e36 M3 EVO running rough
Discussion
Recently put my M3 back on the road, oil service, brake fluid, and other bits were completed. Was running well but developed a misfire, advised it was likely a failing coil pack and so as these are original and 25 years old, I've replaced the lot with Bosch coil packs and NGK plugs at the same time.
Car is still misfiring. I don't have access to an OBDII tool.
Where do I go next? Could it be injectors? Can I remove and blow them out using a compressor?
Car is still misfiring. I don't have access to an OBDII tool.
Where do I go next? Could it be injectors? Can I remove and blow them out using a compressor?
stevieturbo said:
Origin Unknown said:
Where do I go next?
A mechanic ?You say back on the road...so did it run correctly before ? How long ago was that ?
And don't fire the parts cannon, it's dumb.
Had 50 miles or so of good running but started misfiring.
Year and a half not a long time really, shouldn't have needed much other than ensuring a good battery and turning the key.
Was it stored anywhere mice could be nibbling ?
Is the misfire there all the time ? or only some times ?
Check for good spark on all cylinders.
Check for fuel supply to all cylinders
You could do a compression test,
Was it stored anywhere mice could be nibbling ?
Is the misfire there all the time ? or only some times ?
Check for good spark on all cylinders.
Check for fuel supply to all cylinders
You could do a compression test,
stevieturbo said:
Year and a half not a long time really, shouldn't have needed much other than ensuring a good battery and turning the key.
Was it stored anywhere mice could be nibbling ?
Seen this many times, they like wires for some reason.Was it stored anywhere mice could be nibbling ?
parts dont fail on thier own, car parts dont have sell by dates, so it must have been something that has caused it, tbh if it was a mice inflicted wiring fault, while very possable, it would most likely shown up straight away. its most likely to be something fuel related, im assuming it had fuel in while stored, it does go off and block things and can eat away intank hoses etc. as it was ok for a bit my money would be a bit of gummed up fuel has made its way to an injector, best thing if first a fuel pressure check, by someone with the kit and knowlage, then if thats ok, injectors out and off for testing/ cleaning. but that is only a guess, take it to someone who knows what they are doing, and dont fire the parts cannon like you already have,
richhead said:
Seen this many times, they like wires for some reason.
parts dont fail on thier own, car parts dont have sell by dates, so it must have been something that has caused it, tbh if it was a mice inflicted wiring fault, while very possable, it would most likely shown up straight away. its most likely to be something fuel related, im assuming it had fuel in while stored, it does go off and block things and can eat away intank hoses etc. as it was ok for a bit my money would be a bit of gummed up fuel has made its way to an injector, best thing if first a fuel pressure check, by someone with the kit and knowlage, then if thats ok, injectors out and off for testing/ cleaning. but that is only a guess, take it to someone who knows what they are doing, and dont fire the parts cannon like you already have,
At only a year and a half, I wouldn't have any concerns about the fuel. I've had vehicles sit longer with no issues.parts dont fail on thier own, car parts dont have sell by dates, so it must have been something that has caused it, tbh if it was a mice inflicted wiring fault, while very possable, it would most likely shown up straight away. its most likely to be something fuel related, im assuming it had fuel in while stored, it does go off and block things and can eat away intank hoses etc. as it was ok for a bit my money would be a bit of gummed up fuel has made its way to an injector, best thing if first a fuel pressure check, by someone with the kit and knowlage, then if thats ok, injectors out and off for testing/ cleaning. but that is only a guess, take it to someone who knows what they are doing, and dont fire the parts cannon like you already have,
But really, some very basic checks could give info.
stevieturbo - grateful for your persistence.
Failed to get codes from the car, amazon 20 pin to 16 pin connect coupled to a Vgate iCar Pro that I already possessed and a free "Car Scanner" app... what could possibly go wrong. Connects to the Vgate thing but failed to actually connect to the ECU. Tried five times as the car was running with different profiles in the "Car Scanner" app. Car ran rough throughout but go up to temp.
I disconnect the cable from the OBD on the car, placed the cap on (this is an oldskool 20 pin OBD port under the bonnet), momentary dip in revs, and then the engine returned to normal running. No misfire, running fine on the drive. Make of that what you will.
I'll do a road test tomorrow and report back if the misfire returns.
Failed to get codes from the car, amazon 20 pin to 16 pin connect coupled to a Vgate iCar Pro that I already possessed and a free "Car Scanner" app... what could possibly go wrong. Connects to the Vgate thing but failed to actually connect to the ECU. Tried five times as the car was running with different profiles in the "Car Scanner" app. Car ran rough throughout but go up to temp.
I disconnect the cable from the OBD on the car, placed the cap on (this is an oldskool 20 pin OBD port under the bonnet), momentary dip in revs, and then the engine returned to normal running. No misfire, running fine on the drive. Make of that what you will.
I'll do a road test tomorrow and report back if the misfire returns.
Check for vac leaks, there’s a few ones which like to perish over time, mine had a cracked pipe under the inlet manifold letting unmetered air in.
You mentioned you serviced it, double check the rubber boots going from the air box to the inlet and that they are seated correctly. I’ve been guilty of not getting mine seated quite correctly.
You mentioned you serviced it, double check the rubber boots going from the air box to the inlet and that they are seated correctly. I’ve been guilty of not getting mine seated quite correctly.
VANOS does not operate within a big enough window to cause misfiring 
get a decent scanner on the car to monitior live data (misfire date especially) if its misfiring at idle or can be simulated whilst car stationary isolate each coil in turn to find the culprit cylinder i.e does unplugging suspect coil make bugger all difference or little
get a decent scanner on the car to monitior live data (misfire date especially) if its misfiring at idle or can be simulated whilst car stationary isolate each coil in turn to find the culprit cylinder i.e does unplugging suspect coil make bugger all difference or little Origin Unknown said:
It's booked in with a local BMW Indy who was happy to take it on. I cannot get a code reader to work with 20 pin OBMD converter and some of those free scanner tools so rather than guess my way through diag, better to get an expert.
Will update.
E36 is too old for most OBD scanners. You really need an ADS interface for the E36, but hard to find these days. Even BMW dealers will struggle these days.Will update.
Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff