant fault?
What scanner are you using?

Have you removed the spark plugs to determine if they are dirty?
When the dealer cleans the valves, it highly recommended to install new plugs.

That's a reading from the Manifold Absolute Pressure (MAP) sensor.

Grab a battery trickle charger; you'll need it after all the cold-cranking you've done.

- Erik

Thanks for the reply!!

It's an ELM 327 that connects to my laptop through USB. The software is EasyOBD II. I don't know why the CEL is staying lit but I'm not seeing codes. Maybe I'll borrow a hand-held reader from Advance Auto and try resetting with that.

But here's a question: what kind of fault would allow me to crank the engine, but not start it? If it was a serious issue, wouldn't the ECU just not allow me to crank?


I put new plugs in about a month ago.

I'm perplexed that it cranks but won't turn over. It's like it's not getting fuel.

Faults like physical timing not in sync, like camshaft to crankshaft position...
Ignition coil faults, or grounding issues...

No, the starter is not tied into the ECU's safety logic.

Checked fuel pressure?
Checked for spark on the plugs?

- Erik

When I cleaned my valves I made the mistake of leaning on the car with it in gear and turning it over backwards. This caused the cam chain tensioner to retract and the timing to skip teeth on the crank shaft. With the type of chain tensioner these have (non ratcheting) they absolutely can not be turned over backwards. Luckily I had purchased the cam timing tools before I cleaned my valves and was able to re-time it and was set. Is it possible that you inadvertently turned the engine over backwards and skipped the timing? This would cause the issue you are having. If so hopefully you didn't bend any valves. I would suggest checking the valve timing. I hope this helps.

Thanks again for the reply! I took a spark plug out and noticed some gunk on it (remember, they're only a month old.) I'm guessing that was a result of my cleaning the valves. Maybe the valves weren't as closed as I thought when I was cleaning. I cleaned all 4 plugs, but that didn't fix the problem.

I did check for spark and no issues there. I don't have a fuel pressure gauge. It got dark, so I had it towed. Hopefully, the fix won't cost more than having the cleaning done professionally. I hate when a DIY job costs me more than having it done by the pros!

Fingers crossed that's not what I did! But thanks for the reply. It really feels like a fuel issue at this point - though, why coincidentally, when I'm doing the valve cleaning... There are no codes being thrown at all now that everything's back together.

Correct; always replace plugs after a carbon cleaning.

Hopefully so, report back with a status update once you've found the problem at hand.

- Erik

As it turns out, I managed to gunk up the cylinders, maybe to the point where they weren't getting fuel. Mechanic used some solvent to clean them out, then cleaned the spark plugs, and we were good to go. Cost about $120 to have it diagnosed and fixed, and she's running well now.

I probably spent too long letting the carb cleaner soak in (over a couple hours at one point when I got distracted by a very attractive sandwich with a side of a nap) and probably had some leakage into the cylinder. I also took three days to do the task, because I got started later each day than I wanted to and ran out of sunlight. So, instead of having easy-to-clean out liquid mess, the carb cleaner had probably evaporated, and left gooey black muck in the cylinder.

So, for anyone reading this:
1) Do the job all at once.
2) Don't over do it with the carb cleaner.
3) Don't let the cleaner sit for more than ten or fifteen minutes at a time before scrubbing/scraping then blowing it out.
4) Make sure you're working on closed valves

Otherwise, don't be afraid of this just because I'm dumb. All in all, it wasn't a difficult task.

Oh, and thanks again for the pointers! It's much appreciated. Don't know what I'd do without NAM!

Wow, thanks for all the details! I'm sure this post will help many in the long run.

Oh, also $120 is not too bad...under the circumstances eh? :wink:

Compared to paying someone for the carbon cleaning, I still saved money overall (I confess to having some DIY projects that did not end in the black!) And it's worth it, either way. Between new plugs and the carbon cleaning, the car's got all its zip back now, and I'm my mileage will go up as well.

Old thread here but in the same boat as you are. Car will only crank. It ALMOST starts but then just...nothing. Gotta have it towed to a shop..

I just finished cleaning the carbon build up following the same write up.
Car started after a few minutes of rough turning over.
Seems fine however it feels like im not getting any boost.
Suggestions?
Thanks!

This happened to me as well.

I end up cleaning the carbon thru the spark plug hole on the top using the gun barrel cleaner tool and attach a paper towel at the end. You can get the tool from any Walmart.

Be careful not to leave the paper towel in the chamber though.

I know this thread is old but I thought my experience might help somebody.

I cleaned my valves with carb cleaner and various brushes. When I put it all back together it wouldn't start after many tries. I pulled the spark plugs and the cylinder had visible carb cleaner/fuel. Cleaned and dried it out and tried again with no starting. I repeated this a few times with no results and was ready to have it towed to a shop. It seemed to be flooding every time.
I finally tried pulling the fuse for the fuel pump (#20) and trying to start it. It stumbled and stuttered. Stuck the fuse back in and tried it... No go. Pulled it out and tried and it started to run very rough just on fuel present as it did I shoved the fuse in and it reved up in a cloud of smoke.

It's been good since. There must have been a decent amount of carb cleaner in there in spite of my best attempts to get it all out.

Eric

Just did the walnut shell cleaning on my son's 2009 S. Got her all put together and he tried to start it, Nothing. No turnover, no anything. The Car blacked out completely. IT kept the fob too. He let it sit for about five minutes and the Fob came out, so we tried again. We did disconnect the battery after he arced my ratchet on the starter. We checked all the fuses and they are all good.
ANY HELP WOULD BE AWESOME

Need to check all the fuses.