'94 G50: Massive Fuel Consumption Event

[sdkhalsa]

I was driving down the freeway a week ago when all of a sudden the engine died. There was a heavy odor of fuel near the exhaust, and I believe that there is fuel odor in the coolant. Earlier in the trip I had checked the fuel and there was more than five gallons left at less than 10 miles before the breakdown, but at the point of breakdown, all the fuel was gone. The car had been consistently running great, with very consistent mileage of about 17-20, no missing, and there was no leakage at the fuel lines. My thought was that one of the injector o-rings(injectors between 1-2 years old, o-rings 1 year) might have eaten it, and I was expecting to see a huge carbon build-up on a single spark plug. Today when I pulled the plugs, they were all very black, indicating a systemic problem. I am trying to think of what could cause such a huge blow out of fuel. My first suspect is a stuck fuel pressure valve; second suspect would be a defective temperature sensor. A failure in most of the engine control circuits like the MAF or IAC might result in poor mileage, but not blowing out five gallons in less than ten miles. There are no diagnostic codes. Unfortunately, the starter died when the engine backfired while trying to start car( some degree of hydro lock), so I am a bit limited in diagnostics at the moment.

A side item, when I opened the hood at the time of the above problem, there was a lot of coolant boiling out, leading me to wonder if this fuel problem had blown a head gasket -- which could account for fuel odor in coolant. I pressure checked the coolant system and it seems to hold pretty well, although there is a slight leakage, but that may be in the test equipment. With this inconclusive result, I think that I will have to restart the vehicle to make a further determination.

Any ideas?