help

[jonmcghee]

hi all have a e34 doing my head in runs fine when cold but when heats up to half way mark it splutters and backfires through intake and wount go above 2 1/2 thousand rpm.

any ideas?

thanks

new plugs fitted about 500 miles ago along with full service

[vping]

Sounds ignition related.

[632 Regal]

what car/engine/year?

[AngryPopTart]

Uhh, sounds more like it's overheating. When we first put the head back on my E34, the thing would eventually start running junky and it was due to an air-pocket somewhere in the system. Took forever to get rid of it.

I don't remember having a problem revving over 2k or anything like that, but the last time I had a car that would not rev over about 2500RPM without stumbling all over the place it turned out to be someone setting the plug gap way higher than the factory ignition(it was a points type distributor) could handle. Correcting the gap let the thing run flawlessly.

[SnakeyesTx]

Sounds to me like a clogged catalytic converter. Allows the motor to run a bit while its cold but when the catalyst and the gunk stuck in it heats up and expands, causes enough restriction to choke your motor. Easy way to find out is to loosen the exhaust pipe before the cat just a little and run it (it'll be a little loud). If the car drives fine with the exhaust flowing freely through the gap, then you've got your answer. If it still behaves the same way, then start checking your timing on the cams.

[mamilapon]

hi all have a e34 doing my head in runs fine when cold but when heats up to half way mark it splutters and backfires through intake and wount go above 2 1/2 thousand rpm.

any ideas?

thanks

new plugs fitted about 500 miles ago along with full service

02 sensor

[bigtallsam]

hi there,

its almost certainly a poorly ignition coil

my 525i did exactly the same a while back = started fine but once warmed up, even a little. trying to accelerate resulted in major juddering, hesitation and backfire through the intake manifold

regards

s