Ignition timing and proper idle...

[bigmuthatrucker]

Does anyone know the proper ignition timing for an M20 engine also what should it be idleing at? I have a timing light I just need to know so I can make sure it is in time.. Also the idle needs to be adjusted as at idle the check engine light comes on. It goes off if I give it a little gas so I just think the idle needs to be adjusted.. any help would be great.. Also if anyone has a scan of the bentley procedure to change the timing belt. I just dont have the extra cash right now to buy one
cheers
jim

[Blitzkrieg Bob]

Don't know what you'd adjust.

Probalby need a good tune up, since most of the Idle and speed are controlled by the DME.


Try this place for some guidance
http://www.bmwe34.net/

[bigmuthatrucker]

well I just replaced the spark plugs and ignition rotor.. Cant the ignition timing be adjusted???

[Blitzkrieg Bob]

it's all controlled by computer via sensors.

So your problems could be from dirty ICV, AFM, throttle body, and vacuum leaks.

[Zeuk in Oz]

Does anyone know the proper ignition timing for an M20 engine also what should it be idleing at? I have a timing light I just need to know so I can make sure it is in time.. Also the idle needs to be adjusted as at idle the check engine light comes on. It goes off if I give it a little gas so I just think the idle needs to be adjusted.. any help would be great.. Also if anyone has a scan of the bentley procedure to change the timing belt. I just dont have the extra cash right now to buy one
cheers
jim
My very limited understanding is that the timing is set when the timing belt is put on - everything at TDC. My understanding is that this is not adjustable.
Idle issues can be related to the oxygen sensor if it only happens when the engine is warm, or else air flow meter issues - you will need to wait for the learned to answer further.

[Blitzkrieg Bob]

changed?

[bigmuthatrucker]

so the distributer is not adjustable??

[Blitzkrieg Bob]

rotor is mounted on the cam, and the cap is mounted to the timing belt cover. Not much to adjust.

Check out the website I pointed to in my 1st reply, it has lots of tune up tips and stuff to help you get going.

Watch out for the mileage of your timing belt, if it is due to be replaced and breaks, the valves and pistons will hit.

[gmannino]

Timing is not adjustable and is controlled by the crankshaft position sensor mounted on the front of the engine. If you have problems look toward the Idle control valve. A bentley manual would be suggested for these problems and if you are gonna try to fix it yourself. Make sure you do a tune up to the car, you might notice that the idle will improve.

Salvage yard is a great place to buy perfectly working parts also. But make sure you inspect them to make sure they look to be in good condition.

[bigmuthatrucker]

Well I plan on replacing the timing belt and water pump soon as I have been doing maintence on it. Considering the condition I got the car in.. I figure pretty much nothing was done.. So I have to do the timing belt water pump and belts.. I have so far changed the oil and filter (synthetic) replaced the fan clutch new NGK spark plugs air filter Tranny filter new brakes front and back. Things I still need to do.. New drive shaft, timing belt and water pump and thrust arm bushings..

[gmannino]

timing belt is not too bad to replace on the m20. I did it twice. Should take about 2 hours to do, maybe a lil longer for the 1st time. Make sure you have a bentley tho.

[Robin-535im]

Timing is not adjustable and is controlled by the crankshaft position sensor mounted on the front of the engine.

The "one-per-rev" signal is given by the CPS, but the *timing* is set by the ECU to match the engine load, RPM, air & block temp, etc. The Chips people put in (ala EAT Chip) advance the timing in clever ways to improve power... hence why you need premium fuel. Newer cars advance the timing on a regular basis, then retard if it starts to knock... our cars don't have knock sensors (maybe post 92-93 do, I don't know about those "new" e34's) so the timing is a fixed equation of the factors mentioned above.

Best thing you can do is make sure all the sensors are in good working order (AFM, temp sensors and vacuum lines) and that the "actuators" are clean and working properly (ICV, throttle body, fuel injectors, ignition system). THEN if it still runs poorly, look to the computer... but that is rarely the issue.

HTH

- Robin