Wonderful community you have here, you all have already helped me tremendously. I've got a little problem here I was hoping for some help with.
My 1988 300E recently failed its smog test in a big way. Way over the emissions limit. The tech mentioned the ignition timing was set at 24 deg BTDC, while his book said it should be 9 degrees. Any idea what causes this?
In the interests of full disclosure, I will also mention that that I replaced the O2 sensor a few months ago, the car has days where it will not idle at all, so I'm going to check the OVP relay and fuel pump relay this weekend. I have the eha test harness on order. I admit to having turned the 3mm allen screw under the air cleaner, having very little idea of what I was actually doing. A friend told me to hook a DVM on duty cycle to pin 3 and adjust to 50%, turning the screw seemed to have very little effect, the closest I got was about 43% average, the numbers were all over the board, no consistent range.
I am committed to fixing this myself even if it costs me lots of $ in tools, I'm slowly picking up the make and model specific knowledge in this great forum. I insist on learning all this because I'm about to sell my Jeep Grand Cherokee so I can buy my wife a early '90s 300TE, which I will also have to maintain. (I am very experienced in building/repairing late '60s american hot rods.)
Thanks in advance,