ok daughters boyfriends 78 280zx has been sitting for about a year before that ran fine now the oil is diluted with fuel we changed the oil. Started catr ran for 30 seconds then nothing tried and tried and let sit the night next morning start ran for 30 seconds again then nothing. oil is diluted with fuel again. dont know anything really about these motors hoping someone has had this problem and could help us out or buy the car as it sits we are located in Aumsville Oregon. The kid is 18 and does not have extra money to dump into trying to figure it out a a repair shop would rather move on to something else that easier to work on and will cost less in insurance. any help is greatly appreciated. 

see if the cold start valve is stuck open.

check the FPR see if its leaking fuel into the vacuum line that connects to the intake manifold.

Edited August 4, 20177 yr by Dave WM

had a mechanic friend said to check the FPR cranked it with the vaccum line off no fuel or anything even tried changing the stemp sensor under the thermostat the two wire one still wont run. took the TPS? off maybe well a different diesel Mechanic friend did the black box with wires down by the core support. anyways with the intake tube open with key in start position and throttle wide open you could here fuel spraying seems to be not right to us but it was 106 out yesterday and didnt spend much more time outside messing with it.

 

pull the cold start valve out of the manifold (two screws) see if its leaking, should not have any spray or leaks this time. Be very careful about how you plug in the CSV and the Temp sensor, don't mix those up, they look the same (bullet connectors on the wire harness and the injector plugs ).

Edited August 4, 20177 yr by Dave WM

If the CSV is stuck open, you could just disconnect the fuel line and plug the fuel line going to it for now.

Edited August 4, 20177 yr by Dave WM

i removed it and its suity looking but dry. turned key on with it out but unplugged no sound. then i tried it with it out but plugged in and no sound tried cranking it over and it had a hard time turning over removed four spark plugs cranked it and raw fuel shot about 5 ft out of one cylinder number four maybe from the front to the back. I appreciate your help been trying to sel or trade it the way it is not much luck with that either though

 

 

oh ok so you have a stuck fuel injector.

so after more investigating and talking with the kid the injectors were replaced not long before he bought the car. the injectors were unplugged from last night so i had him turn the key to the run position and i opened the throttle wide and could hear each injector spraying as i plugged and unplugged them. Am I right in assuming that unless the car is running or cranking over there should be no fuel spraying from the injectors? So in that case then something else going on with the ECU or something injector were replaced on 8-21-2015

 

right that is the way it supposed to work, a signal from the coil tells it to fire. Maybe the ECU is fried. You should read up on the FSM about voltage checks at the injectors. I wonder why the injectors were replaced? an ill conceived fix for the current problem?

Edited August 4, 20177 yr by Dave WM

Without holding the throttle wide open try and crank it over.  I've heard of the injectors magnets getting stuck after sitting for awhile.  Try tapping each one with a screwdriver handle.  The injector replacing in '15 might have been an attempt to fix the real problem?

This is for a '77 but should be the same.  The EFI may not be grounding and running continuously.  Clean the grounds.

http://atlanticz.ca/zclub/techtips/electricalconnections/index.html

Make sure these aren't crossed.

Edited August 4, 20177 yr by siteunseen

So i was reading somewhere and the ECU is on the driverside kick panel inside the car? if so maybe he fried the ECU i have to ask him when he gets back from the store but before the car sat he wrecked it and went into a ditch and the ditch had water in it not sure if the water got inside the car and could have gotten to the ECU or whatever