Mercedes Benz - 04 2.1 Engine wont rev

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Sat 21 Feb 2009 17:28
04 2.1 Engine wont rev - petroldrinker
You may have read my earlier woes with this van. I've worked my way through the faults one by one and I have now got all the lights to go out but I've come up against a problem that I can't get any further with. The engine wont rev above 3000 rpm even in neutral The air filter looks new and I've put some injector treatment in the fuel and it hasn't made any difference. The van seems to produce plenty of power at low revs but looses it above 2500 rpm.
This equates to about 60-65 mph full-tonk. Not very good.

Any ideas where I should be looking next?

Thanks.
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Sat 21 Feb 2009 18:06
04 2.1 Engine wont rev - gordonbennet
This rings a bell, not as a fault maybe but is it possible that the first owner had the engine speed governed to prevent thrashing.

A previous employer did this to their vans (VW LT), it was cheaper than having a proper road speed limiter fitted, and stopped thrashing between the gears.

I daresay this is drive by wire, so no good looking for a removable fitting on the throttle cable or fuel pump governer screw, but maybe worth a butchers anyway.
Maybe it will need to be removed electronically if this is the problem.

Probably nothing of the sort.
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Sat 21 Feb 2009 19:00
04 2.1 Engine wont rev - petroldrinker
Interesting thought. I tend to feel that a fault is more likely but I will have a look.

Thanks.
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Sat 21 Feb 2009 19:28
04 2.1 Engine wont rev - Number_Cruncher
This sounds like the sort of thing an ailing mass air flow sensor might do. Sometimes a temporary improvement can be had by giving it a good clean with carb cleaner.

If you check this, and find the MAF to be at fault, don't be tempted to buy a cheap non-genuine copy - well know auction sites are a popular haunt for these. However, for some MBs, a Pierburg replacement insert is available which can be cheaper to but than a full MAF, and works quite well.
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Sat 21 Feb 2009 20:42
04 2.1 Engine wont rev - petroldrinker
Will definately try that and let you know how it went. Thanks for that.
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