My '86 240 sedan, with almost 200,000 miles, is stalling out at stops. It doesn't happen at every stop, but I can't see a pattern. At first it seemed to stall only when at or below a quarter of a tank of gas. But now it's stalled when almost full. I've checked for vacuum leaks and have found none, unless I'm missing some spots. I thought it was a short in the wiring harnesses that run under the flywheel, but they both look fine. Wasn't sure if it was a fuel pump issue. Any ideas would be appreciated. Thanks.