Help - E36 3.2 M3 - Misfire and cutting

[kish]

Hey guys

Pls shed some light on this for me

The car idles and sounds like she has a slight misfire. she does it now and again.

Some times misfires for a hile then it comes right. she also does not rev up completely , till about 5000rpm, not always.

i have discussed this on another thread, it has been on a machine, and does show a trouble code for the MAF.

can this cause this problem, the car never did this even with this trouble code.

Could the plugs do this, i have noticed that one or 2 plugs have some brown marks on the outside of the insulator, looks like its sparking through the insulator.

give me some advise if anyone has had the same experience

thanks

 

[STREETRACER]

Hey bud, plugs can do it, but the machine will pick up which cyl miss fires!
It sounds like crank pick up sensor to me! what machine did they use! get hold of some one with a AUTOBOSS machine!
They are very sensitive and accurate! Some machines does not detect all OBD2 errors!

 

[calypso]

Coil packs are probably on the way out.
But if your car is already throwing codes, shouldnt you get that fixed?

 

[StK]

I would try the MAF...try disconnecting it.If it runs better then you'll know for sure its the MAF...after all the diagnostics did show the MAF as a fault....

 

[kish]

Hey guys

I did some tests last night. ran the motor and then pulled out the coils one by one while it had the misfire, the no 3 was not firing. then i swapped the no 3 and no 2 coils, still missing on no 3. i think the plugs dead. have not yet swapped the plugs or tried new ones.

what do those plugs cost, where can i get them cheap? down here in centurion.

wonder if that will cause the car to hold back at 5000rpm?

 

[STREETRACER]

can be the plugs! but R1550 from agents! dont go aftermarket it will work you out more coz they are useless!

 

[kish]

I dont know about disconnecting the MAF.

Thats what i did, to think off it, the misfire started after i drove the car with the MAF disconnected.

Is there a possibility that it could have went into limp mode and then caused a misfire

or maybe it has a stored trouble code.

Whats you guys views?

Im gonna take it to have it cleared tonight

 

[jacques50]

Spark plugs no doubt, but also replace the supressors wich are leaking spark, they show white marks on the side of the rubber where the spark came through, part nr for supressors 12131404308. The coils seldom gives problems, it's almost always the supressors, but bmw won't tell you this, they'd rather sell you a coil. try these s/plugs BKR6EK

 

[Clownshoe]

Spark plugs no doubt, but also replace the supressors wich are leaking spark, they show white marks on the side of the rubber where the spark came through, part nr for supressors 12131404308. The coils seldom gives problems, it's almost always the supressors, but bmw won't tell you this, they'd rather sell you a coil. try these s/plugs BKR6EK

What are supressors?

 

[jacques50]

The rubber piece that connects the coil to the plug, the spark starts leaking through the rubber

 

[Clownshoe]

The rubber piece that connects the coil to the plug, the spark starts leaking through the rubber

You learn something new everyday.

 

[QikNish]

Greetings,

TPS - Throttle position sensor. Change it......... now.

Cheers.

______________________
BMTech
0o(ll)(ll)o0

 

[kish]

Hey guys, sorted out the misfire.

Followed streetracers advise and got someone with an AUTOBOSS machine.

By the way, there is an intake air temp sensor on the M3. its the one in the intake box, its the long black sensor.

the intake sensor wiring was a problem, engine was reading intake temp at -48deg.

the number 3 injector was also blocked. we used fuel line cleaner and in worked!

Only one problem left, she still holds back sometimes, seems like under load conditions, did this yesterday at around 2000rpm. once you leave the accelerator and then press again it revs up.

we tested the TPS it shows 0.34v when throttle is closed and 3.95v when fully open, this seems to be fine as far as i know.

anyone have any other sugestions that could help?

thanks

 

[kish]

Anyone?

 

[SDP]

See if you can put a fuel pressure gauge on the car and check it under load

 

[ClassicB]

If you had one injector blocked, i am sure the same dirt went through the others as well.

If your tank is about half full does it still do it?

(just wondering how much dirt is in your tank and lines)

any other codes come up, while on the Autoboss machine?

 

[STREETRACER]

Hey guys, sorted out the misfire.

Followed streetracers advise and got someone with an AUTOBOSS machine.

By the way, there is an intake air temp sensor on the M3. its the one in the intake box, its the long black sensor.

the intake sensor wiring was a problem, engine was reading intake temp at -48deg.

the number 3 injector was also blocked. we used fuel line cleaner and in worked!

Only one problem left, she still holds back sometimes, seems like under load conditions, did this yesterday at around 2000rpm. once you leave the accelerator and then press again it revs up.

we tested the TPS it shows 0.34v when throttle is closed and 3.95v when fully open, this seems to be fine as far as i know.

anyone have any other sugestions that could help?

thanks

I had a same type story on my brothers 325i you can keep your foot flat and it doest rev up and when you lift your foot and then it goes again! hes turned out to be the fuel pump relay..
What other errors or fault codes did the Autoboss pick up?
if it was crank pick up sensor the autoboss would have picked it up!

 

[kish]

@streetracer

It did not pick up any other engine trouble codes, the others were A/C solenoid and drivers steering airbag.

by the way i have noticed that the misfire caused by the injector comes and goes. would you advise me to remove it and have it cleaned or should i try to use fuel line cleaner again.

where is the fuel pump relay situated on the e36m3?

thanks

 

[STREETRACER]

in the fuse box in under the bonnet! cant say which one exactly of heart , will have to go and check!
but the relay will cause a miss on all the cylinders not just one..

I will put some fuel system cleaner in WINNS if possible and go smack it for a couple of KM's..
did you clean your MAF?

 

[kish]

Yes, cleaned MAF

still holds back sometimes

Damn i wish i can find the problem, she runs fine when hot