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W164 GL450, W221 S550, R230 SL600TT, R170 SLK230, W140 S500, More
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Discussion Starter #1
I sold my awesome black 1987 300E a few months ago, then missed it so much I began looking for another 300E and stumbled upon a gold 1986 (color: Champagne Metallic with Java leather interior, close to Mint...) that was previously owned by a German guy named Arnold who was a MB mechanic for 40+ years. I have noticed the gold car isn't as fast or quick as the black one was, it's got a fresh tune-up, fresh oil, etc., but just doesn't seem to run quite like "Blackie" did. In comparison it runs like it's de-tuned somehow, probably for fewer emissions...I did a VIN lookup and the gold one is a california car. Could this be the cause? What was the difference in CA cars? Since it's no longer in CA what can I change to make it run like I think it should? Thanks for your input...
 

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300e 4Matic
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don;t knwo too much about mercedes as a whole but i'm pretty sure theres a "check engine" light on your dash. (CA only). This system may be doign something in order to meet californias much stricter emissions. It also may be the exaust. I'm not 100% but I this might help.
 

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W164 GL450, W221 S550, R230 SL600TT, R170 SLK230, W140 S500, More
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Discussion Starter #3
exhaust and maybe ignition timing, etc.

Thanks, there are no warning lights lit on the dash, it all seems to be working properly but it just lacks the oomph the other car had, I bet it is the exhaust being more restrictive, maybe the ignition timing is slightly retarded to further reduce pollution emissions. I will check into this some more and let you know what I learn..
 

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Don't know for sure on this particular model, but many california cars used an exhaust-gas recirculation-valve to help clean-up emissions.
 

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Discussion Starter #6
I will look for an EGR valve. -Where should I look on the engine for numbers? Thanks:cool:
 

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'90 260E, '92 300 SEL
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tonylinc said:
I sold my awesome black 1987 300E a few months ago, then missed it so much I began looking for another 300E and stumbled upon a gold 1986 (color: Champagne Metallic with Java leather interior, close to Mint...) that was previously owned by a German guy named Arnold who was a MB mechanic for 40+ years. I have noticed the gold car isn't as fast or quick as the black one was, it's got a fresh tune-up, fresh oil, etc., but just doesn't seem to run quite like "Blackie" did. In comparison it runs like it's de-tuned somehow, probably for fewer emissions...I did a VIN lookup and the gold one is a california car. Could this be the cause? What was the difference in CA cars? Since it's no longer in CA what can I change to make it run like I think it should? Thanks for your input...
It feels detuned because of the emission restrictions they put in the car. Plus a low compression engine.
Simple mod would be to remove the timing resistor, this resistor was installed to retard the timing, removing this would give you a timing of 0, therefore making you quicker off the light. But don't equate this to HP gains, this is just the timing. Resistor would be located near the brake hydrovac, wrapped in electric tape, mine was attached to the expansion valve line of the a/c.
 

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It's true that many cars exported to the US had detuned engines compared to their Euro cousins, though this was not limited to California, but applied to the US in general. This is not because of emissions, but because the normal fuel grades in the US are generally of a lower Octane than in Europe. I believe 91/92 RON is typical in the US, whereas Europe is mostly 95 RON or even 98. So, to account for this, some engines had lower compression ratios. Many MB engine ignition systems were also fitted with selectable resistor plugs, which alter the ignition timing to optimise for different fuel grades. Sometimes there are two plugs: one in the engine bay, which is user selectable, and another somewhere near the ECU, which is sealed with a tamper-evident tag.

For emissions, California introduced requirements for Catalytic converters and prior to that (and sometimes in conjunction with that,) EGR valves were used to partly "re-burn" some of the exhaust. Modern engines with variable camshaft valve-timing can now also acheive the same EGR valve effect, without an actual separate valve on the exhaust.
 
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