I've got a 1991 Toyota Xtracab 4x4 with a 3.0 V-6 and 460,000 miles (it i s nearly broke in) that has been my daily driver for the past 25 years. Last Friday I pulled the plenum to replace the small 8mm (5/16") u-shaped co olant hose that runs from the temperature sensor housing to the metal retur n line near the firewall. I reinstalled all vacuum hoses and electrical co nnectors and have gone over them twice to verify they are correct. Since I did that service twice now I've driven the truck 25-30 miles with several stops along the way and then all of a sudden it will crank over bu t not fire up. Each time this occurs there is a strong fuel smell from the exhaust pipe. I'm guessing I either have an intermittent spark issue or po ssibly the choke is closing and flooding the engine. After it sits for 30 minutes or so it will crank over and start very slowly like it has too much gas and after 15 seconds of sputtering wake up and run fine. At that poin t I can turn it off and back on several times and it starts up just fine ag ain. I've verified all of the vacuum hoses are connected to the correct ports and the few electrical connections I removed have been reinstalled. I'm th inking about looking for brittle wire insulation to see if something flaked off on that 25 year old wiring harness and is allowing two bare wires to t ouch when things get hot. I checked timing, plug and coil wires, and fuel pressure as well. Any ideas would be greatly appreciated.