patchy acceleration

Hi Friends,another issue with my 1993 e34 525i.My car has not been touched since my last post as my mechanic is ill.Another problem I`ve had though,is that if I accelerate to over 4000rpm to overtake,my car responds though not as well as it should.But if I try to accelerate again I get no response and it seems to cruise and splutter for a while before it recovers.I dont get this problem at lower revs. thanks again.

There is another thread about similar problems here: http://www.bimmerfest.com/forums/sho...d.php?t=601970

My first thought on that thread was a fuel filter. Higher RPMs = higher demand for fuel at the fuel rail, therefore a restricted fuel flow would cause your symptoms. Do you have a CEL? Have you performed the stomp test? How are the spark plugs? Any other issues with the car currently?

Originally Posted by goosefoot33

There is another thread about similar problems here: http://www.bimmerfest.com/forums/sho...d.php?t=601970

My first thought on that thread was a fuel filter. Higher RPMs = higher demand for fuel at the fuel rail, therefore a restricted fuel flow would cause your symptoms. Do you have a CEL? Have you performed the stomp test? How are the spark plugs? Any other issues with the car currently?

Good list...Add a major vacuum leak as another cause.

Have a smoke test run if possible, or learn to smoke.

Hi paperplane94,thanks for your reply.my car ran fast and sharp for a year after I bought it,then problems started.I was getting sudden power loss at 5000rpm and self reving on idle.fitted new maf and lambda and had a full service.Things improved but it runs about 70% of what it used to.I only do about 4k miles per year at present because of these problems.some days its nearly back to normal then it runs rough again.No CEL and vacuum been checked.thanks

If you have confirmed 0 vacuum leaks with a smoke test the I would start checking things listed by Goosefoot33 above^.

Good luck!