280

I guess a 280zx afm works better than a 78... i switched them around and the car fired up. But when ever i give it throttle i get a cloud of black smoke.

its a 77 i do have power to the the ignition as per fsm test . The coolant temp sensor also reads out fine. The tps is opened and positioned as it should be. I just keep running around in circles with the fsm and troubleshooting.

Yes that is correct, the contactors are in the afm so i simply hold the afm flap open to run the pump with the ignition ON. So the problem isnt the pump anymore it looks as if its working fine. i thought i was losing pressure because of the pump. However now that i have fixed the prressure issue, I cant seem to get the car started. I crank it and it seems as if it turns over but dies again after a second or two. Im sure im getting spark and fuel. Im thinking its something I may have moved or something all the connectors on the manifold/head seem connected. What else could it be ?

Ok so the vacuum lines wouldnt affect the cars operation so long as theyre plugged? Anyways I found out that i had a clogged return line after the regulator therefore it was building backpressure. Now I have a steady 36psi after the filter but now the car doesnt want to start. It starts for half a second to 2secs but then dies.

Its not color coded but it should point you in the right direction http://www.atlanticz.ca/zclub/techtips/wiringdiagrams/76_280z_wiring.pdf

Im sort of remotely on the same boat as you. There is no filter inside the tank as far as im aware. There is a mesh filter right on the inlet of the fuel pump that gets clogged, it may also be on the hose connected to the inlet if it somehow came loose. As far as the coolant temperature sensor goes. You can do an ecu pin test to see if its working correctly. All u need is a temperature sensor ( a cooking one would do fine) to measure the water temp. Then you would take a volt meter and check the resistance i believe between the two pins.(cant remember exactly which two pins its in the efi bible or fsm) But if you need to go and buy those two things it would be just cheaper and going to your auto parts store and just buying a new sensor its only around 15 dollars. Then you would rule that out. Make sure your current or new sensor doesnt have teflon on the threads because it could prevent a good ground. Besides that Check and/or reconnect all your bullet connectors in the wires just to make sure youre connections dont have corrosion on them preventing them from making good contact. I am a noobie so im just telling you what i would do.

I went ahead and checked and turned the idle scew up so it can hold the throttle slightly open. The car turned on and died again. I hook up the fuel pressure gauge directly to the outlet of the fuel pump and it reads about 60 psi. I then hooked it back up after the fuel filter (in the engine compartment) and it reads around 40psi. The problem is that it slowly starts losing pressure. Is it suppose to do that with the car off? I think it also starts losing pressure when i start the car thats problably why the car slowly dies. I do notice I have 3 vacuum lines loose but i doubt that has anything to do with it. I will post pics of where the lines are lose if you guys can guide me as to where they go. and the third one comes out of the passenger firewall above the heater hoses. They all lead into the vacuum tank. But as far as losing pressure goes does that mean the fpr is bad? or the fuel injectors are leaking? I remember using a stethoscope and hearing all the injectors clicking intermittently .

So I decided to start a new thread under the fuel injection section because its not related to the electrical section where I resurrected a thread from the dead. 280, I realize this thread is several years old but this where i got at by >searching< Im having the the same problem. I had a buddy of mine put his finger on the inlet of the fuel pump and he only felt suction while cranking. I tested all the fusible links inside the passengers compartment and all have continuity. With the key on the on position I held open the afm flapper and the fuel pump ran. I dont want to crank the car since its night but tomorrrow morning i will test some more. With the fuel pump relay/injection relay and the ignition ON is the pump suppose to build pressure for a few secs and then shutoff before starting the car? Is this my problem? Zed Head, Your results show that the parts you tested work correctly. The fuel pump runs when cranking. When the engine starts, you let the key go, but the AFM flap is open now from air flow and the fuel pump keeps running. If the engine dies, air flow stops, the AFM flap closes and the fuel pump stops running. So no problems with your fuel supply to the fuel rail, at least from the fuel pump outlet. 280, Not exactly. Once I let go of the key from the "start" position and stops cranking the starter/engine the fuel pump also shuts off. Therefore the car dies after a few secs. The fuel pump is new and i added a new fuel filter. I had also added a clear fuel filter before the fuel pump but removed it and just stuck the inlet hose into a fresh clean fuel tank. I also have a fuel pressure gauge connected after the fuel filter. It reads about 38psi if i leave the pump running without cranking the engine. Zed Head, I had a similar problem where the air flow would not hold the AFM flap open far enough to get it off of the cutoff switch, so the engine would not idle at low RPM. It ran fine, just wouldn't idle. If the fuel pump keeps running when you hold the AFM flap open as you described, you should be able to keep the engine running by holding the throttle slightly open after it starts (which should open the AFM flap), or turning up the idle speed with the idle screw (same effect). If this works, then you might have a vacuum leak, which is letting too much air past the AFM flap. Find that or the adjust the fuel pump cutoff switch mechanism. My problem started when I advanced my timing. The engine needed less air to maintain idle speed so the AFM fuel cutoff switch started killing the pump at idle. I ended up bending the switch mechanism so that it would stay closed at lower air flow. You can see the cutoff switch and how it works underneath the black cover on the side of the AFM.

I feel this is getting more toward the Fuel Injection section rather than electrical so im going to start a new thread under Fuel injection and quote these last few things.

Not exactly. Once I let go of the key from the "start" position and stops cranking the starter/engine the fuel pump also shuts off. Therefore the car dies after a few secs. The fuel pump is new and i added a new fuel filter. I had also added a clear fuel filter before the fuel pump but removed it and just stuck the inlet hose into a fresh clean fuel tank. I also have a fuel pressure gauge connected after the fuel filter. It reads about 38psi if i leave the pump running without cranking the engine.

I realize this thread is several years old but this where i got at by >searching< Im having the the same problem. I had a buddy of mine put his finger on the inlet of the fuel pump and he only felt suction while cranking. I tested all the fusible links inside the passengers compartment and all have continuity. With the key on the on position I held open the afm flapper and the fuel pump ran. I dont want to crank the car since its night but tomorrrow morning i will test some more. With the fuel pump relay/injection relay and the ignition ON is the pump suppose to build pressure for a few secs and then shutoff before starting the car? Is this my problem?