Ugly Duck wrote:
Will it run if you jumper the pumps? Connect fuse 5 to fuse 7 (or is that 4 and 6? 3 and 5??? Nothing's gonna zot if you get it wrong) and give it a crank.
Edit - wait, hold up. I don't know if you've changed the fuel pump relay wiring. If grounding the ECU fires the pumps, you must have. Your relay still requires a tach signal though, no? The above jumper test is how we got your car to fire before.
The main relay handles all of the switched power to the EFI...all of it. It's a DPDT relay that separates the engine side into two components. One side handles sensor inputs (MAF, CTS etc) and the other side fires the active side of the EFI (pumps, injectors, IAC). The relay is triggered by the computer through grounding. So when wired, we ground the side of the relay that runs the pump, fires the injectors and idle etc and it fires. This is covered in the basic ECU power testing.
So we've verified that all aspects of the wiring is fine. There are two problems as I see it:
1. The side of the wiring that deals with the pumps, injectors etc is not getting a ground signal. So we can jump the harness and verify that the wiring is fine, but the computer is not helping.
2. The power stage signal test (as per Bentley) says that the signal coming from pin 16 on the computer. This signal should be coming from the distributor hall sensor and sending an 0 - 2 V pulse to the ignition amplifier (this then triggers the coil). The power test is to disconnect the amplifier and test for an oscillating pulse on pin 5. We receive a constant voltage of 0.2 V. We've verified the dizzy wiring and it's connected and should be fine. I don't have an oscilloscope, so can't test the pulse from the Hall sensor and don't know how to verify that it's fine. What we know is that it worked the last time we fired the car.
At this point, we've gone over it from head to toe and simply can't come up with why these two issues don't work.
Does anyone know how to check the Hall sender? That's about all we have right now.
I'd post this over on TBrix, but the signal to noise would be pretty high...Greg and I know how to read a wiring diagram.