1986 318i (m10) hard start when cold

[Etwenty1 45]

Have a 318i that cranks for about 5 seconds before it just catches then idles real low, when starting from cold. Sometimes needs a couple of cracks to get it going. When its warm or has been running it fires right up. Tried holding key at ign on for a few secs and that was better but still only just catches.

Have been thinking fuel and whether its holding pressure. I heard these have like a non return valve somewhere in the line ....? any hints?

Also the temp gauge only seems to work up to 1/4, even when the car is warm and the radiator hoses are hot to touch. All hoses are hot so water seems to be circulating. Is it the thema-time switch up on the top is faulty and how do you test those?

I have a bid on a haynes manual but it doesn't close till tomorrow

[nath 129]

Having been through the ringer with an M10 on my old E30:

-AAV (auxilliary air valve) check its operation by putting in freezer to check that it closes, and heating to check that it opens. It does not have full open to full closed travel ever, but can be adjusted to bias either way. Operated by way of bimetallic strip.

-AFM (airflow meter) make sure that it has not been tampered with and is in good condition inside etc.

-Distributor: make sure the timing has been set perfectly. Naturally the dizzy cap and rotor should be in good condition also.

-Throttle air bypass screw: This should be adjusted to a perfectly timed engine, to give correct idle speed when hot.

-5th cold start injector: can be tested by removing from manifold and when cold, cranking the starter with the injector going into a container. it should squirt only when cranking and no other time.

As far as I can remember, those are all that is involved in the jetronic starting. There may be more that I have forgoytten but I don't think so.

[Etwenty1 45]

Having been through the ringer with an M10 on my old E30:

-AAV (auxilliary air valve) check its operation by putting in freezer to check that it closes, and heating to check that it opens. It does not have full open to full closed travel ever, but can be adjusted to bias either way. Operated by way of bimetallic strip.

-AFM (airflow meter) make sure that it has not been tampered with and is in good condition inside etc.

-Distributor: make sure the timing has been set perfectly. Naturally the dizzy cap and rotor should be in good condition also.

-Throttle air bypass screw: This should be adjusted to a perfectly timed engine, to give correct idle speed when hot.

-5th cold start injector: can be tested by removing from manifold and when cold, cranking the starter with the injector going into a container. it should squirt only when cranking and no other time.

As far as I can remember, those are all that is involved in the jetronic starting. There may be more that I have forgoytten but I don't think so.

Cheers for that, do you know what the timing settings for timing light and flywheel method are?

[nath 129]

Ooh sorry no I dont, I remember reading it from the owners manual. The internet has confkicting info I feel. At the end of the day the best timing for mine was just when it 'felt' right.

My notes for you were ideal, as it is hard to actually have a perfect condition AFM etc

[Etwenty1 45]

So i found the distributor cap and rotor were badly corroded so those have been replaced producing a nice improvement.

The problem also was and is that the car is very slow to warm up. It took 30 minutes to get up to barely 1/4 on the gauge. All three hoses are hot/warm and so it the top of the radiator. The heater only blows luke warm.

I thought to replace the thermostat but it has one those thermovalves instead.

Any thoughts ? the car idles fine but throttle response is poor (yeah yeah i know its a 1800 auto thanks)

See my wanted to buy listing for a thermovalve is anyone has a good used one.

[CamB 48]

I thought to replace the thermostat but it has one those thermovalves instead.

This is the thermostat (#9) - are you sure you don't have one?:

http://bmwfans.info/parts/catalog/E30/2-do...at_water_hoses/

http://www.trademe.co.nz/motors/car-parts-...n-481975866.htm

Do you mean the auxiliary air valve thing - number 11 in this one - which bypasses air when the engine is cold?

http://bmwfans.info/parts/catalog/E30/2-do...ir_flow_sensor/

[Etwenty1 45]

This is the thermostat (#9) - are you sure you don't have one?:

http://bmwfans.info/parts/catalog/E30/2-do...at_water_hoses/

http://www.trademe.co.nz/motors/car-parts-...n-481975866.htm

Do you mean the auxiliary air valve thing - number 11 in this one - which bypasses air when the engine is cold?

http://bmwfans.info/parts/catalog/E30/2-do...ir_flow_sensor/

Yes part #9, most of the forum sites with info on this engine referred to it as a thermo valve.

Ah crap, just ordered the same thing new through a forum sponsor today for quite a bit more. Must be better quality.........

Tried to check the timing tonight but am unable to get either of the marks/symbols mentioned in Haynes to show through the peep hole. Only a thin rectangular tab. Do i aim to get this central on the port or is my timing so far off the real marks are not visible?

[nath 129]

Yes part #9, most of the forum sites with info on this engine referred to it as a thermo valve.

Ah crap, just ordered the same thing new through a forum sponsor today for quite a bit more. Must be better quality.........

Tried to check the timing tonight but am unable to get either of the marks/symbols mentioned in Haynes to show through the peep hole. Only a thin rectangular tab. Do i aim to get this central on the port or is my timing so far off the real marks are not visible?

The only thing that shows through the hole is that tab if I recall rightly.

[Etwenty1 45]

The only thing that shows through the hole is that tab if I recall rightly.

So how is it used to set timing? centre of the hole at a particular rpm?

[Etwenty1 45]

So how is it used to set timing? centre of the hole at a particular rpm?

After much googling this appears to be the view i have through the peep hole.

link