No idle and missfire until 4000rpm

[randomspeedfreak]

Right the m52 is on the road

however, amongst other things to sort, the main problem is the idle and bottom end of the rev range!

it starts first time every time, and from cold idle is okay, however if i come to a junction when warm the car will stall

the car missfires under normal warm driving, it runs on less than 6 cylinders, then, consistantly as the revs rise and it hits 4000-4500rpm it clears up and starts pulling properly with no missfiring

if i help it to idle a bit with the throttle then it can just about manage a very slow lumpy idle on its own

i can smell that its lean but what do you boys think it is? ive properly blanked off the nipple bit on the swan neck from the icv. today i swapped the icv over for another and encountered the same behaviour.

i have a noisy injector could this be the culprit?

i have yet to renew the gaskets on the bottom of the m50 inlet as i was told they dont often fail. ill order some of these in if you boys think these could be at fault

how can i test the signal to the icv? (if the icv was half open id get this behaviour right?)

[DanThe]

As long as the ICV moves it should be working fine. Shite running when warm is a common crank sensor issue

[E30BeemerLad]

make sure the injector plugs /rail are pushed well down onto the injectors and that they make good contact

[randomspeedfreak]

[quote="DanThe"]As long as the ICV moves it should be working fine. Shite running when warm is a common crank sensor issue[/quote

my crank sensor is pretty dogey. ive got another one on order.
cheers dan

[randomspeedfreak]

make sure the injector plugs /rail are pushed well down onto the injectors and that they make good contact

ill check tomorrow morning, thankyou mate

[randomspeedfreak]

okay ive still got this problem. new crank sensor in. canged the icv over and it made no difference.
the car smells lean and runs better when it is running richer i.e. from cold

is my next port of call air leaks?

or could it be the e36 temperature sensor?

would a sticky injector do this? one of mine is making a hell of a racket

[rich318i]

okay ive still got this problem. new crank sensor in. canged the icv over and it made no difference.
the car smells lean and runs better when it is running richer i.e. from cold

is my next port of call air leaks?

or could it be the e36 temperature sensor?

would a sticky injector do this? one of mine is making a hell of a racket

mate get it on a computer and see what fault codes pop up

[randomspeedfreak]

okay ive still got this problem. new crank sensor in. canged the icv over and it made no difference.
the car smells lean and runs better when it is running richer i.e. from cold

is my next port of call air leaks?

or could it be the e36 temperature sensor?

would a sticky injector do this? one of mine is making a hell of a racket

mate get it on a computer and see what fault codes pop up

best way of doin this? ive never used a computer to diagnose before! how exciting! haha

[randomspeedfreak]

just think could it be a lambda sensor? ive noticed the car runs fine for the first few minutes after switching it off (i.e. before the lambdas have heated up possibly?)

how should i test them? what ohms should be across which pins when?

having about 20 thoughts a day about torching the thing atm

[e301988325i]

Unplug the lambdas and see how it runs the car will use a default value in this situation. quite difficult to test them, you need to test their 1v output by heating with a blow torch, do not measure their resistance. Lambdas with a corectly working heater element should be up and running in under a minute.

[randomspeedfreak]

Unplug the lambdas and see how it runs the car will use a default value in this situation. quite difficult to test them, you need to test their 1v output by heating with a blow torch, do not measure their resistance. Lambdas with a corectly working heater element should be up and running in under a minute.

okay thankyou bro. ill unplug them out and see how it runs then.
do you think i could be onto something? i mean from the symptoms described any ideas?

[E30BeemerLad]

Have you got the lambdas plugged in correctly?

The lambda for the rear exhaust branch plugs into the connection on top of the engine nearest the front and the front exhaust branch plugs into the plug on top of the fuel rail nearest the rear of the engine. They run like cack if not correctly plugged in

[randomspeedfreak]

Have you got the lambdas plugged in correctly?

The lambda for the rear exhaust branch plugs into the connection on top of the engine nearest the front and the front exhaust branch plugs into the plug on top of the fuel rail nearest the rear of the engine. They run like cack if not correctly plugged in

i thought they only plugged in one way around?! quite possible ill check when i next see the car - its currently stranded at my mates after the bottom rad hose split.

£18.50 +vat from the stealers for a bit of rubber!

[e301988325i]

Unplug the lambdas and see how it runs the car will use a default value in this situation. quite difficult to test them, you need to test their 1v output by heating with a blow torch, do not measure their resistance. Lambdas with a corectly working heater element should be up and running in under a minute.

okay thankyou bro. ill unplug them out and see how it runs then.
do you think i could be onto something? i mean from the symptoms described any ideas?

Apologies for my spelling and grammar in that post, was in a rush.

I don't think lambdas, more likely: crank sensor, vanos, cam sensor?, one of the coil on plugs. I honestly can't think of a single instance of a faulty petrol injector. It's worth unplugging and swapping lambdas over for an easy test. They can be plugged in the wrong way around, which on Simons recent E36 24v thread caused odd things to happen.

[DanThe]

Ive had sticky injectors before a couple of times, both times it was 2.8 injectors that id taken from scrapyard cars or engines id bought that had sat for ages.
For the £60 it costs its worth having the injectors serviced anyway IMO, injectortune on here do the £60 discount price for zoners.

Crank and cam sensors on these are known to cause intermittent running problems without giving fault codes, the only downside is the genuine sensors are £££ and the non genuine are very poor quality

[rich318i]

pay the money and never cut corners on cheap parts

[randomspeedfreak]

pay the money and never cut corners on cheap parts

at which point did i not pay the money and cut the corner?

okay lads thanks for your input. ive just replaced the hose and drank some coolant again so the cars back.

ive unplugged the lambdas and swapped them over and although initially i thought it made a difference it infact dosent really change much that i can tell. the transition between being missfiring and running clearly is now a lot more gradual i think? which is weird. they were however the wrong way around before.

so ive got pretty much the same symptoms, from the 5 minutes ive just driven the car the missfire is still there.

whats my next bet? im sending the injectors to injectortune, they dont do discount if it isnt an e30 engine. still they make a hell of a racket so £81 well spent imo.

anything else i should do? im pretty sick of this now to be honest!

[DanThe]

Ive sent M52 injectors to them before and theres not been a problem
Did you tell them your an E30 zone member hence the reason your contacting them?

Have you tried a different MAF yet? Or tried with the MAF unplugged?

[randomspeedfreak]

Ive sent M52 injectors to them before and theres not been a problem
Did you tell them your an E30 zone member hence the reason your contacting them?

Have you tried a different MAF yet? Or tried with the MAF unplugged?

hes saying hes never offered a discount to zone members with non oem motors?

anyway ill send them off as soon as im paid

the car has been a little better with the lambdas the right way around.

with the maf removed the idle is a little better, but it is a little worse elsewhere in the rev range.

will a m52 7 series airbox fit the e30? there is a genuine maf with this box on ebay i could do with a proper box i have a pikey cone on atm


cheers,
matt

[randomspeedfreak]

if anyone can help me out with this it would be great. im really down about this now. the car is now consistantly missfiring below 3k. above it is usually alright, but occasionally it will throw a spanner in the works and missfire all the way up the rev range?

what the hell is going on?!

injectors are going off next week.

could it be the air temp sensor?

still no idling apart from when cold

[e301988325i]

have you at any point had your fault codes read by a garage or tech friend? You say you have an M50 manifold on an M52, is that actually the case, if so did you get it remapped?

[randomspeedfreak]

have you at any point had your fault codes read by a garage or tech friend? You say you have an M50 manifold on an M52, is that actually the case, if so did you get it remapped?

i havent had them read no, yes its an m50 mani, and no it hasnt been mapped.

should i order one of these then?

http://www.ebay.co.uk/itm/BMW-E36-3-Ser ... 2131wt_932

*edit it says e36 in the title but not the description whats that about? will it work? what does everyone use?

[DanThe]

You could try it, probably a rip off of carsoft. Its worth trying a different MAF IMO

[randomspeedfreak]

You could try it, probably a rip off of carsoft. Its worth trying a different MAF IMO

ok maf first with injectors then get the software out after that.

would it be worth getting a video up?

just noticed slight possible vanos rattle at 2k on part throtte

[Supafly]

have you taken the coils out and checked inside plus checked the plugs?
during my engine swap water somehow managed to get into the sparkplug area in 5 & 6 which caused a misfire

[randomspeedfreak]

have you taken the coils out and checked inside plus checked the plugs?
during my engine swap water somehow managed to get into the sparkplug area in 5 & 6 which caused a misfire

i havent since i put the engine in, plugs were changed when i did im going to my garage now ill ahve a look. its not a consistant missfire. although it has got worse again now!

cant wait for payday to get this sorted!

[randomspeedfreak]

been running better recently. much less missfiring but its still cutting out

put another maf in there just now.
no change at all its the same.

im plannig on torching it?

[randomspeedfreak]

just realised - should i have a temp sensor at the airbox end?

[randomspeedfreak]

right i sort of solved this one.... there was a leak between the throttle body and the manifold...

secondly i hadnt blanked off the vacum inlet on the botttom of the throttle body...

and finally i had a leak between the vacum for the fuel pressure regulator, and the manifold

im still getting a lumpy idle at around 600 - 1000rpm, and i still get an occasional missfire below 4000rpm.

i have no idea what this could be as ive checked and re checked for leaks

any thoughts?