What?s causing my engine to misfire? - Bend Bulletin
-- returnText2 = Q: My 2004 Buick Park Avenue Ultra with 60,000 miles misfires when restarted hot. A: If the engine misfire occurs only during a hot restart, checking fuel pressure is the place to start. If the ready fuel supply in the fuel rail on top of the engine is overheated immediately after shutdown, it may percolate or boil the fuel. That would aerate the fuel with bubbles, causing a loss of fuel pressure at restart. As fresher, cooler fuel reaches the rail and injectors, fuel pressure comes back up and the engine smooths out. Another possibility for a loss of fuel pressure on a hot restart is a leaky fuel injector or fuel pressure regulator diaphragm. These issues would also bleed down fuel pressure right after shutting off the engine, causing a restart misfire. GM has recently recommended adding a fuel treatment to the fuel tank at every oil change to prevent this. Q: My wife has a 2006 Chevy Tahoe with 109,000 miles on it. Recently, after the car was driven on the freeway for an hour or so and then put through a stretch of stop-and-go traffic, the oil pressure dropped to zero and the low oil pressure... After the car was parked for an hour or so, she went out to start it. The oil pressure gauge went to 40 pounds per square inch for a few seconds and then dropped to zero. Source: www.bendbulletin.com
