280z ecu

[chris frizzell]

hi can anyone help haveing a problen with my 280z project .the car has been fitted with a later 280zx engine and i think it needs a new esu. Do i go for a 280zx or 280z not sure what is fitted to the car . the car has spark fuel but fuel pump will not run .if anybody has any ideas . many thanks chris

 

[Jimbo]

put a manual live to the pump and see if it works then.

 

[chris frizzell]

done that. no joy got power to the ecu but nothing after that put all new injectors on which have power but may not be firing in time tested all terminals but not sure if its the correct ecu can you have a 280z ecu with a 280zx engine?

 

[Jimbo]

no idea but the pump isnt going to be coded to an ecu so should run if you put power to it.
if not it sounds like you have a duff pump

 

[chris frizzell]

pump will run when i put another battery to it but car will not start . but i think its the ecu as it sends a current to the pump to start through the air flow meter its doing my head in

 

[SacCyclone]

Hi Chris, I don't know anything about the ECU's on 280Z or ZX's but I have a mate who has probably 20 or so ECU's from various years of Z cars. If you end up finding out what ECU you need I might be able to get a used one for you.
Mike

 

[Huw]

Chris

The ECU has nothing to do with the fuel pump. The pump is operated by the current being supplied from the fuel pump relays (there are two on a 280ZX) which is energized when you put the ignition switch to 'start'. So check the fuel pump relay and the connections to it. If the pump cuts out when running check the connection to the oil sender. The oil sender can cut the supply to the pump if it suddenly sees no oil pressure.

To test your ECU you will need a 12v 3w bulb on some fly leads. Do the following:

1. Disconnect the electrical connector to the cold start valve (the injector just after the throttle body)
2. Disconnect the connector to number 1 cylinder
3. connect the lamp across the number one injector harness plug
4.Crank the engine

If the bulb flashes when its cranking, the ECU is good. If it doesn't then its junk.

Huw

 

[uk66fastback]

And there are ECUs going cheap on another thread! (if it is junk)

 

[Mr.F]

280ZX and 280Z ECUs different. Also, early and late 280ZX ECUs different and have altered ancilliary parts to suit - ballast resistor to the injectors is a different design for example. Also ECU is matched to auto or manual car.
As noted, fuel pump operation is externally controlled by relays and should prime the system then stop, restarting the pump once the engine fires / has oil pressure - separate terminal on the 280ZX oil pressure sender.
If you have a part number on your ECU, I should be able to cross reference it for you.
One further thought - there may be a flying lead on the ECU to receive a "run" signaal from the coil / distributor. Is that connected? Nothing works without it....
Is the ECU power relay working OK? i.e. is the ECU getting a correct set of power signals? This relay is a common failure on the 280ZX. Also is voltage strong? Low battery voltage will cause the ECU to misbehave.

 

[Huw]

Is the ECU power relay working OK? i.e. is the ECU getting a correct set of power sinals? This relay is a common failure on the 280ZX.

That’s good to know Mike