'85 325e with M50NV
This is when the engine is completely cold. I start and drive with the gas held at a certain position for more than two or three seconds and it will hesitate/loose power. It does not lurch or surge. It just feels weak. I then push the gas pedal a litte more and with a slight delay I get an huge surge of power. An almost too extreme analagy would be that it is like driving a three cylinder and then all of a sudden a turbo kicks in. This all continues for about 15 to 20 seconds and goes away once it is warm.
The idle when I first start is good and smooth at about 900 rpm. After about 5 minutes it goes to a surging idle, and then once it is all the way up to temp, it idles kind of rough with the occasional rough patch here and there.
It use to cut out at high rpm when I first got it running. There is also no power when I hook up a peak tool to the diagnostic port. However I can measure power at the port.
This is what I have done so far:
New coils and bosch regular dual electrode spark plugs
New vacuum hoses, intake bellows, o rings, and extra hose clamps
Cleaned ICV
New Intake manifold gaskets
New main fuel pump
New Oxygen sensor, continuity was okay
New water temp sensor
I tried a new air temp sensor (not an oe one), I don't have it installed currently, but it didn't seem to work.
Visually inspected cam position sensor
Visually inspected crank sensor
Tried another 403 ecu
Tried another MAF
Throttle position sensor was replaced by po
Things I need to check:
The dipstick isn't mounted very well. However, if I pull the dipstick the idle still goes up. So I am sceptical that this is causing a big enough vacuum leak.
I don't know anymore. Maybe we wired something wrong, or there is a short somewhere. I can go ahead and start checking continuity in other places, I just don't know what it should be for a lot of the sensors.
Thanks
Here is a pic for fun. This is before the new coils and other things.
This is when the engine is completely cold. I start and drive with the gas held at a certain position for more than two or three seconds and it will hesitate/loose power. It does not lurch or surge. It just feels weak. I then push the gas pedal a litte more and with a slight delay I get an huge surge of power. An almost too extreme analagy would be that it is like driving a three cylinder and then all of a sudden a turbo kicks in. This all continues for about 15 to 20 seconds and goes away once it is warm.
The idle when I first start is good and smooth at about 900 rpm. After about 5 minutes it goes to a surging idle, and then once it is all the way up to temp, it idles kind of rough with the occasional rough patch here and there.
It use to cut out at high rpm when I first got it running. There is also no power when I hook up a peak tool to the diagnostic port. However I can measure power at the port.
This is what I have done so far:
New coils and bosch regular dual electrode spark plugs
New vacuum hoses, intake bellows, o rings, and extra hose clamps
Cleaned ICV
New Intake manifold gaskets
New main fuel pump
New Oxygen sensor, continuity was okay
New water temp sensor
I tried a new air temp sensor (not an oe one), I don't have it installed currently, but it didn't seem to work.
Visually inspected cam position sensor
Visually inspected crank sensor
Tried another 403 ecu
Tried another MAF
Throttle position sensor was replaced by po
Things I need to check:
The dipstick isn't mounted very well. However, if I pull the dipstick the idle still goes up. So I am sceptical that this is causing a big enough vacuum leak.
I don't know anymore. Maybe we wired something wrong, or there is a short somewhere. I can go ahead and start checking continuity in other places, I just don't know what it should be for a lot of the sensors.
Thanks
Here is a pic for fun. This is before the new coils and other things.

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