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Discussion Starter #1
Have a '96 C220 Elegance, anyone have a view on whether it is harmful to the engine to tap the accelerator lighty when starting the car? This is only because lately occasionally I find the benz a little wobbly on the start and giving it a little tap helps smooth the starting. Given the age, and with no particular pattern to the problem, remembering that with this model year the aircon is set to always come ON when the car is started (regardless of previous setting before switching the car off). Thus I feel the engine being taxed a little more than usual hence sometimes the revs drops very quickly after starting and one can hear the engine gulp! Any advise what could be causing this or should I just let it rest and continue with the light accel tapping? Thanks heaps guys.
 

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2004 Lexus LS 430 Modern Luxury. 2012 Acura TSX (fun fun) Maybe MB again one day...
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You should not have to tap it on startup.

What work have you done to it? Tuneups? Service?
 

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Discussion Starter #3
Last major service was completed last Nov at recommended Benz/BMW specialist. Clocked 93,000 miles. Off the top of my head the following was done to the car:

- new petrol filter put in (improved performance immed!). Old one was very clogged.
- new engine mounts fitted
- radiator neck slight leak patched
- usual spark plug and engine oil chg
- auto transmission unit cleaned/patched and oil chged
- benz specific reconditioned aircon compressor fitted. Old unit was leaking badly and rust around the aircon clutch.

I know with our cars one shouldn't need to tap accel being injection and all - what is the damage caused if I do?
 

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Tapping should not be required when starting the car cold. However, it may be required when starting the car hot.
This is described in the owner's manual by the way.
 

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2004 Lexus LS 430 Modern Luxury. 2012 Acura TSX (fun fun) Maybe MB again one day...
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That is in the owners manual????
 

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Requiring a throttle tap to iron it out when it's cold is usually an indication that you are leaking compression out of your piston rings, but when the car heats up, they expand and seal.

You can check this by doing a cold compression test (be sure the car has not been driven in at least 6 hours... longer is better) and seeing if everything is in spec. I don't own the repair manual for that year, so I can't tell you what the exact spec is, but more importantly I would look for any cylinder that deviates greatly (more than 12 psi) from the other cylinders.

If that's not it, it might be something dumb like they didn't tighten the spark plugs all the way.

-Ray
 
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