Ended up taking back the EGR solenoid. If a new one was exhibiting the same "fault" that my Chilton/Haynes books were describing, I started suspecting that the book(s) was wrong since the book had already steered me in the wrong direction on testing the coil. And the Chilton manual would also help me in making a really stupid mistake (more later).

When I tested the coil per the book it was out of spec. AutoZone said it tested OK, but test obviously couldn't test under load. I decided to go ahead and replace my coil. This got the engine running OK when it was cold. As soon as it warmed up, all engine power was gone and it wouldn't hold an idle at all.

So started checking all the sensors I could find. As JohninLV mentioned, my Thermac valve was leaking. Just a little bit. Replaced that and went ahead and replaced about half of the vacuum connections (they looked brittle).

Engine once again started right away when cold. As it warmed up, engine started losing power. Was missing and backfiring quite a bit. Sounded like timing was way off. It was set at 8-9* and ECU was bumping it up to 18* or so. It sure sounded like timing though. Started thinking about firing order, and looked again at diagrams in Chilton (Haynes doesn't list). The Chilton maual shows the 2.8 to be a four clynder... Since I'd already found a couple of errors in the books I did a search here and sure enough - the firing order of the distributor is in the opposite direction of what books shows. Shuffled around the plug wires and the engine was purring!

Now I was making progress. Reset the IAC, readjusted the idle stop screw (warm idle at a very constant 805rpm), and rotated the TPS so I got an exact .5volts at no throttle. Engine is running far better than it ever has. Top-end is lacking, but I'd expect it with this engine and it's restrictive airflow.

I really need to get a Helm book for this thing. I don't trust the Haynes and Chilton ones anymore. I'm way too rusty at engine work (been almost thirty years since I removed a carburetor) to be chasing ghosts and troubleshooting my frickin' manuals. I'd hoped to find a definitive cause of our problem by methodically replacing/adjusting a single item at a time. But since most all the troubleshooting was done with the firing order all screwed up, makes it hard to know what actually fixed it. Major "D'oh" here... <img src="/forums/images/graemlins/cheers.gif" alt="" />