I've got a 740turbo and it has a slightly rough idle.

The idle doesn't change rpm much, but I have a vibration that goes weak,weak,weak,strong over and over.

I suspect it might be the injectors for no really good reason except that the spark plugs are in the middle of their life and ut feels like one cylinder fires okay sometimes and like crap other times.

Also, my mileage isn't what I hope it could be. I got 22mpg for a couple weeks before the gas mixture changed (in october), but usually average 18-20.

So, I'd like to know what benefits have been found from off-the car, send-away fuel injector cleaning.

I assume there have been problems with logistics, etc, but I want to know if anyone saw a noticeable efficiency or engine smoothness change. I do run Chevron almost exclusively, but it's not like that's wonderful.

-Will
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1990 740 Turbo, on its way to stock specs, maybe beyond