I bought a Lexus 1998 Repair Manual for the GS400 GS300 for about $140 to see if the fuel systems are even similar. There are several differences but after talking with several mechanics (Lexus, Toyota, and Heavy Construction {my career}), they all tend to think that the higher fuel use suggests a fuel leak somewhere. I sent a motor oil analysis off Friday so it may be a week or two considering the holidays before I hear back.The scary thing is that if I had almost 3 quarts of extra gasoline in the engine crankcase mixed with the motor oil, it could have diluted the oil to spin a main bearing, cause a seizure, or worst yet, exploded. We've been most fortunate thus far!It appears that the injectors screw directly from the fuel rail to the head. If so, then it may be a(n) injector(s) with trash in them not letting the fuel turn completely off when the engine switches off.When I posted this thread, I was under the assumption that there may be a short piece of fuel line from the fuel rail going into the head before attaching to the injector. After a closer inspection, I think this initial assumption is incorrect.Does anyone have any ideas on this problem? Thanks...
