need help car starts but will turn off after a few secs

[jesus]

hello all new here have been having problems ever sense i got the car my first problem was the distributor problems so i swapped that out for a 79 280zx one then swapped out the coil then the car ran more better the problem was that when it got up to temp it will go to a like limp mode it still did that after the new parts so after that i had an idea it was my transistor so i swapped that out for a gm control module then after that it only runs for a few seconds then shuts off and when i get it to run if i touch the gas it shuts off right away my car is a 1975 280z federal i get spark and fuel i dont know what it can be thanks for the help in advanced 

[wheee!]

Add a period here and there... helps with the reading.

Did you put a low resistance coil in? Did you remove the ballast resistor?

[JSM]

You said you have fuel, but how is the pressure? How long was the car sitting before you started working on it? 

[siteunseen]

Sounds like the fuel filter is running dry to me.  Runs until it's emptied.  Try clear filter after the filter but before the fuel rail.

My crudded up fuel tank did the same.  After it sat and the debris fell to the bottom it would run about one block then die out.  Took the hose off the filter outlet and blew into it until I heard bubbling in the tank.  Hooked it back up and drove it home, many times.  Then I figured it out.

[jesus]

4 hours ago, wheee! said:

Add a period here and there... helps with the reading.

Did you put a low resistance coil in? Did you remove the ballast resistor?

i did take the ballast of including the resistor. do i have to wire it to the + side of the coil ?

[jesus]

15 minutes ago, siteunseen said:

Sounds like the fuel filter is running dry to me.  Runs until it's emptied.  Try clear filter after the filter but before the fuel rail.

My crudded up fuel tank did the same.  After it sat and the debris fell to the bottom it would run about one block then die out.  Took the hose off the filter outlet and blew into it until I heard bubbling in the tank.  Hooked it back up and drove it home, many times.  Then I figured it out.

i dont know  about that because when it dose decide to turn on it dies as soon as i touch the peddle it dies. but it also takes a while of cranking 

[jesus]

4 hours ago, JSM said:

You said you have fuel, but how is the pressure? How long was the car sitting before you started working on it? 

not long the last owner swapped the engine but i started to get this problem after i got it running  

[siteunseen]

Something currently talked about, check the vane in the AFM.  Its under the black box.  Makes sure it moves freely and also pop off the black cover on the TPS.  Make sure it's not stuck on the throttle Idle contact, the contact closer to the rear of the car.

Spider webs and moisture cause problems on those components.  Have you washed the engine bay lately?

[Zed Head]

19 hours ago, jesus said:

 gm control module

 it only runs for a few seconds then shuts off

 when i get it to run if i touch the gas it shuts off right away

1975 280z federal

i get spark and fuel 

Sounds like really low fuel pressure or the AFM is not connected.  Running on cold start valve fuel or dribbles from the injectors.  When the throttle is touched it leans out and dies.

Could be that the EFI system is not even powered.  No injection from the injectors.  The CSV has a somewhat separate power supply.  Different pin from the EFI relay.

hav to get of of the pone and find a compter

[jesus]

1 hour ago, siteunseen said:

Something currently talked about, check the vane in the AFM.  Its under the black box.  Makes sure it moves freely and also pop off the black cover on the TPS.  Make sure it's not stuck on the throttle Idle contact, the contact closer to the rear of the car.

Spider webs and moisture cause problems on those components.  Have you washed the engine bay lately?

i have power washed it when i first got it that was about 3 months ago but it ran good for a bit 

[jesus]

1 hour ago, Zed Head said:

Sounds like really low fuel pressure or the AFM is not connected.  Running on cold start valve fuel or dribbles from the injectors.  When the throttle is touched it leans out and dies.

Could be that the EFI system is not even powered.  No injection from the injectors.  The CSV has a somewhat separate power supply.  Different pin from the EFI relay.

hav to get of of the pone and find a compter

hmm i will look into the fuel see if i get good pressure the thing is i dont got any way of checking the fuel pressure 

[JSM]

Harbor frieght sells a kit. Not the best gauge but has everything you need.


Sent from my iPhone using Classic Zcar Club mobile