Well, about two months ago, I went out to start the Blazer and nothing. Starter turned, just no spark. Towed it in to my mechanic friends. They found that the ECM was tied into the interior fuse panel with a bunch of random things. The auxiliary cruise control lever was shorting on the steering column and knocking out the ECM. Powerfully stupid. I asked them to strip all the 40 years of random wiring out and do it like a smart person. They did a great job. But here's something funny. While working the RamJet harness, they found a plug not going anywhere. After a little research, they realized that the original installer just failed to plumb in the IAT sensor. The ECM, without the sensor, reads -40F for intake temperature. So.....I was running a tad rich. Here is the solution:
