W108 3.5 Misfiring Issue - Mercedes-Benz Forum

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post #1 of 3 (permalink) Old 11-04-2012, 10:52 AM Thread Starter
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Unhappy W108 3.5 Misfiring Issue

Hi Folks,

I have recently bought W108, 1972 3.5 V8 which was stored for few years. Have misfiring issue, rough running with black smoke with loads of unburnt fuel.

Following things have been carried out by Mechanic:

1- Compression Test (Equal Pressure in All cylinders)
2- New spark plugs, leads, rotor and distributor Cup
3- New fuel pump
4- 2 New injectors as fuel was leaking out.
5- Spark in all leads

Having taken out spark plugs after misfiring, unburnt fuel and plugs were wet with fuel.

Advice and opinion is needed and would be greatly appreciated for any ideas what could be issue as my mechanic has no idea what else could be wrong.

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post #2 of 3 (permalink) Old 11-04-2012, 06:43 PM
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I would have all of the injectors rebuilt. I had mine done by Injector Rx here in Houston. They are a very nice South African couple.
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post #3 of 3 (permalink) Old 11-05-2012, 04:08 PM
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Vehicle: 73 280SE 4.5, 71 300SEL, 03 BMW Z4, 72 Fiat 850, 80 Triumph TR7, 85 Porsche 911
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Check the trigger points too.

I'm assuming you dumped the old gas and started totally fresh with new stuff?

What about points/condensor? Have you replaced or adjusted? I'd recommend dumping the wole setup and going with a Pertronix setup. MUCH better running.
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