BMW 318ci M43B19 hard to start issue + power loss.

[BMW318CI]

Dear All,

I am facing the mentioned issue above. The car randomly hesitate to fire up smoothly and also there is significant power loss at 4K rpm above. My mechanic suggested may be the fuel pump problem but i would like to seek more opinions first. Please help !

Ken

 

[kw930]

Have you done a scanning? Just base on symptom mentioned is very difficult to tell the root cause?
Other than fuel pump, it can be the ignition problem (coil plug or spark plug), which is quite common for E46.

 

[BMW318CI]

Hi kw930,

Sorry i haven't done any scanning. So far my dashboard has no warning signals on. I already crossed crankshaft positioning sensor out from the list because my RPM cluster is normal. The hard to start issue is random, sometimes it just fire up like a dream and one or few times will stall. I will check the air intake, spark plugs and coil plug as you mentioned. Just want to ask, what is the symptoms of failing fuel pump for e46 model?

 

[jarance]

Dear All,

I am facing the mentioned issue above. The car randomly hesitate to fire up smoothly and also there is significant power loss at 4K rpm above. My mechanic suggested may be the fuel pump problem but i would like to seek more opinions first. Please help !

Ken

1. Do you have problem starting when you leave the car overnight? - Sometime have to crank about 2 to 3 times but no problem after the car is started.
2. Do you sometime feel the car is hesitating when the fuel tank is below the quarter tank? (Like there is no petrol)

If YES, then you have fuel pump problem. To confirm, use special function test and choose menu "6" for the monitoring the Left and Right Fuel Tank level.

When Full, it will indicate "240330". When the Fuel Indicator show half tank, check the indication, it should show "000280".
It the first 3 digits show something, it mean that there are fuel in the left tank. This mean the fuel pump is not strong enough
to suck the fuel from the left tank to the right tank via the return fuel line (vacuum jet pump).

 

[BMW318CI]

1. Do you have problem starting when you leave the car overnight? - Sometime have to crank about 2 to 3 times but no problem after the car is started.
2. Do you sometime feel the car is hesitating when the fuel tank is below the quarter tank? (Like there is no petrol)

If YES, then you have fuel pump problem. To confirm, use special function test and choose menu "6" for the monitoring the Left and Right Fuel Tank level.

When Full, it will indicate "240330". When the Fuel Indicator show half tank, check the indication, it should show "000280".
It the first 3 digits show something, it mean that there are fuel in the left tank. This mean the fuel pump is not strong enough
to suck the fuel from the left tank to the right tank via the return fuel line (vacuum jet pump).

Hi Jarance, i will answer you one by one.

1.) Do you have problem starting when you leave the car overnight? - Sometime have to crank about 2 to 3 times but no problem after the car is started.
- Yes i did have difficulties in starting the car if leave it overnight. This car is weekend drive only so i typically leave it parked for 3 - 4 days. However sometimes it just fire up nicely eventhough it was parked for 3 - 4 days.

2. Do you sometime feel the car is hesitating when the fuel tank is below the quarter tank? (Like there is no petrol)
- Actually i can't really detect hesitation at all. I always pump half tank for this car, but right now its at quarter so let's see how.

How do i perform special function test as i do not possess any scan tool.

 

[jarance]

Instructions to access the hidden OBC functions:

• 1. Hold Trip Reset and then turning ignition key to on position ONLY (no need to crank the car)
• 2. OBC should show "Test" first.
• 3. Use Trip Reset push button and press 19 times until it display "19.0" that unlocks all the features
• 3. Wait for a few second and the 19 display to show "Off"
• 4 . When it show "Off", press the Trip Reset button until the digit show "6"

• Fuel Level sensor inputs in liters
• 6.0 109330+ Fuel level averaged; Left half sensor input=10.9 liters; Right sensor input=33.0 liters
• 6.1 0439+ Total tank level averaged; vlgs 6.0: 10.9+33.0=43.9 liters
• 6.2 0442+ Indicated value (44.2) and tank phase

 

[BMW318CI]

Instructions to access the hidden OBC functions:

• 1. Hold Trip Reset and then turning ignition key to on position ONLY (no need to crank the car)
• 2. OBC should show "Test" first.
• 3. Use Trip Reset push button and press 19 times until it display "19.0" that unlocks all the features
• 3. Wait for a few second and the 19 display to show "Off"
• 4 . When it show "Off", press the Trip Reset button until the digit show "6"

• Fuel Level sensor inputs in liters
• 6.0 109330+ Fuel level averaged; Left half sensor input=10.9 liters; Right sensor input=33.0 liters
• 6.1 0439+ Total tank level averaged; vlgs 6.0: 10.9+33.0=43.9 liters
• 6.2 0442+ Indicated value (44.2) and tank phase

Ok i will try that. So what readings i should look for if my fuel pump has problem.

And 1 more thing, although this may have nothing to do with the engine, my ODO mileage is now showing 999999 while the trip meter still running as usual. Do you happen to know what is it?

BTW, I booked a trip to my usual mechanic and he recommended to check for throttle body, spark plug and idle control valve first, as he said, start from the cheapest fixes. Hopefully things can be improved and solved.

 

[BMW318CI]

Guys, updated information

Last Saturday my mechanic changed the leaky vacuum hoses and 4 spark plugs. The engine now starts smoother by a margin and power delivery is much more smoother. The engine also vibrates less and much quiet. The thing is the idle of the car still runs abit lower that causes juddering when at stop lights. The idling RPM with A/C on now is about 850 rpm and with A/C off is about 650 RPM.

Please kindly advise my next steps ? My mechanic suggested cleaning the Idle Control Valve and Throttle Body.

But he mentioned there is gasket in between the throttle body and manifold might be broken if he taken it off. Is there such thing ?

 

[jarance]

Changing the manifold hose is cheap. Might as well change it since you are removing the throttle body and ICV for cleaning.

 

[BMW318CI]

Changing the manifold hose is cheap. Might as well change it since you are removing the throttle body and ICV for cleaning.

Do you mean the gasket i mentioned ? That manifold hose ? I don't mind changing to a new stuff.

 

[jarance]

Do you mean the gasket i mentioned ? That manifold hose ? I don't mind changing to a new stuff.

gasket is cheaper than the intake manifold hose.

 

[BMW318CI]

gasket is cheaper than the intake manifold hose.

Ok thanks, i will update the status here this coming saturday so i can share it everyone here with this issue.

 

[BMW318CI]

Dear all,

Just want to update drivers with M43B19 about my recent engine hard to start, low idling and performance loss issues. I have fitted silicone vacuum hoses to replace the stock one as they are damaged and leaking air, that's one of the reason for performance loss. We also discovered the MAF sensor may not reading properly, thus my exhaust has bit petrol smell and bubble when we full throttle it while parked. I will proceed with cleaning the MAF and idling control valves to see whether they solve engine issue, if not i will go for a half MAF and try again. Last but not least, engine hard to start issue is 80% related to fuel pump for my case, my car cranks and fire up quick but it also stall quickly. I have to give the car a few throttle to get it starting and once its stabilised or warm enough, any other engine starts through the day will be pretty much problem free. This coming Saturday i will proceed with fuel pump change, cleaning MAF and ICV and hopefully, this will cure my issues. Please stay tuned for my next update.

Thanks,

Ken

 

[BMW318CI]

Dear All,

So far i have changed new fuel pumps (there are 2 in my model), MAF sensor. The engine start up is much more consistent but still stalls occasionally. The only thing left to do is cleaning up the Idle control valve, which as far as i researched, can stalls the engine from time to time.

Total Damage:

Fuel Pumps + Labour = RM1890
MAF = RM90
Total: RM1980

 

[jarance]

Dear All,

So far i have changed new fuel pumps (there are 2 in my model), MAF sensor. The engine start up is much more consistent but still stalls occasionally. The only thing left to do is cleaning up the Idle control valve, which as far as i researched, can stalls the engine from time to time.

Total Damage:

Fuel Pumps + Labour = RM1890
MAF = RM90
Total: RM1980

Fuel Pump is expansive. Should have purchase just the pump only. I got mine from China for a fraction of the price.

MAF is very cheap. Sure that cheap.

 

[OldmanBM]

Dear All,

So far i have changed new fuel pumps (there are 2 in my model), MAF sensor. The engine start up is much more consistent but still stalls occasionally. The only thing left to do is cleaning up the Idle control valve, which as far as i researched, can stalls the engine from time to time.

Total Damage:

Fuel Pumps + Labour = RM1890
MAF = RM90
Total: RM1980

My comments: MAF Rm 90 may be cleaning of MAf ...too cheap for new replacement.
As for the stalling and or rough idling , my M43 ( ??) engine has a breather tube from the back of the valve cover which is connected to a round valve below the inlet manifold at the back. This valve does give you rough idle when cold and does periodically cause stalls, when its damaged. The is a soft membrane inside , just like baloon skin. On top of the valve, thereis a small hole at the edge. If its badly damaged, you can feel air from this hole. Worth to check this out as its cheap fix and this part is wear and tear part.

Attached pict of the breather valve: circled.

Hope this helps.

 

[BMW318CI]

My comments: MAF Rm 90 may be cleaning of MAf ...too cheap for new replacement.
As for the stalling and or rough idling , my M43 ( ??) engine has a breather tube from the back of the valve cover which is connected to a round valve below the inlet manifold at the back. This valve does give you rough idle when cold and does periodically cause stalls, when its damaged. The is a soft membrane inside , just like baloon skin. On top of the valve, thereis a small hole at the edge. If its badly damaged, you can feel air from this hole. Worth to check this out as its cheap fix and this part is wear and tear part.

Attached pict of the breather valve: circled.

Hope this helps.

Hi, MAF is from the junkyard, working well and solved my power loss by a big margin. Should had stated its a used unit.

Alright i will check that part out when i have the time. Thanks for the information.

 

[anakin]

Even from junkyard...the MAF is still too cheap...good for you bro.. :67:

 

[BMW318CI]

Dear Anakin,

The force is strong with you. The MAF price is some buddy at the junkyard that finds no use of it and wants to let go for a friend.

Update to all, i've finally solved the above issues. I've proceed with cleaning ICV, throttle body and replaced a faulty camshaft sensor. Now the car idle and sprint like a champ, engine is much quieter now and exhaust note is much bassy. Thank you for all that follow with my posts. Hope my journey can help solve drivers out there with similar issues.

Ken