HELP idle

[525ikicker]

hi my m20 engine has a few start up and idle issues. one is at start up it takes a few seconds until it starts, and also when idling sometimes the engine fluxuates in rpm between 750 and 400 and it shakes the car. Recently i just did a tune up new plugs wires cap and rotor, and i have drove 7k miles so far and never replaced the fuel filter, So my question is what do i need to do? replace the fuel filter? or the pump? or is it much more simpler.


justin


90 525i m20 w/106k

[BillionPa]

well, start with the filter, and clean your idle control valve (does the m20 have one?)

you may be due for a new crank position sensor.

check the resistence of your ignition coil.

[E34-520iSE]

well, start with the filter, and clean your idle control valve (does the m20 have one?)

you may be due for a new crank position sensor.

check the resistence of your ignition coil.

I agree, plus clean & regap the spark plugs, check/replace the ignition leads, and check thoroughly for split hoses and vacuum leaks. Adjust the valvegear if noisy. When the engine is running & warmed up, you should only hear a quiet ticking noise from the whole engine.

HTH,

Shaun M

[525ikicker]

do u know what the resistance of the coil should be? and what the valves should be adjusted too? thanks for the response everyone
very helpful


justin

[E34-520iSE]

I set mine to 0.25mm just before the New Year, and all is well. Use the feeler guage between the eccentric adjuster and the valve stem - not the cam lobe end (if you see what I mean).

Ignition coil primary (pins 1- & 15+) = 0.50 k ohms +/- 10%
Ignition coil secondary (pin 15+ and centre tower) = 6.0 k ohms =/- 10%

HTH,

Shaun M

[Morgenster]

(does the m20 have one?)

I thought every single E34 except the ones with EML.

[E34-520iSE]

Yep, M20's have an idle control valve, though sometimes I wish they never....

Cheers,

Shaun M

[Ferret]

Check out your hoses as well, just to make sure none of your idle control stuff has a vaccuum leak... you might have accidentally disturbed something during your recent tune up.

[525ikicker]

thank u everyone for the information... i will check everything this upcoming weekend or sometime soon, ps what is the procedure for air bleeding the cooling system after putting a water pump in? do u open the highest hose? well thanks much


justin