'87 325ic Engine stuck below 2000 rpm

[irish]

My '87 Bimmer cranks fine and the engine runs smooth and quiet up to about 2000 rpm ... then it coughs and sputters. It will not go past 2000. It doesn't matter what gear or even if I am just sitting in neutral..... The power seems OK up to 50 mph (which is about as fast as it will go since that is right at 2000rpm) but i cannot push it past that ...the engine coughs and the car jerks....

Does anyone have an idea of the cause?... I have changed the air filter and put an additive in to make sure there was no watter inthe gas but no change....

Mike

[silversled]

based upon this post I would suspect a clogged fuel filter. The real to verify this is to let the car die under (non) normal operating conditions and then try to restart the engine right away. And don't stop trying to restart the engine every couple of minutes. That will tell you if it's your fuel filter...it might be clogging after a few minutes of use and then back pressure check valve in the fuel pump may come into play. I would replace the fuel filter first and see what happens...good luck

[irish]

Thanks - I will try the fuel filter. The engine actually never does die...it idles fine and always goes to 2000 rpm ok then starts to cough.... when I back off the throttle below 2000 it runs fine again.... but the fuel filter is cheap enough and easy enough to change .... hasn't been changed in a while .... so I will try that first thing.

Thanks

[irish]

Now here is something wierd.... when I drive the car every day ... the initial problem with the coughing at the 2000 rpm seems to go away ... the car had been setting up while I drove my motorcycle ... about a month ... it coughed and sputtered at 2000 rpm the first day I drove it ... the second day it would cough and sputter around 3000 rpm and afterthet it ran fine .... Until I let it sit for a day or two ... then I had the problem at 3000 rpm. If I let it sit several days I get the problem again at 2k rpm ... seeems like the car doesn't like to be neglected ...... is there a part that doesn't get lubricated when it sits a few days that could cause this problem?

Mike