I've just bought a BMW 320i 1988it has the 6 cyl 2L engine, it is fuel injected. the problem is it is running a bit rough, black smoke, is hesitant when you rev it and has been using more than usual amount of fuel im told. it seems like a vacuum type problem or something as i've had a car that had a similar prob which was related to a split vac hose. is there anything, a common problem with these that causes this! cheers
attitudedesignz,
Feb 26, 3:57pm
Check the rubber pipe that goes to/from AFM. The have a tendency to get small cracks and create the problem you describe.
sas777,
Feb 26, 4:45pm
Agree with #2, and I would go further; strip out all the pipework between air cleaner and inlet manifold. Have a real good look for splits by gently flexing everything. Blow out the air cleaner. Also if it's fitted with an Air Bypass Valve (at 1988 not certain) get it tested. Then make sure throttle body is clean and adjusted to spec.
southern_man,
Mar 2, 1:48am
Hi there, thanks for the advice, so far i've checked the vac hoses for splits taken the throttle body apart and checked it, checked the AFM wich was clean as was the air filter, i forgot to mention previously the Check engine light is on on the dash. the car is still running very rich, lots of black smoke, but is running on all 6 cylinders. is there any way to tell what the error or check light is indicating without taking to a garage! Cheers
jmma,
Mar 2, 4:09am
Why would a mechanic diagnose it for nothing, can't feed the kids on Nothing
southern_man,
Mar 2, 4:24am
thanks for that, ill try removing the manifold and checking the gasket
elect70,
Mar 2, 5:52pm
Wouldnt leak on manifold cause a lean mixture as its past the TB , sounds like overfueling, cold start valve not stuck open !
paul756,
Mar 5, 12:48am
cold start valve especially if its running fine till it warms up allso the temp sender if its electricly controlled
southern_man,
Mar 5, 3:56pm
thanks for the replies, didnt realise they had a cold start valve, took the intake to bits and replaced the gaskets, still running rich, i did notice the thermostat is stuffed, the engine stays cold after a 10 minute run on the highway going to replace that today. roughly where is the cold start valve located on the engine anyone know!
lenoph,
Mar 5, 5:14pm
possible pcv valve! under inlet manifold
southern_man,
Mar 6, 12:08am
Yeah couldent find a valve under the manifold, do this model have a cold start valve, couldnt see one of them on the manifold either i see the older ones do.
southern_man,
Aug 7, 6:17pm
Tried the thermostat, how do you adjust the bypass it seems its a preset valve/ solenoid, i assume its the valve that bypasses the throttle body you are reffering to. also i found out that it may not have had a timing belt replaced yet, its done 130,000 kms not sure if this could effect low engine rpm or not
Since the public registrations are closed, you must have an invite from a current member to be able to register and post in this thread.
Have an account? Login here.