1988 300E running rich. Car starts right up hot or cold. Runs fine cold until warm then runs rich and blows black smoke. No erratic Idle(700rpm) or stalling. Changed plugs(black as expected), changed aircleaner, replaced temp sensor. Still no change. Otherwise the car performs well. Economy guage(vaccum) is in the middle at idle when warm(seems odd). I removed ovp(not mounted). Fuse looked good. Held cap, shook and no rattle. Black relay next to ovp looks suspect. Black electrical tape over connection. My fuel pump relay? Checked vaccum lines and nothing obvious. I've searched over 80 pages of threads and found no problem like this. I don't believe it's the o2 sensor. Symptoms seem to drastic for that. Any info from you old pros is appreciated. It's my first 124 and I'm not familiar with their inherent problems as with the 126. Thanks in advance for your time and replies.
Last edited by likemybenz : 07-12-2006 at 09:03 PM.
Replace the OVP, the Fuel filter, the fuel relay and your O2 sensor. If you have been blowing soot like this for a while, it means your 02 could be part of it, but it is now plugged for sure adding to the problem, also check your vac lines to make sure they have not cracked with age and heat, do a vac test on the system.
__________________
::Familie von Mercedes::
'00 German Sheperd ("Hans")
'89 300 TE 117k
'92 400E (killed in action)
'68 280 SE/8 (High School Sweetheart)
'95 E320 (mother's)
'60 190D (dad's new project)
'05 A6 Allroad 2.7t (dad's ride)
'84 190E (sold)
'90 300CE (brother's)
The thing that you need to address FIRST is the vacuum problem. If the economy indicator is reading midscale at idle you have a large vacuum leak. LARGE. Pull the air cleaner and note the location at every vacuum hose. There aren't that many. If necessary disconnect the hose from each one and plug it while checking the economy meter. That thing should be pegged at idle.
Linear Mode
