E34 engine loses power @ 4500 RPM
Engine runs strong til 4500 RPM, then power fades abruptly.
Running thru the gears (5 Speed Man. Trans), engine runs superbly, then at 4500 it hits a wall. What has been replaced in the last year; new fuel pump, fuel pres regulator, oxygen sensor, & catalytic convertors. Rebuilt engine has 20,000 miles on it, in a 92 525i with 95,000 miles.
Has anyone experienced a similar problem or have an idea what might be causing it?
Thanks in advance!
Super Moderator
Major Contributor
No rotor and cap on an M50Originally Posted by shogun
1988 M3 - Track rat
1989 325iC
1995 530iM
2000 323iT - UUC BBK, PSS9 Coilovers
2005 GMC HD Crew
Big Time Poster
check the injectors as well... mine had a slight blockage in one... also check HT leads, distributor and rotor arm...
Major Contributor
Could just be something simple like the air filter.
Super Moderator
If its not the cat plugged up again then i would check one or more of the
coils for poor output, someone else had that same problem with an m50 and it turned out to be a couple of bad coils....
3 Grand Master
That's what I was thinking....restricted flow at the cat. best, whit
Major Contributor
He replaced the cats. Coils should cause a miss at idle if they are going bad.
1988 M3 - Track rat
1989 325iC
1995 530iM
2000 323iT - UUC BBK, PSS9 Coilovers
2005 GMC HD Crew
Super Moderator
Baloney, even though he replaced the cats if there's a
problem such as unburnt fuel it will kill the new cats very quickly. And typically a weak or bad coil will have more than enough energy to light the mixture at idle when with the throttle bore is closed. But not so when accelerating under load.
Green Beret Special Ops
yep the old blow the spark out in high wind theory.
I would check them (coils) first because even if you replace the cats your gonna dump more raw fuel in there and kazam! just like magic youll be asking the same question a month from now.
OT: I used to be on a forum where guys would have super powerful ignition systems getting high speed miss...chasing things and spending thousands of dollars and of course I wouldnt get the credit for being nut on in the first place. You have high compression and a miss at 7000rpms...lets see here, whats the plugs gapped at .045...LOL Try .030...that would start all kinds of stuff going. I dont need to gap them that small I have 30 bazillion volts...whatever man.
95 E34 530I V2.37
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