Nate Labonte

I have a 1977 280z with fuel injection and it will run and somewhat drive but i tried tuning it and now it will idle and i can rev it up but then after about a minute i will try to rev it up and it will die down and stall it has a new cap and rotor, wires, and plugs and new tubing for the fuel rail but i cant seem to figure out what the problem is i really need some help figuring out whats wrong

theramz

You need 35 psi fuel pressure constantly. It can be as simple as a fuel filter, there is one before the pump, one in the engine bay and one that is not even mentioned in the fsm, it's in the intake side of the pump. The pump may be weak or the fpr is bad. Simply put you are running out of gas.

Nate Labonte

ive changed the one in the engine bay where is the one by the pump

jimbolo619

If you have the stock fuel pump it is/should be on it they usually call it the damper. Correct me if im wrong theramz

Steve260Z74

The damper is to prevent fluctuations in fuel pressure (EF-58). If that is faulty, I would guess that you would have surging or stalling.

The FSM only identifies one fuel filter, downstream of the fuel pump. The damper might have an integral filter, though.

I also checked through the parts catalog at CarPartsManual.com - Online Parts Catalogs for Classic Cars (great site to bookmark), and in searching for "fuel filter", I only found the fuel filter in engine bay and the filter for the emissions control.

The Nissan part number for the damper is 22675-N4205. Courtesy Nissan will get it for you for $95+shipping. If you have a Nissan dealer close to you, you might want to see if they will order it by the part number.

theramz

The filter I'm talking about is actually a cone shaped strainer in the intake port of the pump. It catches all the big chunks from the tank. There may or may not be a filter before that but I've seem filters just before the damper after the pump. You really need to check pressure with a gauge while runnig because even a weak pump will get enough static pressure at idle or engine off.

Nate Labonte

could i use just any fuel pressure tester to test the pressure or is there a certain one

Steve260Z74

Get one that goes up to around 50 PSI. That should give you enough resolution to gauge the pressure. Be sure to depressurize the fuel rail, firsit. The procedure is in the FSM.

jimbolo619

[QUOTE=Steve260Z74;324446]The damper is to prevent fluctuations in fuel pressure (EF-58). If that is faulty, I would guess that you would have surging or stalling.

The FSM only identifies one fuel filter, downstream of the fuel pump. The damper might have an integral filter, though.


I'm sure the manual states that the damper does have an integral filter in it. Ill look into it.

280zWraith

Several things need to be checked just to make sure you are good:

-Fuel pressure (~36 psi). I bought a gauge from O'Reilly's, so nothing too special, but it works great.
-Cylinder compression (~170psi)
-Spark in all cylinders
-AFM functionality (troubleshooting info can be found in the FSM or the EFI bible.) This was tripping my car. Also, make sure there's less than 1 ohm of resistance from the body of the AFM to the negative cable connected to the battery. If there's more, check the wire that's supposed to be grounding the AFM. It runs underneath it and is tied to a bolt on the plate which connects it to the frame. Also, make sure to clean any rust from the plate, frame and/or bolt.
-Vacuum leaks (these cars HATE vacuum leaks.) Check all your hoses.
-CLEAN ALL YOUR CONNECTORS!!! I used Deoxit D5, a pick and a flat needle file. Go through all the connectors on the EFI harness and make sure you clean them and the terminals they come in contact with. To get rid of any excess cleaner I used a bottle of compressed air, like the ones used when cleaning electronics.
-Get a stethoscope and while the car is running, make sure all your injectors are firing.

Hope these suggestions help getting your car back on the road.