4ze1 running problems

[Gdrkbluemu]

G’day,we have just purchased an 1990 Isuzu mu 4WD ute with a 4ze1 2.6 litre fuel injected engine which, when started ,,runs beautifully.
The problem is that some times it is difficult to start.
The engine will fire immediately,but,when the key is let go off crank the engine dies.if the key is kept on crank the engine will continue to run.
When this is happening and the key is released and ignition is left on the vehicle can be clutch started and will continue to run as per normal.
The next time the vehicle is used it may start with no trouble or it may do the same thing,doesn’t matter if is hot or cold or what the ambient temp.is,or rain or shine.
We would appreciate any feedback or solutions to this problem as the vehicle is on a property 280ks away and we do not know what to expect each time we go out.ta.

[zzzmick]

Did you get it working? You might check the fuel pump and relay.