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B230 NA Rex-Regina, Approximately 160,000 miles.
For some time, I've been trying to nail down an over-rich running (fuel smell) problem. The car still runs fine. It just stinks to high heaven when sitting still idling. No fuel leaking anywhere. Around town mileage may be suffering very slightly, but I'm still getting about 26-27 MPG on the open road. I pulled the coil apart and cleaned everything. Spark plugs come out looking good. Yet it still smells like it's dumping fuel through at idle. I have NOT measured the rail pressure yet (no shraeder valve on the 740 rail), nor have I pulled the cold start injector to see if it's seeping fuel. A few weeks ago I read out the fault codes and even though I got stuff related to O2 sensor, the codes were random - after clearing them back to 1-1-1, I would get a variety. I cleaned the ground strap connections on the back of the engine where it grounds to a lug on the firewall. I replaced the catalytic converter, as the old one (Walker) was still under warranty and the parts house had no hesitation at all in replacing it. Nothing helped.
Jump ahead a couple weeks....
Wife calls and says "The check engine light is on." I go to read back the codes, and the display won't light up at all - not even a 1-1-1 on either socket #2 or #6. I took the display apart as much as I could and cleaned the internal contacts, etc. - still wouldn't light up. I don't know if the light is just burnt out or if there is no signal from the ECU. (I finally cleared the check engine light by disconnecting the battery for a few minutes.) I tried to play my VOM into the equation at the display unit to see if I could detect some needle swing in lieu of the flashing light. But not knowing the the exact wiring logic, or what voltage to expect, I came up empty handed. I know there are four wires feeding the display, and one is black which I will assume to be a common ground.
Soooo.....What thinks the BB? The ECU has never been disconnected that I know of, so I'm starting to wonder if the plug contacts are starting to build some corrosion or the ECU grounding is getting flaky. What else could cause the OBD display to go dead? Could the dead display and rich idling be related? Since it still runs good and returns good highway MPG, I don't really suspect the FPR. I could however suspect a dripping cold start injector as something that would affect the idle mixture more that the highway cruise mixture. I'm at a loss here, as I'm too cheap to start throwing parts at it until I stumble on the problem.
Sorry this got so long. Thanks for any ideas.
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