Engine Chocking @ 4500 RPM untill I release the full throttle a bit with no torque!!

[grave77]

I have this E34 535i 90 model, I had this problem just last night my engine was always taking long time to start, and just yesterday after I started it .. it strated normaly and I stepped on the throttle to the MAX and it was ok ... I just went out of the side road to the main and suddenly it started chocking as if it's out of gas! then I went to the gas station and filled it with gas but no changes, I have replaced the spark plugs, air filter, gas filter, high-voltage coil, distributer cover and cleaned the injectors. non of the technicans was able to diagnose the fault. I need proffessional help.

[632 Regal]

could be fuel pump pressure, afm, a lot of things including O2 sensor. What codes do you get when you do the stomp test?

[grave77]

well AFM is ok I replaced a new one for test sake O2 sensor is disconnected and the catalytic converter too, it was working smoothly bfore without those 2 .. pump presure I cannot know ?! what test ur talking about can u clarify ( stomp ) ?!

[Jose]

had the same problem with my 535 2 weeks ago. I changed the fulepump which was making too much noise anyways and replaced the fuel pressure regulator on the injection rail. It's running smooth now. Check your vacuum hoses on your inlet manifold and on your pressure regulator for leaks.It shouldn't be your O2 sensor, the car will still go like if it fails, just the mpg gallon and the co2 level will go up. Just check your fuel pressure with a mano-meter before attempting anything else, an M30 engine just needs lots of fuel and air.....

[grave77]

U were right man !! ... fuel pumps brushes cover was broken and filpped so pump was working very slowly. I bought one from the scrapyard ... a full system pump and fuel level, and it worked like a charm. thanks guys