[myzdied]

My 81 zx non turbo will not start without copious amounts of starting fluid. Can ony get it to rev up with more starting fluid. I have replaced the fuel filter and fuel pump. I am getting fire and injectors have continuty. Today I took out the fuel pump relay and plugged a squeez bottle of gas into the fuel line. While trying to crank it I applied a lot of pressure to the bottle of gas. I figured too much pressure wouldn't hurt on start up. This made no difference so I pulled the plugs(brand new) and found they had no gas on them. Since the engine never fired over I figure they should have reaked of gas. I checked and the plugs are firing. So I'm thinking either the fuel rail is clogged (seems unlikely that all 6 injectors suddenly went bad) or the computer is bad. If anybody has other ideas I would appreciate the help.Thanks in advance.

 

[Tom D.]

Check out the injectors with a stethescope while cranking. You should be able to hear each one clicking. If they are clicking, they are being commanded to open and I would not spend too much time worrying about the ECU.

Tom D.

 

[79-280-ZX]

Put a fuel pressure gauge between the fuel filter and the top fuel rail. Disconnect the small gauge wire at the solenoid and turn the key to "start" and hold it there for 5 seconds. With the wire disconnected the engine will not turn over and the fuel pump will run. The pressure should go to 42 PSI. Put the wire back onto the solenoid.

Build a "NOID Test Light". Get a 12 volt 3 watt light bulb and hook two wires to it. Remove a connector from a fuel injector and stick the loose ends of the wires into the connector. Crank the engine over and the light should blink. Note that there are two power transistors in the ECU that fire the injectors. Cylinders 1,2 and 3 are controlled by one of them and cylinders 4, 5 and 6 by the other.

Check your battery voltage. With the key "off" the voltage should be at least 12 volts and while cranking if the voltage drops below 9 volts the ECU will not fire.

Try these three simple tests and report back with your results.

Wayne Monteath
Masham, Quebec.

 

[fallon]

the pressure regulator can stick in the open position giving zero pressure as all the gas returns to the tank. If the fuel pump runs pinch the return line and see if she starts. Do not run the girl this way for long as the fuel pressure will cause the pump to whine and burn out. Also the car will flood.