My '86 300E has 160k miles on it. After sitting unused for a couple of years, I started driving it again about one year ago and have had serious, ongoing driveability problems. I have replaced - or have had replaced - the following parts, but still have a minor idle problem and more recently difficulty restarting after it's warmed up (and a strong gas smell when it does start):

- Fuel pump (new Bosch), fuel filter, and pressure regulator
- Injectors incl. plastic sleeves, fuel distributor, and rotary idle actuator
- EHA valve, overload relay

All the obvious things like plugs, wires, rotor, cap, etc. are new or close to it. All vacuum leaks have been fixed.

Cylinder head was completely rebuilt at 145k; compression is +/-175psi in all cylinders; oil consumption is minimal; mileage is consistently 22mpg. Aside from the problems mentioned above, it runs great (after replacing all those parts).

I'm far from a skilled mechanic, particularly at diagnosis, but I have figured out how to replace lots of parts.

The dealer I took the car to, MB of Princeton, was beyond useless.

Any suggestions on what I should try next?

Thanks,

Gary

http://www.peachparts.com/shopforum/search.php?action=showresults&searchid=515474&sortby=lastpost&sortorder=descending

Based on advice I found here, the Bosch Platinums were tossed and replaced with Autolite coppers. Idle is now nice and smooth.

Thanks!

Gary

I have nothing against Autolite(they probably work great in Fords), but a Bosch copper H9DCO plug is what's best for your 103 motor.

My concern would be the heat range of the Autolite. Is it exactly the same as the Bosch H9DCO?

I tried to find Bosch coppers at a number of shops in my area, but came up with nothing. They all carry the platinums only.

What heat range should I be looking for?

Thanks,

Gary

You merely need to look for Bosch part # H9DCO. That plug offers the correct heat range. If you find part # H9DC, that too is acceptable.

The plug with the O on the end has a slightly wider electrode. I've used both and could not say one performed better than the other, although I prefer the beefier look of the H9DCO electrode.