540i juddering wen i kick it at low rev

[ace]

HI guys,

I own a 540i m sport 2000 model. recently just changed the fuel pump n relay.

Before it actually gave way, i had noticed the car would start shakin or judderin wen i slightly accelerate from low revs at 3rd gear. its like the fuel supply gets cut off or sumthn for a seconds together just before changing gears.

any idea wat could be wrong? it runs fine wen i accelerate uniformly.... it only happens wen i cruise at low revs and then accelerate slightly but progessively.

Could this have caused my pump to fail? the car has done about 80,000kms.....

thnx for the expert advice

Cheers

Ace

 

[ace]

guys....

any idea wat the problem could be? is it a gear problem?????

 

[94silverbullet]

have you tried checking the plugs, distributor?

 

[94silverbullet]

vaccum leak?

 

[wood_e]

You are probably right. You have a fuel delivery issue, as thats a reason why the engine cuts out. A vaccuum leak is a wise thought as it would make your car run lean, then to compensate it would run rich. I would check for vaccuum leaks, and also check your fuel pressure. Also check your computer codes, that may tell you if a sensor is faulty.

 

[ace]

checked fuel pressure, its fine.....vaccum leak im not sure? how do i check that? and where do i look for it??sensors are working fine....no probs at all.....

 

[ace]

need urgent help...540i juddering

I had posted a few days back regarding the chuggin of the 540i 2000 model.

Things just got from ok to bad!.....

yesterday wen i was out late nite during some hard drivin.....the check engine sign started blinkin......now its on permanently! dunno wat happened!.....

the engine does not respond as it used to.....now it seems to be misfiring.....it hestitated and there is power of loss at times.....thats only wen i drive it though....wen i rev it in neutral it responds fine.....

any idea wat it could be.....ive parked it home decided not to touch it...till i can find a solution.....mind !@#$ed at the moment!...

do let me know wat the prob cud be mates!!!

cheers

ace

 

[94silverbullet]

I had posted a few days back regarding the chuggin of the 540i 2000 model.

Things just got from ok to bad!.....

yesterday wen i was out late nite during some hard drivin.....the check engine sign started blinkin......now its on permanently! dunno wat happened!.....

the engine does not respond as it used to.....now it seems to be misfiring.....it hestitated and there is power of loss at times.....thats only wen i drive it though....wen i rev it in neutral it responds fine.....

any idea wat it could be.....ive parked it home decided not to touch it...till i can find a solution.....mind !@#$ed at the moment!...

do let me know wat the prob cud be mates!!!

cheers

ace

I'd read the codes.

Off the top of my head:

possibly clogged cat converters?

bad O2 sensors?

Plugs, plug wires?

 

[wood_e]

On some manufactures a blinking check engine light means clogged cat converters. I am not sure if BMW has that as well. Has your can been running overly rich?

 

[ace]

dont have cat convertors!!! took em out for extra juice.......no codes appearing on the dash either!! how do i access them codes? any idea?? gona take it to dealership soon....but if its nothin serious, dont wana spend a truck load at the dealership!

 

[wood_e]

Normally if it was a US spec car I would say take it to your local auto parts place and get the codes scanned for free (96 and up US spec cars have standardized diagnostic connectors).

I am unsure though if you can do that, since you're from the UAE. I'm not sure but there may be a post catalayic converter Oxygen sensor that is reading improperly if you took them out. Again, don't quote me on that, but if you DO have one it is probably reading improperly since there's no cat present.

Wow, all that from a guy who drives a Ford...