Fuel surging in 90' 318i E30

[CaseyM]

Can anyone help?

I am in Melbourne, Australia.

I have a 318i 90 model E30 Auto.
It has a fuel surg in all gears but prevelant at about 80 to 120k / hr.

The surging is smooth and constant.

We have tried and replaced/fixed/checked the following,
-injecters
-replaced plugs
-checked air flow metre

BMW machanic's can't work it out can anyone help?????

Thanks for your help.

best regards

Len Madin

 

[E30m42cab]

So does it idle high as well? (also, what engine are we talking about here? the M42, or the M40? I'm assuming the M40.)

 

[CaseyM]

E30 engine. Idling is normal. The only thing we haven't done at this stage is the CO. Mechanic is looking into it.

 

[E30m42cab]

I know your car is an E30, but what is your engine? M40 or M42?
M40 is a single overhead cam 1.8L 4cylinder, while there is also an M42 engine... a dual overhead cam 1.8L . I don't know what engine you have in Australia.

-You could have a vacuum leak somewhere, likely in the boot between the mass air flow sensor and the throttle body. They like to crack with age.

-Changed your fuel filter lately?

-Tried a new fuel pressure regulator?

-I have no idea what a CO is. Do you mean o2 (oxygen) sensor?

-Leaky intake mainfold gasket(s)?

Let us know!