E30 Zone

Dear All,

Need your help with a small problem i am having

My B25M20 was stalling when it was COLD when i started it, idle was a bit wavy, but once warm it was fine

Its already had blue and brown temps changed 3 months ago.

I thought id buy a second hand icv, put that in and it sorted the idle dramtically for a few days.....no waving of idle needle, no stalling when cold.

Now for some reason, when the car is cold, i crank the car and i have to pump and hold the gas pedal.....it struglles, shakes BUT DOESNT spit or band and then once say after 2 3 secs of holding gas its fine idling perfectly?!

What should i do or change, got no leaks or anything?

When starting from HOT, it starts instantiously, perfect idle. Car pulls well.

Thanks

Saboor

air flow meter!!!! im no mech but this happend to mine when cold, but it also was searching when idleing.

you think its the AFM, but the thing is it doesnt jerk or anything when im pelting or driving normally through traffic.

From what little i know, faulty AFM would mean i jerky ride no?

the symptons with my one was on a cold start it was noticeably slower starting then when hot it did not idle smoothly! so i got another afm and reset all the valve clearences and it was cured!! yours could be some thing simple like an airleak on the in take side of things!!

Yes defintetly, well i have a spare AFM, lucky i bought it atthe time of the ICV, though i didnt think Id need it.

Ok well do you think a KnN Cone is causingthe problems, someone said to me that my air/fuel mix could be off, as i dont have a cat, but i dont see how that can affect the cold start?

Saboor

Any other ideas people

UPDATE:

Well changed the AFM anyway, though i dont think mine had broken, but thought why not, it strugulled to start but then did kick into life pretty quick, quicker than before, though the engine was stark cold.

Went for a drive, and its pulling hard as ever........waiting for it to go cold and then will see what happens

Keep in mind that i still have the cone filter, cleaned the AFM with carb cleaner, so the air/fuel is still factory i assume.

The old AFM was ok, bit dirrty, but otherwise ok, engine was performing before the new(second hand) AFM went in, so no real noticable difference to me

Any other ideas guys

Saboor

UPDATE:

Car was stark cold in the morning today, and after changing the AFM and putting the KnN back on, it refused to start, had to give it a lot of gas pedal action before strugling to kick into life, but as usual, once it did start it was fine.

The idle is ever so slighlty wavy, everso slight, needle doesnt fluctuate but you can hear it, i have no air leaks

Any ideas guys?

don't think its your k&n I had a k&n with no problems, the hose from the AFM to throttle body had a tear in it as well and so I had a rough idle but it still started first time everytime whatever temp.

Snoops,

thanks for your reply.

From what i can see from the conditon of my boot, it looks new, no tears.

Also when i floor it through the gears, it pulls like a train.

Just whens it cold it just wont start...................

siddiqi1 wrote: Its already had blue and brown temps changed 3 months ago.

Although you have changed these two items , you may need to check that the wiring from the temp sender to ECU is good. Cant remember what the wire nop's are but im sure Brian Moore will be along shortly to tell you which wires to check.

HTH

lee

Ah ok, will do...well i dont know what to chekc exactly but when Brian does come along, Ill see what he says

Well, it might not be a spark/ecu fault, but just a fuel rail that doesn't pressurise correctly... Most M20's I've seen that haven't run for a while (week or two, no more) will struggle 5-10 seconds before starting on four and finally clearing their throats.

Now, does your fuel pump prime? (they don't all do) Is there a leak in the fuel system? Is the pressure regulator tired?

Again, these are only ideas...

Suzie,

thanks so much for the suggestions, much appreciated.

Fuel pump has never primed since theday i purchased it. This problem only started once i replaced the ICV, which did sort the cold idle, but then started this NON STARTING issue from cold.

I know that my old ICV was kaputt, as it started fine when cold but as soon as i gave it throttle and closed the throttle, the ICV would not kick in and the car would stall, however with the replaced ICV, it no longer stalls once it has fired!

I have been running my car very very low on petrol lately, but then i dont see how that would hinder its starting, because then that would also make the car hop and skip whilst driving, and the car operates perfectly when driving!

How do i test that the pressure reg. is knackred?

Saboor

Mate try doing your valve clearances, this sorted mine out. I had similar problems i.e poor idling/jerking. Once the valves were adjusted it ran like a dream. Theres an article on the zone, follow this link:

http://www.e30zone.net/modules.php?name ... echnva.htm

I don't expect it to be knackered, as you would splutter when driving normally. I was rather thinking along the lines of "doesn't allow the pressure to stay in the rail for a length of time".

My touring doesn't get much use at the moment, as constantly worked on and left unfinished, but when I go to start her up after a couple weeks, this is exactly what happens.

If you want to rule out the ICV from this matter, start the car with it disconnected. It will stay wide open. (if a 3 wire one. I've never had a two wire one, so can't tell you what those are doing)

Suzie,

ok i see where your going, could be reduced fuel pressure, will check this out....

Also, when i disconnect the ICV whilst the car is running, it affects the idle is no way, surely the car should try and stall no?

After even putting on all the electronics, heater, headlamps and what not, the idle hardly changes, but i knw for a fact that the throttle butterfly is fully closed, so how is it idling without an ICV???

thanks

Saboor

Delboy,

thanks for your post. Well it is due for an oilservice now, but i did have them adjusted only 4 months ago......that in itself was an ordeal, had to go back three times before it was right

But then is it possible you think forthem to suddenly jsut GO OUT?

Saboor

Change the fuel pressure regulator

Is it a hard job to do?

UPDATE:

Right so i changed the FUEL PRES REG. with a Bosch item, and still the problem prevails. Still wont start from stark cold, have to give a lot of gas and after shuddering all over the place it eventualy sits on idle perfectly.

New WORKING AFM, still no result
Tappets re adjusted, though they werent out much, no result
Rotor - was slightly burnt, cleaned it up no result (is being repalced tmrw)
Dizzy - fine
New alternator (not relevant) but jsut in case

I need your advise peeps, what next?

Saboor

topspark wrote: but im sure Brian Moore will be along shortly to tell you which wires to check.

No he won't, because he's at the Dingolfing BMW factory near Munich, where E30 tourings were made!
Back now though.
The Wiring in question is directly under the middle of the inlet manifold, assuming this is a six pot.
There's a round plug and socket fixed to the metalwork under the inlet manifold, that connects the injector loom to the engine loom. Water gets into it, lightly corrodes the pins, then fills the rubber boot of the lower part, where it rots right through the wires.
Has the throttle position switch been thoroughly been checked out?
The throttle should normally be closed when starting an E30. Shouldn't touch the pedal at all.

Brain,

Ive chekced the injector lom below the manifold, perfect, put some contact cleaner just in case but all is well in that dept buddy.

You say that the throttle should be closed upon start up, should it not have 0.015mm clearence, i do remebr reading it somewhere, or am i just chatiing jibber jabber?

Could it be my ICV?

Saboor

siddiqi1 wrote:.You say that the throttle should be closed upon start up,

Closed, as in foot off the accelerator pedal, so that the ECU is on the idle map.
Wouldn't think ICV would cause it not to start.

Ah well Brian when my foot is offff the pedal...........it will jsut turn over n over n splutter ando ver and over.

Then i let the starter rest, turn again , btw fott off the pedal, and over and over and then it starts and dies immediately

It only ever stays alive when i keep my foot on the gas, it like it needs to build pressure and then once it started its fine.

The odd occasion its spat and banged quite loud......but that was only once............i cant see it being the fuel del.:

Changed the Fuel Pump
Changed Coil too

Saboor

HT leads?

When mine does this, I change the plugs. They are getting oiled up at the moment though, so that might not be your problem.

Would be an interesting experiment to disconnect the two smaller leads from the battery + clamp, and connect them to a second 12 volt battery, so that the cars electronics is not affected by the battery's voltage drop when cranking.
A pair of decent jump leads to another battery would do the job.

Nope DaveD, they are perfect, when the car is driving, no problems what so ever, pulls like a train.

Today i changed the waterpump as it was leaking and changed the rotor, the dizzy was fine!!

Any more suggestions.

Im waiting for the car ot be stark cold for tmrw, then will see if any changes have occured.

My mech did say that the cambelt was quite loose, but its nice a tight now!!!

Sabs

Would be an interesting experiment to disconnect the two smaller leads from the battery + clamp, and connect them to a second 12 volt battery, so that the cars electronics is not affected by the battery's voltage drop when cranking.
A pair of decent jump leads to another battery would do the job.

thanks Brian for the suggestion, i will carry this out tmrw and see what goes, though i have brand new alternator and new bat, so dont see this resulting in much, but you are far more knowledgble than me so will give it a bang

siddiqi1 wrote: but you are far more knowledgble than me so will give it a bang

It's more 'clutching at straws' than knowledge.

siddiqi1 wrote:
My mech did say that the cambelt was quite loose, but its nice a tight now!!!

Sabs

I hope you mean that a new belt and tensioner has been fitted. It aint a good idea to tighten the tension on an old belt - that's just asking for bigger trouble.



Taylor.

Oh yes of course, new belt from BMW as well as tensioner!!!

Will report back guys tmrw morning to see the reuslts, will tick off the neighbours if i roar up my six pot atthis time of night

Did you get the CO set correctly at 1% after fitting the AFM?

the CO was set correctly,idles and hums perfectly!

Update:

Wel after leaving it overnight, i went to start it. Firstly aftr the first turn it sprang into life,but only to immediately stall. After the 2nd turn it startd,spluttered ever so lightly and then went on idling perfectly!

I have a sneaky suspicion that it might be my coil,what do you think guys?

Sabs

Nearly there then ? Read through the thread, have you cleaned out the throttle bodies with Carb cleaner as with all butterfles just about closed on "foot off" it doesn't take much crap to upset things.