Re: Stumbling at low RPMs

[alex.fadeev@xxxxxxxxxxx]

"Shaun Dustin" <sdustin@domain.elided> wrote:
> I've been lurking for a while, and now need some help. I have a '91 
> 318i E-30 with the M42 engine. In the last 50 miles or so, it's 
> started to have a hard time at the low end of the RPM range stumbling
> and missing, not much power. 

Shaun,
If you had an M20 engine, my money would have been on a sticking Idle 
Control Valve. If M42s have it, take a look.
Also, M42s are known for head gasket failures in the 70-100K range. How 
many miles on your car and have you had the gasket replaced? If not, take 
a close look at your coolant and oil for any signs of cross mixing. 

> I changed the fuel and air filters about 500 miles back, but other
> than an oil change, those are the only recent changes. It only seems to
> happen in the low end, between idle (750 RPMs) and 2500-3000 RPMs. I 
don't
> feel it above 3000. I guess the best way to describe it would be
> underpowered through that band with an occasional kick in the back as it
> randomly fires correctly, if that makes sense. Any ideas would be
> appreciated.

Any correlation between cold/warm/hot engine and the stumbling?
Part throttle vs. WOT?

alex f

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