Weird, I just (finally) sent you a return email this very evening.

(For everyone else, I owe Mr. Sargent an apology for a VERY belated response to a question sent privately. I've been SWAMPED.)

That aside, however, I would definitely suspect the old gasoline. I'm not sure if it would be strictly confined to the reformulated variety of gas, or if it applies to all vehicles with certain types of plastic gas tanks (760T) or what the deal is. Perhaps some of both.

What I found to cause valve seizure, was a buildup of gum (varnish) on the valve stems. It was SO bad that the car literally stopped running on it's own. This happened to me with a Volvo 740T (twice with the same car), and once with an Isuzu Rodeo. The Volvo had it worst; the Rodeo re-started at a later date, and is fine.

When I took the head off the 740T the first time, I marked it for dead. The valves were practically painted with a brownish sludge, and were stuck in place.

Subsequently, the head was boiled, surfaced, the valves were cleaned up, new guides installed, and the head returned. One week later the boss called and had me bring the hook out to the alignment shop where he was stranded with the same car.

When we got the car back to the shop, we discovered the same thing, except to a lesser degree (since I had taken it for a little highway ride in between). That time, we were able to free the valves by tapping them down with a plastic mallet (camshaft removed) and using carb spray and PB Blaster on and off. He'd tap the valves down, I'd spray with carb cleaner. He'd tap the valves down farther, I'd shoot with Blaster. After about ten times, the worst offenders loosened up marvelously. Thereafter I yanked the tank and emptied it dry, and it was full of brown gasoline--the same stuff I found on the valves. It's amazing it didn't ruin the whole fuel system.

Apparently they had another similar case where they put three engines in one 700 series because they kept locking up. The reason they locked up over and over? Because they were sitting for so long, the gas was ruined.

Once I had the valves cleaned up, fresh gas in the tank, and a new timing belt (again) I took it out for a spin and it could cook the tires off. It was a good fix, and it was done right. But the cause still worries me to this day. It might be worth a trip inside the intake manifold to see if you can see anything on the intake valve stems. A good shot of Sea Foam fuel system cleaner might help it along, quite honestly. It is a good product. I am suspicious of why ONE valve would stick. Again, it might be worth a look inside the intake manifold. The exhaust is too much of a pain in the backside to take off just to look at the valves.

If you haven't gotten new gas into it, it might be worth it to empty the tank and take the thing for a few hour ride with fresh gas and some fuel system cleaner.

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chris herbst, near chicago