[1970_240z]

have a junker 280ZXT that i want to pull the motor from. i got the engine to crank, it has a fat spark, but the plugs stay dry no matter how long i crank it. i got some starter fluid and it fired right up like it was just running yesterday, but not even a hint of gasoline getting to the cylinders. the injectors have current going to them and the fuel pump works at least well enough to pump the old gas out (which i already did). this car has been sitting for a while, but the only problem now is getting the injectors to deliver the goods. any ideas?

 

[79-280-ZX]

Put a fuel pressure gauge between the fuel filter and the fuel rail. You should have 42 PSI while cranking the engine over. NO, change the fuel filter.

Remove the Cold Start Injector and put a piece of hose on the fuel line and put the other end in a clean container then crank the engine. Does fuel come out?

Disconnect the return fuel line at the fuel rail and run a hose into a container. Crank the engine. Does fuel come out?

While cranking the engine can you hear the injectors clicking.

If you get fuel and pressure at this point, hook the cold start injector back up and build a jumper to apply 12 v to the CSI. Does the engine start?

Wayne Monteath
Masham, Quebec.

 

[TurboSi]

I, too, suggest that you start by checking the pressure after the filter but before the fuel rail to insure that there is fuel under pressure available to the injectors. The Turbo models, however, have no cold start valve - the ECU is used to increase the duration of the injection when the engine is cold. In fact, the ECU in the driver's side kick panel controls everything about the injection of fuel based on information it receives from about a dozen places. If you have adequate pressure, I would check the connections at the ECU. Wayne is correct to listen for the operation of the injectors while cranking or while on starting fluid (long screwdriver touching injector with the handle at your ear). Check back with us if you determine that the injectors are working.....get's really serious then!

 

[1970_240z]

thanks guys. i have not checked the actual fuel pressure, but do know that there is fuel coming through since i drained the old gas out from an open line after the fuel filter. i'm assuming that even if there is low fuel pressure i will get something out of the injectors? the plugs are bone dry with no hint of gas. i checked the ecu and the connections are all very clean there. is there a ground or something that might not be making a good connection? is there any chance that all 6 injectors are completely plugged up? thanks, marcus

 

[79-280-ZX]

Please explain " but do know that there is fuel coming through since i drained the old gas out from an open line after the fuel filter".

Exactly, how did you drain the fuel tank after the fuel filter?

Did you change the fuel filter after you did that?

How many cc of fuel (or ounces) per second did you pump out AND at what pressure?

Can you hear the injectors clicking?

And, yes, it is possible that all 6 injectors are plugged up, BUT, not likely. The most logical answer is that the fuel line is restricted or the fuel pressure is not adequate.

Wayne Monteath

 

[1970_240z]

<<Please explain " but do know that there is fuel coming through since i drained the old gas out from an open line after the fuel filter".>>

the fuel ine was cut right after the filter when i got the car so i fugured it would be a good way to drain the old gas out. i just turned the ignition on and off until the fuel was all pumped out of the tank.

<<Did you change the fuel filter after you did that?>>

i have not changed the filter yet, but will do so. i know that it is not blocked since fuel seemed to flow freely when i drained the old gas.

<<How many cc of fuel (or ounces) per second did you pump out AND at what pressure?>>

i have not bought a fuel pressure guage yet, so i do not know, but shouldn't it be getting something into the cylinders if there is fuel in the rail? i also did not hear an audible clicking when i used starter fluid to start it or when i crank it. that's why i suspect something else is amiss.

marcus

 

[fallon]

if the regulator is frozen open the car wont run. Pinch the return line with a pair of vice grips and try and statrt it again

 

[79-280-ZX]

Ok, so you do not care if you have enough fuel pressure to get the engine to start.

Take the bulb out of a three volt flashlight and hook two wires to it. Remove one of the connectors to a fuel injector and put the end of the wires into the connector.

Crank the engine. Does the light bulb blink?

Yes, check the fuel pressure.

No, check the ECU. To know which pins on the ECU harness to check you are going to have to tell us what year the engine is.

Wayne Monteath