I'm relatively new here, I tried searching for some answers, found close enough ones but no pinpoints . Anyways I'm a proud owner of a 1991 W124 2.6. Even though my car has problems I love it do death and try to find ANY way around having to get rid of it. Last major repair I did was a tranny replacement for $700, so it wasn't that bad .


Anyways, lately, I've been getting HORRID gas mileage on my car, 14 MPG to be exact. I recently (within a month) replaced my spark plugs (which took forever to find the RIGHT OEM ones, Bosch non resistor, copper core plugs), replaced the fuel filter, I've got a year old K&N filter, and my tires are inflated to proper PSI's. My question is, I've tried and I give up, anybody here know what could be the problem?

Another problem I've got is that my Idle Air Speed Control or whatever it's called, malfunctions. It stays relatively closed, thus my mechanic adjusted my fuel/air mixture so my car idles at about 1,200 RPMS, when you put it in gear or turn on the A/C it drops to about 700 then when you turn on the other/put it in gear, it goes down even more to 500. My point is the Idle RPM's aren't regulated to stay within one place. Any ideas to what that could be? I was thinking the ECU but I'm no expert to blame that right away. Any helps thanks!

I'm a die-hard MB fanboy and get trashed at work defending the MB brand, lol. So I'd really LOVE to be able to keep my W124 and just get it up to a nice smooth condition, .

Thanks for any help guys!

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