Hesitation and Bad Idle

Post Thu Mar 31, 2005 1:33 pm

This is more of a cure than a problem....

My car was jerky, keep trying to die on idle etc.

I replaced the rubber intake pipe between the airflow meter and throttle body.

It now drives like a new car, pulls much stronger, idles properly, when still rolling up to traffic lights, the idle stays around 1000rpm, then when you stop it slowly drops to ~700rpm as it should.

It's sweet as a nut.

This is just a 'warning' to others, that your running problem may not be electrical, try the intake pipe first, sometimes holes aren't obvious, it's worth taking the pipe off to have a proper check.

Now my car runs nicely. (apart from the fu**ed head!!)

Post Thu Mar 31, 2005 1:56 pm

It would seem that 9/10 times idle problems are due to this sort of fualt! I have told sam he should go and buy new pipes from BMW, even at wost it would eliminate them off the list!

Post Thu Mar 31, 2005 2:08 pm

lol dave, my clio idles wherever it wants, can be in the range of 400- 1300rpm. incredible really sometimes, but its a renault

also the clios are renowned to idle irratically so ive never bothered! tho i have checked throttle body hosing etc on this car and i cant see any problems. oww well itll be sold soon (hopefully)

its alot different with the e30 idling at 700rpm right on the nose! gives you a sense of precision, well to me anyway lol

Lee

Post Thu Mar 31, 2005 4:48 pm

just wondering, my car idles like a twat, ive changed the idle valve and no difference, i poured water & fairy liquid over that pipe thingy and didnt see any bubble, could there still be a leak??? please help as im thick when it comes to this sort of thing

cheers

Post Thu Mar 31, 2005 4:52 pm

Pouring water/fairly liquid may not bubble because it sucks air in rather than blows it out like a flat tyre.

All you need to do is pull the Idle Control Valve out, undo the two jubilee clips at each end....airflow meter and throttle body. Pull off the tube. Give it a bit of a bend in your hand to check for splits on the top/sides/underneath.

If you find any holes, renew it at BMW for about 13 quid.

When you refit it, make sure you get it on properly on both ends.

Be good if that is the problem!

Post Thu Mar 31, 2005 6:18 pm

Mate what hose is this on the M40 (1.

? You on about the big pipe leading from the inlet to the airfilter n stuff? lol

Post Thu Mar 31, 2005 6:34 pm

Yeah.

Sam, on yours it's the rubber pipe leading from the airflow meter to the inlet manifold/throttle body.

I think the part number on the M40 engine is:

13 71 1 709 754

Post Thu Mar 31, 2005 6:49 pm

Yup, that is the correct part number for a 318i (M40 engine) and often a cause of strange idling problems.

Only costs about Ãƒ”šÃ‚£15 from BMW.

While you're at it, take off the air flow meter, and give it a good clean with some carb & fuel cleaner spray, and check the air filter, or better still, simply get a new filter and use it.

Post Thu Mar 31, 2005 8:31 pm

Nice one guys.Well ive got a new ICV comming so i might order one of these tomorow as well.

What exactly is the Airflow meter Bharat? sorry for being stupid

but i know that the big pipe goes from the intake (right side of the engine) into the filter box, but between the filter and the pipe there is a metal thingy, is that what your on about?

this picture might help, btw if you look long enough it hurts your eyes, i think i should have picked some 'gentle' colours

Post Thu Mar 31, 2005 9:03 pm

Been messing with this on mine tonight!

That elbow looks cracked and has some splits but i cant see any that actually go through, i could however hear a brief, high pitched sucking noise when reving the engine so its getting replaced anyway

Also noticed that the IVC has a 99 manufacturing date, whilst the AFM has 84 on it

Cheers
Matt

Post Thu Mar 31, 2005 10:38 pm

Yeah, this hose was about 13 pounds including vat. Well worth it.

But as my head is fu**ed it's starting to overheat and stuff now.

You guessed correctly about the AFM Sam.

Its just measures how much air is going into the engine after the air filter and tells the ECU.

Can take it off no worries and give it a clean with carb cleaner.

Post Mon Apr 04, 2005 3:02 pm

Just went and got, and fitted a new Intake hose, Ãƒ”šÃ‚£13.It dosnt make any difference

Wasnt sure it it would as mine seemed in good nick anyway.Ive got a new ICV comming i think, so hopefully it will be that my old one is just a bit nackered.But seeing as it seems to settle down after long driving, would it be somthing else? I would imagen that the ICV would not function properly if it was cold,warm, driven, undriven or whatnot.

Guest · Post Mon Apr 04, 2005 3:23 pm

sorry to be a pest i have this problem with my car does anyone have a part No for this thing ???

Lars

Post Mon Apr 04, 2005 3:25 pm

There's a few different types Larcz, due to the ICV being T/L shaped and stuff. If you remove the old one, there should be a part number in small print on there.

Guest · Post Mon Apr 04, 2005 3:27 pm

thanks again mate you are a star its due to go in to a garage tomorrow to be looked at i will say to them about it ?

Lars

Post Mon Apr 04, 2005 3:39 pm

Cool.

You just have to undo two jubille clips one the throttle body end, and one to the airflow meter, pull out the Idle Control Valve, and then pull the rubber hose off.

My car is completely dead, but unrelated problems!