92 300E: Getting it Started & MPG
 

When I'm starting up in the morning, it doesn't start right up; I have to give it a little bit of gas. I just got one of the full fuel system cleaners, and I poured it into my tank when I filled up yesterday. Seems to have helped a bit so far, I drive alot so I already used a quart of my tank. Is there anything else I should take a look at?

Ok, other than that, the car has 173k mi on it, and is still running smoothly. I've gotten pretty great gas mileage, with my lowest being 19.82mpg and my best being 26.4mpg, and averages 22.46mpg (I'm keeping all of the info on my handheld, with a mileage calculator I have). I'm pretty sure that's very close (if not being) the sticker mileage when originally sold. The car is bone-stock, nothing has been done to it other than regular maintenance (I even have the service manual. and yes, the service tags have been pulled out according to their proper dates and mileage, with accompanying paperwork. I have so much info its like I bought this car for the original $44,819 it was sold for (also have that paperwork ;).)). Is there anything from the aftermarket world I should consider to improve gas mileage or performance?

Thanks guys :)

Very common M103 problem..

Here are things I would check: (from cheap to expensive)

- fuel pump check valve (~$15 at partsshop)
- fuel accumulator (next to fuel pump, ~$120)
- fuel pressure regulator (under air cleaner next to fuel distributor, >$200)

Theres occasionally a slight shudder when in drive, but stopped for bit, idling. Would this be consistent with one of those part specifically?

I really can't say.

If you feel a vibration, or slight shudder, when idling, it would suggest worn out motor mounts.

My best guess on the poor starting issue would be fuel pump check valve, anyway.

That's whats odd, I doubt its the motor mounts because its only an occasional shudder...

Anyway, my mechanic has a check valve he told me to swing by his house tomorrow night and we can take a look at it. Thanks for the help.

Your MPG is on the low side.
I'm just returning from a 1610mi. trip. With the A/C on all the way, traveling through lots of mountain road, I achieved 31.8MPG.
The car has 256K on the clock.
JackD

Wow... ok, I'm definitely in need of a full checkup... I guess it will keep me busy tonight.

31.8MPG! Wow .....

That has to be a typo or a math error.

There's no way a 260E (or 300E 2.6) or 300E or E320 could get that kind of fuel economy.

21.8 I could accept....

Imperial Gallon ????????

Most Likely
 

Imperial.....It raises a lot of eyebrows when I tell people that my 600sel gets 26.5 to 27mpg at 120 kmh (70mph) but you have to remember that is in imperial gals (20% larger gallon, I think). Hell, my 97 Taurus SHO only got that at the same cruise speed.