not getting enough fuel, I think

[milesz]

My 280zx turbo is running funny since this weekend. I replaced the fuel pump and fuel filter and it is still running lean. I used another ECU and still running the same. I checked and cleaned the plugs and still starving for fuel. I am now think about the O2 sensor. Oh, it seems to run good at startup but shortly after when I give it gas it like it starving for fuel.

 

I could really use some advice.

[twoeightythreez]

also check for a clogged cat. If it's partially clogged you will idle and drive fine but when you get on it, you won't have any power, and the engine will surge like it's running really lean, but you'll have black smoke coming out the back like it's too rich. I found that out on mine, kept leaning out the maps and it would NOT lean out, finally pulled the exhaust and checked ,and voila! Clogged catalytic converter. Everyone kept telling me it couldn't be it since the car seemed to rev fine (which it did, until you hit about 4500 rpm or so)

[BRAAP]

Do you have an RB conversion in your 280-ZX or is it the original Datsun L-28ET?

 

In regards to the L-28, (could apply to the RB as well), are you sure it is starving of fuel and not being excessively fueled? If is it being excessively fueled, evidence will be black smoke from the tail pipe and black sooty spark plugs. I say this because a very common typical issue is the connections for the OE water temp sensor commonly have issues, corrosion, etc. If the ECU sees infinite resistance, (an open water temp signal to the ECU, not to be confused with the water temp sender for the temp gauge, separate sender all together), the car usually starts fine, but as the engine arms up, it runs worse and worse from being pig rich, i.e. too much fuel.

 

If it is starving for fuel, look for vacuum leaks between the Air Flow meter and the intake manifold and check all other vacuum lines that come off the intake manifold.