Questions and Answers

Toyota T100 Hard To Start And Smells Q. Greetings, Vincent! I have a 1994 Toyota T100 automatic transmission with 100,300 miles, P/S and A/C. The fuel injected 3VZE 6-cylinder engine has suddenly been very hard to start no matter if it is hot or cold. This began happening about a week ago. I have to crank the starter three or four times before the engine begins firing.

The starter and battery are brand new and cheerfully crank the engine. Then, the sputtering engine's RPMs gradually increase to the engine's normal warm-up speed (about 1,100 RPM's).

The smell of unburned gasoline lingers in the air after startup. I bought my fuel from other than my normal gas station, so I'm suspicious of the gas. Also, after the engine reaches operating temperature, there's a slight smell of rotten eggs in the air - my passengers give me side-long glances. The engine runs fine after it starts; no hesitation, plenty of power, no missing, that makes me wonder, "Gee, could it be the gas?"

In an effort to fix this fuel/ignition demon, I've replaced the spark plugs, wires, distributor cap, rotor and air filter. I didn't time the engine yet. I shot carburetor cleaner into the air intake side of the plenum to clean it. The butterfly valve moves freely, hoses look good, no leaking fluids.

Sadly, the hard-starting and smelly problems persist. My next ploy is to burn off the rest of the suspicious fuel this weekend (after I get the truck started) and refill the tank at my regular gas station. If that doesn't work, it's off to the Toyota dealership on Monday for an expensive experience.

Any ideas before I spend my kid's college tuition on a new fuel injection system? Thank you for your help, and I enjoy your web page, very informative!

Arnie

A. A fuel pressure test would tell the story here. I suspect a bad Coolant Temperature Sensor (CTS) is causing the mixture to go excessively rich, causing the rotten egg smell. The hard starting could also be a bad fuel pump check valve. The fuel pump check valve is supposed to maintain fuel pressure when the engine is off to make starting easier.

One way to confirm this is to cycle the key OFF - ON three or four times for five seconds before actually starting the engine. If, after doing this, the engine starts right up, then it is very likely a bad fuel pump check valve or fuel pressure regulator.