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Hi everyone. First post here, but I've been to this forum often looking for solutions to a problem my Mini has been having on and off for the last couple thousand miles.
To preface, my car is a 2004 base Mini, automatic.
My CEL comes on intermittently. Whenever it comes on, it's always a cylinder misfire. A couple times it has been 3 and a couple times it's been 4. The CEL has never been flashing, only the steady yellow. I took it in to the Mini dealer and they cleared the code and drove it around about 50 miles and couldn't get the code to repop. They retorqued the spark plugs (which they claimed were a little loose) and told me not to worry about it.
Well about 200 miles later, the light came back on. My Mini was getting its safety check, so I figured I'd get Goodyear to give me their take on it. They said that the fuel injector pulse was bad (read: nonexistant) for cylinder 3. They also told me that 9 times out of 10 that means the ECU is bad.
I found a used one on eBay for $160 and the Mini dealership told me a reprogam costs $400. I can spare the $560, but I want to make sure it's the ECU before I drop that much cash. Is there a way I can bench test the ECU? I have access to lots of electronics and test gear (I work on C-130 avionics), but I don't have the faintest clue about how to go about this.
P.S. Other symptoms include a rough idle and a "jumpy" throttle at speeds below 10 MPH. These aren't constant, but they generally lead to the CEL illumination. No smoke, used oil wasn't contaminated with other fluids, etc. Doubt it's a bad head gasket or valve since the problem seems to jump around cylinders.
Before you plunk down the money, check all your ground points in the engine compartment (there are several). As far as advice goes, RPM Motorsport (Victoria, BC) have been terrifically helpful to me on ECU issues.
Hi everyone. First post here, but I've been to this forum often looking for solutions to a problem my Mini has been having on and off for the last couple thousand miles.
To preface, my car is a 2004 base Mini, automatic.
My CEL comes on intermittently. Whenever it comes on, it's always a cylinder misfire. A couple times it has been 3 and a couple times it's been 4. The CEL has never been flashing, only the steady yellow. I took it in to the Mini dealer and they cleared the code and drove it around about 50 miles and couldn't get the code to repop. They retorqued the spark plugs (which they claimed were a little loose) and told me not to worry about it.
Well about 200 miles later, the light came back on. My Mini was getting its safety check, so I figured I'd get Goodyear to give me their take on it. They said that the fuel injector pulse was bad (read: nonexistant) for cylinder 3. They also told me that 9 times out of 10 that means the ECU is bad.
I found a used one on eBay for $160 and the Mini dealership told me a reprogam costs $400. I can spare the $560, but I want to make sure it's the ECU before I drop that much cash. Is there a way I can bench test the ECU? I have access to lots of electronics and test gear (I work on C-130 avionics), but I don't have the faintest clue about how to go about this.
P.S. Other symptoms include a rough idle and a "jumpy" throttle at speeds below 10 MPH. These aren't constant, but they generally lead to the CEL illumination. No smoke, used oil wasn't contaminated with other fluids, etc. Doubt it's a bad head gasket or valve since the problem seems to jump around cylinders.
Any input?
I know it's a long shot but ever fix this ????
I'm having THESE EXACT symptoms and have been for awhile. But now my battery drains and cannot find the source , it randomly powered on my GPS system. I had ny taillights n headlights out and idk if tgat caused this or bad ecu also but I'd see my running lights in the front bumper flash every 10sec at like 1/2 brightness like it was constantly running a voltage check...
also even with a new battery , 2x checked and cleaned ground wires and mount points it NEVER gets above 13.6v EVER. I think i only seen 14.???v the very 1st few hours i put in this new battery...
I also had my traction control randomly turn off and not be able to turn it back on and the light stays illunated for a few restarts.
my car will sometimes runs perfect , starts perfect ect but occasionally very occasionally its rough on cold start , thriws that #3 missfire code and stuff just like op mentioned.
anyone anything I can do to know forsure if it's my ecu or maybe a bad alternator?? I have a new alternator just sitting on my shelf i will throw in to try but I'm not confident by anymeans that that I'd going to fix my issue and more current issues my cars experiencing..
also i dont remeber code numbers off hand but they cane back as cyl 3 missfire 90% of time , sometimes cyl 4 missfire , sometimes bad cam sensor code , some times a bad tmap code.. lol ALL those sensors are new or relatively new and oem sensors also. I mean theres a chance one could be bsd but id just assume it would be throwing a constant code for that specific code..I also put electric grease and in all my connections when I replaced the sensors as well as 2x checked the wiring as I did end up replace a few connectors as they wouldn't stay snapped shut or were abit loose so I replaced it just for safe measure.. alot of that got done while doing other modifications inhopes to rectify the issues I'd had for so long but nothing EVER did , though I'd think it did because it's so intermittent..lol this is gonna be a frustrating one I can tell.
mods are :
sprintex supercharger kit with 60mm pulley and vented drain plug 21psi , thumper tpr2 big valve head , ns1 street cam , sneed4speed Manifold fully hand ported , 2% light weight crank , obx 421 catless headers with hand ported flange , nvida exhaust ( pops but not obnoxiously, no popNcrack tune on this car ) , larger intercooler and upgraded boots , hand ported stock supercharger horn , 3in throttlebody , custom ordered full 3in intake with 6in velocity stack and cone filter setup for true coldair intake , screaming demon coilpack , nology hotwire sparkplug wires , brisk racing step colder silver sparkplugs , 550cc fuel injectors , Detroit tuned bypass valve , intercooler sprayer , flexi oil dipstick , m7 aerogel heat shield and custom intake heatshield , upgraded silicone coolant hoses , 190 degree thermostat and cooler fan setting , aluminum coolant reservoir , Aluminum power steering reservoir, oil catch can , custom tuned by adriancl
Last edited by MiniManAdam; Apr 13, 2022 at 10:56 PM.
NAM member adriancl has tuned quite a few of the Minis on this forum. He does this remotely by logging into a laptop attached to the OBDII port on your car. I believe that he could analyze your ECU and deduce whether or not that is your issue. I also believe that it would cost you a hella less than a different ECU plus programming from the dealer. It's worth a shot in my estimation.
P.S. What are the specific OBDII codes you're receiving?
Might be worth checking the coilpack? The pins on 3 and 4 can corrode leading to misfire and rough running. Whether this can effect the way the ecu controls fuel I don't know but worth a try if it's free
NAM member adriancl has tuned quite a few of the Minis on this forum. He does this remotely by logging into a laptop attached to the OBDII port on your car. I believe that he could analyze your ECU and deduce whether or not that is your issue. I also believe that it would cost you a hella less than a different ECU plus programming from the dealer. It's worth a shot in my estimation.
P.S. What are the specific OBDII codes you're receiving?
cannot remember off hand but cyl 3 , cyl 4 missfire , #1 tmap low or bad voltage aswll as #2 map sensor , I've gotten an 02 code occasionally, I've gotten a lean condition code , I've gotten a bad cam sensor code..lol very random stuff
all come up randomly and only ever 1x at a time but the car ALWAYS exhibits the exact same symptoms.
Last edited by MiniManAdam; Apr 13, 2022 at 11:07 PM.
Hi Adam, lot of Prefacelift ECU fail after 18 years of work.I replaced a lot in last 7 years.You must move to facelift ECU, because is strong buid and can't fail.
Look how it look prefacelift ECU.
