Idle Help(done all the usual) E30 320 Auto

I Have just brought a E30 3201SE 1990 with 49K yes only 49K on the clock, needs body work, accident door and bonnet.It will be up to show standard when finished. But......

I have an idle problem, iv read lots of threads here and other places and cant seem to find the answer. Mine idles at 900. Engage gear and it rose to 1K seems to high to me. That�s it, no back fire no rough idle, but it seems to much when slowing down (auto) on the brakes. Also the Fuel econ is crap!.

So I just fitted a new (�91) ICV and now its idles at 900 and when engaging gear it drops to 750 but still feels to high. Bearing in mind the mileage , my AFM is mint, there are no hose leaks. So what else, could the cold start injector be leaking making it run fast? Where is this and is it expensive (having blown my budget on a new ICV!!!)

Iv owned nearly all eighties BMWs Autos and manuals and this just does not feel right.

750 sounds about right, my old E30 320i auto had an idle problem (used to have to cover gas and brakes at the same time to keep the revs up otherwise it stalled when at standstill - then again the rotor arm was on its way out, and oil wsa dripping out of the induction kit)

The 320i isn't the best performer on the economy stakes, what sort of figures are you getting?

vpricey wrote: Ah dull one <SPAN =bold>tannerman8807, soz canni Help you on that one. Get on to E30zone and get Brian Mooooore to help you, he knowz Everything about E30's!!

I'm sorry, do you speak English at all? Idle speed on
an E30 320i (Motronic) should be around 750 rpm,
manual or auto. Since a 320i has neither a
switchable autobox or a cold start injector you need
to be looking at the TPS (throttle position switch) to
start with - if some clown has adjusted the idle
speed using the throttle stop screw on the throttle
body, the idle speed will be higher than usual (to
compensate for a shagged idle valve for example)
and it will also throw the TPS out. With the engine off,
open the throttle lever by hand and you should hear a
slight 'click'. This is correct and is the micro switch in
the TPS telling the ECU that the engine is off idle and
to increase the injector opening period. If you don't
hear a click, the micro switch will the activated even
at idle which leads to horrific mpg.
If you don't hear the click, wind the throttle stop screw
out until the click reappears and the idle speed will
be lower as a consequence.
Air leaks are always a favourite and the only way to
find one is to spray aerosol carb or brake cleaner
around all the joints and hoses, not forgetting the
inlet manifold gasket which is a favourite. Another
fave is the ECU which can go funny (or one of the
resistors inside can) and this can often be the result
of using an over energetic booster pack to get the
thing started. But the throttle stop screw is the best
place to start.

Ok M8 innit iv I speek 2 U in ur languidge p'raps U cn
unnertand me innit?

Are you perchance related to Ali G? As I am not
related to some illiterate text speaking cretin, please
do not address me as such. Thankyou.

"Is it cos I is black?"

Fuel economy could be down to your afm being so little used, try removing it and giving it a good shower in wd.

highidel, what about the throttle cable being out of adjustment, try removing the throttle rest screw, and seeing if the throttle backs off more (would need to remove the throttle cable to allow full movement for the throttle body.

remove the gubbins from the front of the throttle body, check yu don't have an oval shaped butterfly, and that is seating correctly. normally there is an air bypass, or a hold in the butterfly to allow air to still flo on idle, check this isn't enarged or blocked.

try a different ecu if you can get hold of one.

temperature sensors may affect this, google it, and check the resistance of each, car may be thinking its cold all the time.

thats my two sense!

chav and perfecto... cut it out!!! lol.

A tight throttle cable causes the same problem as a
maladjusted TPS. A dodgy temp sensor wouldn't
raise the idle speed but would cause heavy mpg and
all kinds of starting problems. I mentioned the ECU
earlier and would be worth swapping one over. AFM
is possible but use carb cleaner and an old
toothbrush to give it a good clean out.

The TPS costs nothing to sort out though. If you can't
get it to click, take off the throttle body, remove the
TPS, crack open the two halves and wash it out with
petrol or carb cleaner as they do fill with oil seeping
past the throttle shaft - leaving it soaking in in petrol
overnight gets all the oil and sh*t out. You can then
refit the TPS to the throttle body and set it up perfectly
- it should 'click' the instant the throttle is open.

Do this and see how you get on - I bet it'll solve your
problem.

What about a low idle? My 325 m20 continues to run low idle speed. very little hunting and no stalling. In drive, it idles at little over 500 rpm. No flatspots and it pulls like a train. So far checked / replaced:

Main temp sender the blue one

icv cleaned and it looks new anyway

Throttle body removed and cleaned

Throttle position sensor clicks as it should.

AFM stripped and cleaned. Measured readings and theres no spikes in the readings.

entire inlet side stripped off back to the head and ALL inlet manifold gaskets replaced (gen items) + the little rubber blanking tube on the bottom of the throttle body.

New Cam cover gasket

New breather pipe from the cam cover to throttle body

New oil filler cap

Valve clearances checked to ensure they are not too tight.

Things I'm thinking of now are the brown temp sensor (which I believe controls the fuel mixture via water temp?) or Possible brake servo leak although I've clamped off the pipe to it and it made no difference.

The car pulls like a f*****g train and burns very little oil. It's on 103k now and is silent. Just idles slow / rough. Smells slightly rich too but co reading is about 1.25% which I believe is within limits.

ANY IDEAS??? PLEEEEEAASSE It's driving me insane.

 

 

 

vpricey wrote: later on found it to be a rip in the bottom of the Rubber pipe from the AFM to the inlet manifold!! It was hidden down the botton of the pipe so was hard to spot, the hissing was a bit of a give away though!! Sorted now though, �14.41 for a new pipe from BMW, sorted!! Running like a wee sweetie now!!

It's been apart sooooooooooo many times now I'm sure I would have spotted it. However you could be right and it could have a hairline crack that I've missed. They are VERY prone to cracking. I think I'll check it again, or for �14.41 I may as well just get one as they are so prone to damage. Cheers for your help.