Help!

[MrFrenic]

Hi Everyone.

Total Noob to the forum, so don't know anyone, so this is a shot in the dark.

Got an E36...... no.... come back... please!

I'm having a few bugs with it at the moment, and wondered if anyone can help?

1991 325i SE, M50 engine, str-6 24v

Took the whole exhaust off and replaced with Stainless, manifold through-out, there were 2 CATS, now there's none, just a centre box and back-box.

Got a K&N Panel filter to replace the std air filter, some new sparky's about 2000 mile ago.

Now, I understand the engine will need a little bit of a tune after removing the cats, but.......

Sometimes when accelerating, I'll gradually floor it and there's no response, until I get to almost full throttle, then it'll kick and go, as if fuel's being held, then released, it'll do this in all gears.

It grumbles unhappily at idle, wether its warm or not, it seems to be intermittent as it does clear itself up now and again and the car responds how it should, but then it'll come back and its lethargic again.

It's really buggin me as I've been caught out a few times whilst trying to pass something on the m-way and just lost all power.

Somebody said the plug coils may be goosed, but I'm not sure.....

Can Anyone Hep?!?!!

[ropeman]

Sell it and buy an e30 I reckon you may get a bit of stick posting an e36 problem on an e30 site


Fuel pump not keeping up with the increase of power would be my guess.

[MrFrenic]

I ain't trying to stir it up, just need help, if anyone can.......

We all own Beemer's anyway, its not like Ford V Vauxhall

Wondere'd about the fuel pump.

[ropeman]

I'm only having a friendly poke

Sounds like fuel starvation to me. As you up the bhp of any car it needs to deliver more fuel 9 x out of 10 your pump wont keep up so you have to fit an uprated one.

[Sooty]

I don't profess to know all the ins & outs of it, but if you've removed the cats, it's odds on that you will have removed the lambda (oxygen) sensor from the system as well.
If this is the case, then the ECU will be seeing a duff signal and will send your fuelling all to cock.
If it was running OK before your 'mods', then it's unlikely to be the plug coils.

[eko]

I don't profess to know all the ins & outs of it, but if you've removed the cats, it's odds on that you will have removed the lambda (oxygen) sensor from the system as well.
If this is the case, then the ECU will be seeing a duff signal and will send your fuelling all to c**k.
If it was running OK before your 'mods', then it's unlikely to be the plug coils.

Just the thing that came to my mind-again i`m no expert!

[PaddyR]

just chucking this in here, i aint got a clue about fuel injection, but on a bike if you change the exhaust and filter, you put in bigger carb jets to supply more fuel, you need something.

[E30BeemerLad]

sticking on an aftermarket system would be unlikely to result in fuel starvation IMO

I would agree with either the missing o2 sensor or sounds also like throttle position sensor, but more the o2 or lambda sensor as on wide open throttle it just opens the taps rather than doing the maths I think.

[Sooty]

You can get away with it on a bike because the air/fuel mixture is mechanically controlled by the carb.
With fuel injection, the mixture is governed/controlled by the ECU which is dependant on seeing certain signal voltages from various sensors.

HTH

Iain S

[e30cossie]

i have seen a problem on a few different cars with k&n panel filters .I think on some cars they let in too much air and the car does not know what to do with it.can you put a old standard filter back in to see if the problem stops.

[PaddyR]

Cheers Sooty, I never had a vehicle with an ECU before, now know a bit more about fuel injection.
my old XT-500 wont be happy

[jmc330i]

i have seen a problem on a few different cars with k&n panel filters .I think on some cars they let in too much air and the car does not know what to do with it.

An engine will only take in what air it can suck in, doesnt matter what air filter is in the way. My 325i is running fine with a large scale Brillo pad in the filter box (a non-soaped pad!)

lambda sensor as on wide open throttle it just opens the taps rather than doing the maths I think.

Thats right.


You could also try asking on E36coupe.com - they should be able to help more with an M50 question. Theres a couple people on here who may be able to help, but an E36 forum would be my first port of call TBH.

[MrFrenic]

Cheers for all your thoughts people

The Lambda sensor is still in place, the new exhaust system actually has a hole for it in the same position as it used to be, just before the centre box, (Was just before the cats).

The K&N air filter makes the tiniest bit of flow difference, but the problem doesn't change if its the K&N or the std air filter

Trying to get on to E36Coupe.com now, cheers for the advice all

Still gonna stick around on here, couple of me mates got E30's, Nice motor's

[jmc330i]

Still gonna stick around on here, couple of me mates got E30's, Nice motor's

Just a warning, stick around too long and soon you will be wanting to give that M50 a proper home, in an E30

[E30Mark]

Cheers for all your thoughts people

The Lambda sensor is still in place, the new exhaust system actually has a hole for it in the same position as it used to be, just before the centre box, (Was just before the cats).

The K&N air filter makes the tiniest bit of flow difference, but the problem doesn't change if its the K&N or the std air filter

Trying to get on to E36Coupe.com now, cheers for the advice all

Still gonna stick around on here, couple of me mates got E30's, Nice motor's

i don't confess to knowing much about CATS....

Personally i would try removing the lambda sensor and plug the hole, fit a resistor across the lambda connector.... i'm sure the guys on e36coupe will tell you what value, i seem to remeber 67Ohms from somewhere...

[Globulator]

Just some thoughts,

You may have damaged the lambda sensor in moving it
The K&N may be sucking in warm engine-bay air which may br misinterpreted as a warm day (deps. where sensor is)
It might be a totally unrelated fault caused by something else or something was disturbed/left diconnected
Deep down inside you know you need an E30 which is why you're inexplicably drawn to the zone

[tonyppe]

good advice on the lambda sensor, they are sensitive at times, you cant shout at them and tell them they look fat and to f-ing make the tea. fitting the correct resisor in series in the correct place will tell the ecu the reading is always perfect...
have you checked for air induction leaks? mine was doing what your describing but no where near as bad as what you say, mine had a split pipe.
also when you have to put your foot down, is there a lot of smoke that comes out the back? may be over fueling?
you could re-set the ECU (if you can do it on your car)
i do this by disconnecting the positive (+) from the battery and then turning lights on for about a min. then turning them off and replacing the lead, and starting the car like ive put a new chip in

[bmpaul]

alrght tony, its paul. i see youve taken the sale sticker out of your motor any luck dude?

[tonyppe]

hello mate, cor i found two friends today
well im keeping it now, after all the messers for eg. them people that call me up and i tell them everything about the car, they ask me if its a sport and i say NO, like i said, its a 318 with 325 running gear inc engine, brakes la la la. so they then come round to look at it, they get in and we go for a drive, they seem to like it, they then ask me again is it a sport, I SAY NO for the 2nd time, then i explain sports have black headlining, and he goes yer i know i used to have one... he then goes on, well i really want a sport and your car is not for me..
a bmw can be used as a good weapon. i should of run the little git over..

anyway, one of the for sale signs fell down, i ripped the other one out. blue tac is still there all prepped and ready lol
hows u and ur misses anyway?

[bmpaul]

fucking idiots!!!! we good mate just rolling along got me new motor (in my pic) good desision to keep her mate lovley car!!!

[MrFrenic]

Cheers for the comments guys,

The K&N is a replacement element, not a cone filter so there's no risk of sucking in warm air,
Haven't checked for air leaks, will do...
It does kick out some smoke when it's wellied a bit, whether cruising at good heat levels, or cold and just started
Dont think I can reset the ECU as easy as that, but I'll try!!

Cheers Guys

[tonyppe]

******* idiots!!!! we good mate just rolling along got me new motor (in my pic) "good desision to keep her, mate" lovley car!!!

its nice when blokes talk about their girlfriends this way isnt it

[tonyppe]

Cheers for the comments guys,

The K&N is a replacement element, not a cone filter so there's no risk of sucking in warm air,
Haven't checked for air leaks, will do...
It does kick out some smoke when it's wellied a bit, whether cruising at good heat levels, or cold and just started
Dont think I can reset the ECU as easy as that, but I'll try!!

Cheers Guys

well it shouldnt throw out smoke, how thick is it, i mean you have had ur cats off so there will be a little bit more, but its no diesel! or is it?

get some carb cleaner or brake cleaner or something like that, and with the engine running spray around all the connections to the induction. listen for changes in engine idle

[MrFrenic]

Its not that thick, it was best noticable late on at night, cool night, moisture in the air, it's hunting/surging on idle and there's big plumes coming out of the rear cans.

Its defo not Dis-iesel.

will try the carb cleaner when I get chance,

thanx