94 E320 Engine Trouble, Codes 6 and 12
 

My E320 is acting up again. I am curreltly having trouble with warm starts (cold starts are fine!) and a slight rough idle. Yesterday i found the fuel line after the filter was gushing fuel. In hope of a major inprovement, i replaced the line today.. No fuel leak but still the regular starting problems that seem to get worse. I have checked the codes since the check engine light has been coming up the last few weeks. Clearing the codes after i replaced the fuel line did not clear them all. i am currently getting a code 6 and a code 12. What could be causing this??? i would love to be able to fix this problem, hopefully by this weekend. Your comments will be greatly appreciated!
Thanks,
Adam

On the 1995 E320 6 is "Idle speed control inoperative" and 12 is "Heated O2 sensor heater, open/short circuit". Replacing the O2 sensor is pretty straight forward.

Before replacing 02 sens., check fuse 6 and 7 in fuse box.

Also check under passenger front rug. You are looking for 12v at pins 1 & 2 at o2 sens connector w/key on. [ see above]
If you have that , check ohms across two white leads at o2 sens lead connector.

Okay, I checked the O2 sensor heating element, 4.5 ohms of resistance. It is getting the necessary 12 volts. and the O2 sensor feedback produces .440 volts. I guess that the O2 sensor is in perfect working order. I cleaned the throttle body today and now i have a high idle, about 1300 RPM. What should i try next?
Thanks!
Adam

I am assuming you mean you are getting an average of .440 v.
[ o2 is cycling ?]

With warm eng. and o2 sens. unplugged, take a sens reading when you unplug and cap the vac line to the fuel regulator.
[ sens should go rich 1v.]
Then, uncap the vac line [leave open to outside air], sens will go lean .1v.]

Also check ohms on sens heater to ground [although the heater
is in spec.] May have tripped #6 with an open circuit when hot.

ASR ???

Arthur
That is correct, cycling in average of .440 volts.

With the regulator vac line unpluged and capped i am getting .800 volts

With the vac line uncapped i am getting 30 millivolts.

I am also noticing gasoline dripping from the fuel pressure regulators vacuum connection, not much though, a few drops per min.

Thanks for your help!
Adam

Change the regulator.