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Discrepancy between EFI Bible & FSM?

Old 09-08-2015, 05:07 PM
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Discrepancy between EFI Bible & FSM?

Hi Guys,
I'm having issues with my 1978 280z (manual 4 speed). It has some random starting issues, but generally starts & idles fine. While driving though, it's go almost no power. I tried to drive it work and it maxed out at 70 mph with my foot on the floor, and slowed down on hills. My dad came over to help me check the timing and I started it once and it sputtered and died after a minute then failed to start afterwards (first time ever doing that). Since then I've been able to start & drive it like before.

But I decided to go through the ECU pin checks per the EFI bible & FSM and noticed that they don't quite agree. My car is missing contacts on the ECU connector at pins 11, 20, & 26. The ECU is missing pin 21.

According the EFI Bible, Pins 20 connects to a relay while Pin 21 connects to the Cold Start Valve. Pins 11 & 26 are not used.

According the FSM, pins 11, 20, & 26 are not used. Pin 21 connects to the Cold Start Valve.

It seems like I should definitely have Pin 21 to connect to the Cold Start Valve. I'm not sure if Pin 20 is actually connects to the relay or not, based on the differences between the two sources. Has anyone seen this before?
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Old 09-08-2015, 08:58 PM
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There are various EFI wiring changes between the 76, 77, and 78. The EFI bible was probably compiled from one FSM. Just use the FSM for your car.

You can also quickly identify wires by doing ohm (continuity) tests.
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Old 09-09-2015, 03:45 AM
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Yeah, I was hoping it was something like that. That means I don't have a relay issue (hopefully), but I should still have Pin 21 for the Cold Start Valve.
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Old 09-13-2015, 01:27 PM
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You mean the EFI manual revised 1975?
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Old 09-14-2015, 09:47 AM
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The '78 is different than all the others. I think your problem is the fuel pump was weak and has now failed completely. Check your fuel pressure before your pull your hair out. Make sure you got the '78 manual.
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