325i low idle speed

[sweep]

John you can hold the compresion guage then.

[StuBeeDoo]

Any news yet??

[sweep]

All compresions are just over 175 on the guage.all plugs were the same colour light brown slightly weak mixture.

[murran]

well that sounds fine.

sorry i wasnt able to come down, i got dragged to meadowhell insted.

[sweep]

A dodgy injector?

[StuBeeDoo]

Good news then.
If I were you, I'd be going over all that I did before the problem started with a fine-tooth comb before I start trying to work out what else could be causing it.

[sweep]

Im thinking now have i disturbed a injector?but all the plugs are the same colour.maybe get new ones.

[sweep]

Bump

[b17]

why not get your injectors cleaned? It will eliminate one possiblity

[sweep]

Injectors sent fot refurbing today.

[sweep]

Just fitted my refurbed injectors.car is much smoother but it is still ticking over low

[sweep]

Any more ideas on this one folks.. as well as the low idle speed when im rolling up to junctions the revs drop below the tickover speed and come back up !Could this be anything to do with the alternator voltage regulator?is there a idle control moduel on these?

[e30topless]

strange this.. even if 1 pot was down, the tickover shouldn't be so low,

have you tried another crank sensor ? easy to do a quick test Pete, leave the old sensor wiring in place coz it's fiddly to get it back right

bolt the new sensor in, route the wire over the dizzy, got to be worth a try, just a case of eliminating stuff

[sweep]

I will give it a go steve

[clipper]

Don't wish to sound stupid (but I will....) but why is this a problem ?

My 325i ticks over at about 600 rpm but it doesn't give me any trouble at all, except very ocasionally it will stall with the steering at full lock and the air con on.

I'd never considered it to be a major worry

[sweep]

I have tried a crank sensor today and its the same,when its running and i disconect the tps wiring plug the engine does not alter is this right?

[town325i]

No it should start to run dodgy as the ecu doesnt no where the butter fly is

[sweep]

Mine doesnt alter anything,

[TouringMatt]

Mate i've been in the exact same situ with mine for the past 5 years, never got to the bottom of it.

Recently changed all gaskets, brake servo hoses etc to eliminate air leaks, traced connections back to the ECU and checked voltages and readings and i have pretty much to same results as you.
Car idles at around 600rpm, only a touch higher from cold and never feels 100% right, like you say, another 100rpm would help smooth things out.

Have you ever checked the voltage at the idle control valve? Mine's never tied up with the figures in manuals. Its done my head in in the past trying to solve it, it usually ends up in me winding the throttle cable in a bit to cheat the idle speed, wrong i know but stalling out at junctions aint fun!

Matt

[sweep]

Yes i no tell me about it..minehas been doing it for around 4 months there must be a remedy to this.

[sweep]

Its been on a snap on diagnostics machine today and it came up with the air flow sensor(airflow metre) and its running lean so i have put a good known one on but its still the same

[TouringMatt]

That sounds a good machine, would be interesting to try mine on that

ECU reset?

Last time i disconnected/reset mine (throttle cable wound in) it idled cold at 1800rpm and warm 1200rpm, reset the linkage and reset the ECU and nope, 600rpm and stalling - twice today, so the cable cheat is back.

Often wander about my AFM, re-tract the arm ages ago when trying to solve another problem, but ive noticed the anti-tamper seal has sometime been removed so there is no way of knowing if its set right. From what ive read it only makes a difference at idle, once the TPS has switched.

Matt

[sweep]

It took a while to get into it but the snap on set up did it.is there a filter in the rocker cover which can be replaced?just wondering how it can be running lean with another air flow metre?

[b17]

Out of interest - how do you reset the ECU? Disconnect battery for 5 mins??

[StuBeeDoo]

Out of interest - how do you reset the ECU? Disconnect battery for 5 mins??

..... Then start the engine and let it idle for 15mins.

[sweep]

Im going to check the tappits next.

[sweep]

And no difference...any ideas with a last bump.

[davidt]

Have you checked the spark plugs it could be one of them is not working at low revs then clears as engine speed goes up.

[sweep]

I have put new plugs in it.

[sweep]

Now thinking of trying a fuel presure regulator

[e301988325i]

I have tried a crank sensor today and its the same,when its running and i disconect the tps wiring plug the engine does not alter is this right?

I'm sure that if the ECU was getting the idle signal from the TPS the engine does make a noticeable differrence.

just wondering how it can be running lean with another air flow metre?

they have to be adjusted to suit the car. . . on a gas analyser, idle by pass screw and internal spring tension on the black toothed whell, have to take the black cover off the top.

[sweep]

Now solved,i removed the throttle body again and set the butterfly with a 0015 feeler guage when closed and the reset the tps to work acordingly and its now idling spot on.....so now im back in love with the old girl..treats all round! thanks guys for all the help

[bpowell555]

Good man! When you say adjust the tps accordingly, what does that mean? Reckon mine has something similar as it idles low.

Btw, alternator voltage regulator / brush pack will give the power steering a bit more juice if its causing the revs to dive ...

[sweep]

Adjusting the tps acordingly..seen as i adjusted the butterfly with a 0015 feeler guage from completely shut this would activate the tps when at idle which would by giving the ecu the wrong signal so i adjusted the tps to activate from the butterflys new slightly open position.

[b17]

This is interesting...

...i adjusted the butterfly with a 0015 feeler guage from completely shut this would activate the tps when at idle which would by giving the ecu the wrong signal

Should the TPS be activated at idle? I thought that was the point...