1988 Ford E-Series Van Engine stalls when hot

Tioga motor home. Until this summer run perfectly. Coming from San Diego the driver side exhaust manifold leaked hot exhaust gas that burned the upholstery on the inside engine cover. Ford fixed the leak (No. 10 worm gear hose clamp, snap-straps, furnace cement) 10 days ego. Drivibg the car from the Sacramento Future Ford Fleat Center, the idle was immediately rough, and the car stalled after about 10 miles. Towed back to the service, Ford run a computer check (four numbers, will have them tomorrow) and decided to replace the EGR valve, and fix a vacuum hose. Drove from Ford Center on Thursday afternoon to storage (cca. 20 miles) it already run rough but got there. Saturday drove about 8 miles: at the end, when switched to park, the engine stalled and could not be started. Today (relatively cold engine), started, but the idle was very rough. Drove about 20 feet and stopped. Appears the mixture is rich (smells gasoline). Certainly temperature related but have no idea what it can be. I was to sell it (~$7,000 - everything is in good working condition) but I can't this way. I will get the codes tomorrow. Would greatly appreciate any advice - other than get my money back from Ford :-). Regards, Laszlo Gutai.