1986 e28 520i misfiring and wont rev up PLS HELP!

[allistairh]

hi to all, just got my hands on a e28 520ithat needs a bit of sorting hope u can help me. i was driving along the other day on way to spares. and the car picked up a misfire. had just repaired alternator and was goin to get a new battery wen it occured, i thought it was caussed by the faulty battery as i had a good 1 in and the car was fine, replaced it but the problem is still there,checked and cleanded all plugs and leads but no luck. getting spark to all cylinders but engine still runs rough. seems to be on cyinder 5&6, the spark is purlpe in colour but i think it should be more blue? the car stalled and wen i started it up it would not rev up at all and back fires into the intake manifold? hope u guyz can help me with this as iam all out of ideas:cursin:. at the same time the fuel gauhe stoped working but the pumps are. thanks in advance

 

[zaleonardz]

If you open full throttle, is the problem still there... if so that possibly rules out a vacuum leak.

I would then suspect clogged/dirty injectors.

If not that, it could be a fuel pressure..ie fuel pump/regulator

 

[Bmw.wp]

check out www.mye28.com also. they maybe can help too.

 

[allistairh]

thanks for the help, problem still there but now car wont rev up... also i checked the wiring on injectors and both wires are pos and stay on the whole time and it doesnt seem to switch off as if its getting a signal?:dunno:

 

[rick540]

Have you checked the distributor rotor?

 

[bmw111]

not to sure if this will help my 525i did the same thing twice there is a air pipe that goes into the intake manifold shine a light in there it is sometimes prone to blow out just push it back, my car did the same also missfires and wouldnt rev up like i said i dont know what your engine looks like but the symptoms sound the same.
hope it helps.

 

[allistairh]

hi all, thanks for all the help, really appreciated! alas i had to pull the head off as everything else was fine.... cyl head gasket burnt thru cyls 5&6. gave it a skim, then bent a vavle had had to pull it off again! back on and shes sounding sweet except fo a littl knock that wasnt there b4. think i set the tappets too tight, how ever there is a silver lining to this bark cloud- discovered the engine had been swapped with a 2.7 from the 525e, no wonder she just wants to thro here arse around. thanks again :thumbsup: