Here's the scenario - wife's 93 240 had been getting worse and worse at idling, no matter what the temp was. So I finally got some time, took out the throttle body and cleaned it up with TB solvent spray, blew air through vacuum line ports in the throttle body, adjusted throttle position switch to get click when butterfly closes, etc. Car started and idled just fine for a few weeks, then began having issues again. I took off all vacuum lines, cleaned throttle body again, removed intake manifold and cleaned, replaced oil separator on block, replaced injector seals, replaced flame trap, took out idle air control valve and checked for proper function, reassembled everything. Car is extremely difficult to start when cold and requires non-stop pumping of accelerator and 2500-3500 rpms to keep running. After perhaps one minute of that treatment, the problem disappears completely and the car runs great. WTF is going on? This car does not have a cold start valve under the manifold, only the idle air control. Any ideas? Oh, forgot to mention, swapped out AMM with bone yard spare and with another AMM from our other 93 240. With any of those three AMMs, the car behaves the same. Runs GREAT after a minute of nursing from cold.
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