So a few months ago I got this cool OBD reader and gives me a bunch of Freeze Frame data everytime a code is thrown. I have no idea if this info is useful for diagnosing my issue, but just curious if anyone can tell me whether this will help narrow the potential issues?

For historical purposes, I was having a lot of misfires for a couple weeks. My spark plug wires were all corroded (MINI was originally from Wisconsin), so I replaced them, and no more misfires for a couple of months. But I was having what seemed like a detonation issue when my engine was under load with AC on and at WOT. 104 Racing fuel made the problem nearly completely vanish.

Now I'm once again getting misfires. You can hear it during acceleration as a series of machine gun like sputtering. I might be getting misfires now rather than before because the heat has caused me to run the AC more than during the previous months.

Here's the Data. The first time I wrote the data I didn't realize there was more data on another screen so that's why it's limited on the first one.

P0301
Cylinder1 misfire detected
Fuel sys 1 ol drive
Fuel sys 2 cl fault
Calc load %27.06
Ect 199 (deg f)
Stft b1% 0.00


P0301
Cylinder 1 misfire detected
Fuel sys 1 ol drive
Fuel sys 2 cl fault
Calc load %100
Ect 194 (deg f)
Stft b1% 0.00
Ltft b1 -0.78
Map 47.84
Engine RPM 3643
Veh Speed 67MPH
Spark Adv 22.00
Iat 96 deg
Tps 41.96%



P0301
Cylinder 1 misfire detected
Fuel sys 1 ol drive
Fuel sys 2 cl fault
Calc load %100
Ect 201 (deg f)
Stft b1% 0.00
Ltft b1 -0.78
Map 47.54
Engine RPM 5504
Veh Speed 49MPH
Spark Adv 19.00
Iat 152 deg
Tps 46.67%

 

I've had the same problem in my 03 the last few years. Misfires and code p0301. I change the spark plugs and all is fine for 6 months or 8000 miles, then it come back. Plugs look fine. I am running 19% pulley and colder plugs. Have tried both IRIDIUM and MULTI-GROUND PLATINUM. Could be the lousy fuel and high temps we have here.

 

How many miles on the Mini?

Check spark plugs. Might want to move them around, like swap #1 and #3 and see if the issue moves.

Are the injectors OEM?

 

id say this is right on .... the heat and gas never help...

how old are you plugs?

 

6 months or 8000 miles


Sorry, you were asking Richard!

 

sounds like u may have a high ethanol content in your gas

 

ha ha yeah sorry shoulda been specific...

 

About 58,000 miles. I've had the car since 37,000 miles. I believe they are oem injectors. I'm thinking an overhaul is going to be necessary. I'll try the plug swap since that's easy to do. Thanks!


Yeah fine, just walk right in and Hijack my own thread!! Geesh.

For me I've got about 9 months on these new plugs--installed at Steves Auto Clinic--but that's about 20,000 miles of driving as well.

 

i had this issue and it turned out to be my screamin' demon coil was taking the dirt nap. put the oem back on and all is well . i think it woulda' been better if it had said #1 and #3 or whatever . then i woulda looked at the coil first but for some reason it only mentioned one cyl.

 

I would get some new plugs... I change mine about ever 8k

NGK IK22 heat range of 7 for you

 

Thanks Chris,

I had no idea that Spark plug should get changed so often--never had an issue with my '03 Cooper in 65,000 miles, lol.

I just did a ton of reading on the NGK IK22's per your recommendation, so I'll give that a shot. (Denso IK22's were the reason I got this MINI--it backed out and stripped cylinder #1's plug threads--so I think I'll be trying the NGK's.

Thanks!

Richard

 

your misfires are happening at lots of operating conditions (look at calculated load, this is how hard the engine is trying to work) two are at 100% but one is at 27% (seems like freeway cruise).

If it's a fueling issue, it will move with the injector. If it does, www.witchhunter.com will do incjetor cleaing and flow testing for $60 for all four shipped and turned around in a few days. (If you want some stockers to play with I have a set lying around).

Since you've had corrosion issues, take off the coil and clean out the plug connections on the inside of the sockets. Also, take the feed wire into it off, and look at the connectors there. But like the above poster stated, if it's coil related on the input or the coil, it would be two cyliders that misfire... A dirty contact for one cylinder could expain a coil problem happening on only one cylinder.

The 104 octane is to prevent knock is just masking issues. You either have carbon build up that's changing comression, creating hot spots, or crap in the injector pintels that are screwing with planned flow. Do you ever get a lean code with the knock and ping? (If it's bad and from the injectors, you'll get the code, as the A/F is way off, if it's carbon build up and hot spots, then it's got the right amount of gas, it's just firing off at the wrong time.

So, move the plugs around and see where the misfire goes. Same with the injectors. Either try the Sea-Foam or get a shop to do one of those "fuel injection cleaning services" where they run tons of nasty crap through the car to clean the injectors and burn off the carbon.

Some comments on Densos. I've given up on them. They sure are sweet when new, but the tip geometry changes. I don't think the conductor is large enough to take the heat out of the tip and it melts. This changes gap and geometry, and the voltage requrie to fire the plut.

I can lend you some injectors and a coil if you'd like (but with me up here, it would take a day or two to get the stuff to you). PM me if you want me to send the stuff to you!

Matt

 

So I got some NGK's like Tuls recommended and installed them today. Before the install I noticed that both my #1 and #3 spark plug wire connectors had a little bit of corrosion which surprised me because they were all cleaned up before I installed brand new spark plug wires.

After removing the plugs, definitely #1 and #3 plugs looked more rusted than #2 and #4. I numbered them for easy identification.

The new NGK's went in easily--I got over my fear of removing the plugs--and OMG, I'll be replacing my plugs every 8 to 10,000 miles I guess. What a difference.

No more stumbling at idle with the AC on. No more stuttering at WOT. No misfires with the AC on and in any gear.

I'll report back after a few hundred miles but already I can tell the difference.

Thanks Tuls and Dr. Obnxs

Richard

 

did you TQ them properly... I recommend 24 ft lbs..it works


glad it seems to have worked out

 

I put anti seize on the threads, then torqued them to 23 ft lbs. And cranked it a few times past the clicking. I plan to check it often. Although I can set my wrench to 24, I'm not sure if it's even accurate enough to differentiate between 1 pound?

Question --I put a generic extension on the spark plug socket and after the plug is torqued--when removing the extension it seems to come off leaving the socket on the plug. Is this normal? Should I be using a different extension to make this less frustrating? I reattached the extension then wiggled the socket a bit, and angling the extension against the walls as I lifted seemed to make it release without coming off--but was just wondering if this was a technique problem, or I need better tools?

Richard

 

while frustrating. What I've done is tried to use the better extensions in my tool box, and also I took out the foam stuff that holds the plug in the socket and cut a bunch of it away. In the past, I've also removed the foam, and used a bit of blue tape to keep the plug in place. It sucks, but that's the way it seems to be with the cheap tools that breed in the tool box in the dark of night.

Also when you do your plugs, check the gaps. I've had supposedly "pre-set" plug gaps vary all over the place! Just takes a second, and may actuall help a bit.

Matt

 

ussually what I do after TQing is put the wrench in the revers.. and then turn/wiggle it so it releases that's normal...

 

Y'all need a Stahlwille 1042 Tubular Spark Plug Spanner



See http://www.stahlwille-online.de/inde...etail&pid=8930

I know it says for VW/Audi but this is the tool my tech gave to me so I can change my plugs at home. I paid him $35 for it.

 

I suppose one end is either 1/2" or 3/8" for the Torque wrench? Is that basically an extension and plug socket all in one unit? Thanks!

Richard

 

It's 3/8". What great about this tool is those that have put in a cam and have had to relieve the spark plug tubes can fit this tool down in the tube. Most full sized sockets have to much wall material to get past the dent in the tube.

Plus the top is knurled so you can hand tighten the plugs and then come back with a TQ Wrench. Makes installs easier.

 

Just a little update. I should have left well enough alone. Car was running perfectly, and the plug wasn't loose---but I decided to torque it another pound--BAD IDEA. Just a half turn more, and it suddenly got loose. Uh oh.

Turn it some more by hand--and no friction at all. I pulled the socket out and half of the plug came out--the ceramic portion and the threads were sheared off.

Now I'm stranded 50 miles from home--wife is making the trek to come get me..not fun at all.

My engine guy has an extractor that he says will fix the problem--but not until tomorrow--so my MINI sits here in the shop. I suppose not a bad place to break a MINI, but still, it sucks big time.

 

but for me, I stay around 20 ft-lbs. I don't know if it's the early heads or not, but I had a plug blow out. I just do 20 and check every now and then. But then Tuls has done a heck of a lot more heads than I have!

But you got off lucky. If it had been the threads that had come out of the head, instead of the plug shearing, you'd be screwed to the tune of $400-$1100!

Matt

 

I think if I had torqued it to 24 from the very beginning I would have been ok--but torquing it to 23, then driving it, then letting it cool down, then torquing again wasn't a good idea.

Good thing I bought 3 sets of NGK's, lol. Course now I"ll be short one plug forever now.

Richard

 

the reason I use the TQ I do is from testing... 24 was where the plugs finally stoped lossening... everything before that they would eventually loosen up... boost is a PITA that way... and I know if the hold for me at 24 and all the boost I run.. they will be fine for you!

the best part is.. after I TQ them... the only time I check em is to see how they are wearing... not for TQ... kinda nice ot know they are good and solid

 

So what do you think then? I torqued the plug after it had been already set for 23 pounds and had been driven a few miles--engine was hot, then cooled. Then I retorqued--setting wrench to 24pounds, and it loosened barely half a turn more.

At what point do spark plugs shear off normally? at 24.5 pounds? at 25? How close to the limit of torquing the plugs are we when setting them to 24?

Probably not something that can be answered of course--just trying to figure out where the failure was--from trying to retorque the plug or because I set the limit too high in the first place?

Richard