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L28ET not getting injection or spark.


TT2STConvert

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So a few weeks ago, before I had the fuel system finished, we cranked the engine with a plug out and observed visible spark. I finished the fuel system last weekend, cranked it, and it wouldn't start. Pulled a plug to check spark, no spark. No hiss (nor smell) of fuel spraying into the cylinder either.

 

My background is almost exclusively in the Z32TT, so I don't even know where to start looking here. The only thing I recall changing/moving is the ECU (I mounted it), but I checked the connectors there and they seem tight. I live 250 miles away from the car and only get to work on it every other weekend or so, so I was kinda hoping someone with experience with the L28ET could give a few ideas of where to look when I go back next weekend. I need to get this thing running before snow starts so I can bring it home. Engine, harness, and ECU are all 1983, and the LED on the ECU does light up.

 

On a different note, when I first fired up the fuel pump and the system started getting pressure, there was a strange rhythmic howling noise coming from the fuel rails... is this normal when an engine's been sitting for a long time? It went away after a few minutes, but it was a sound I had never heard before. I'm gonna order a mechanical fuel gauge to make sure the system is pressurizing properly, but when I pulled the return off to ensure fuel was flowing through the system, it seemed to have adequate pressure.

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Besides getting the 3 plugs back into the ECU, you also have the 2 other connectors (Labeled "2" and "3" in the FSM Turbo Circuit Diagram) plugged back together? One of them feeds the Coil and ignitor... (You used the coil harness from the '83 ZXT?) The ECU controls the ignitor on the signal from the distributor so double check the 4-pin dizzy connector to the ECU Harness...

 

You really haven't given much background, so I'm going to ask some stupid questions - The ECU gets power from 2 sources: Both are connected to battery through fusable links - one Green, one Brown? (Brown powers EFI Relay, Green powers Injectors and ECU Injector circuitry)

 

You know your injectors open? The L28ET injectors make a distinct clicking noise and it's easily heard if you know what you're listening for. (Mine were original, had been sitting unused for who knows how long and were mostly all stuck shut...)

 

Electrical connectors seem to be a weak link on most Z's - mine definately were... Double check / clean your connectors.

 

The stock L28ET ECU controls the fuel pump like this: At IGN on, it runs the pump for 5 seconds and then shuts it off. It won't power the pump again until it gets signal from the AFM that air is moving through it. (engine cranking or running)

 

You've double checked the fuel feed and return to make sure they're connected correctly? I made the rookie mistake of having them backwards once... The only thing I could think of that would make noise is the fuel regulator on the injector manifold.

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