78 vs 75 : Using the EFI Bible trouble shooting Section

[JSM]

Searched for 'EFI bible 1978' and 'EFI bible 78' but found little information.

 

I'm curious to the test performed on page 45 for the circuit testing. The EFI bible was based on the 75 and I know the 78 is a unique harness unto itself. Are the pin's the same on the harness for all the test?

 

I'd hate to start testing with 1975 results only to find out they were wrong based on 1978 design changes.

[Tennesseejed]

Searched for 'EFI bible 1978' and 'EFI bible 78' but found little information.

 

I'm curious to the test performed on page 45 for the circuit testing. The EFI bible was based on the 75 and I know the 78 is a unique harness unto itself. Are the pin's the same on the harness for all the test?

 

I'd hate to start testing with 1975 results only to find out they were wrong based on 1978 design changes.

 

Page 45 of my copy of the bible is the list of circuit tests titled "Circuit Testing."

 

Typo???

[JSM]

I'm not sure on the confussion of my question. Let me retry. I have a 1978 280z, the EFI bible was written towards a 1975. I know the wiring harness and possibly the ECU are different.

 

Is the 35 Pin Control Unit Connector, Plug that goes into the ECU different for a 78 than prior years?

 

Pages 45-71 are used to trouble shoot and check specific components on a 75. Are these checks (tests) the same for the 78 due to the harness differences? As an example, I was pretty sure the AFM were different on the 78 then prior years?

[Tennesseejed]

JSM, I don't have the answer to your question. I'm just trying to be helpful.

 

Your OP said "test" on page 45 so I thought you were referring to a specfic circuit test. Perhaps you meant "tests".

 

As you know, Pin 35 on the ECU is a ground (for '75 anyway). You can easily confirm this with a mulitmeter to see if you measure little or no resistance from Pin 35 to chassis ground.

 

I do not know for certain, but seriously doubt, that the L-Tronic FI system was radically changed between '75 and '78.

 

Is there a specific test you are needing, or are you just generally asking if the November 1975 EFI Bible will cover your '78?

[JSM]

JSM, I don't have the answer to your question. I'm just trying to be helpful.

 

Your OP said "test" on page 45 so I thought you were referring to a specfic circuit test. Perhaps you meant "tests".

 

As you know, Pin 35 on the ECU is a ground (for '75 anyway). You can easily confirm this with a mulitmeter to see if you measure little or no resistance from Pin 35 to chassis ground.

 

I do not know for certain, but seriously doubt, that the L-Tronic FI system was radically changed between '75 and '78.

 

Is there a specific test you are needing, or are you just generally asking if the November 1975 EFI Bible will cover your '78?

 

No worries at all. Appreciate any clarity. Your last question is my question, neatly put into one sentence! I see even my description "35 Pin Control Unit Connector" was understood as Pin 35.

 

I wanted to run through all the tests as the car runs okay.

[BRAAP]

To the question posed, "is the '78 EFI pinout different from the '75-'77 pinout".

 

Answer to that question is they are totally different! The pin outs listed in the EFI bible will not work for the '78. The '78 uses the same physical connector, but the pinout, wiring harness, relays etc are totally different and unique to the '78 only!

 

The principles the EFI bible covers still apply, but you must convert the actual pin-outs to match the '78 for diagnosing a '78 Z car EFI.

 

Here are some diagrams of the '78 EFI wiring if it helps;

http://forums.hybridz.org/index.php?/topic/89575-swaping-78-l28-efi-into-72-240z-wiring-help-needed/

 

 

Hope that helps,

Paul

[JSM]

Thanks Paul. I had feeling it would be different. I didn't want to start testing on the 78 wondering why I was getting different results than those listed in the EFI bible.

 

I would have really screwed things up!

 

So for the future and those that may stumble across this thread, the diagnostic tests specicfically on Pages 45-71 in the EFI bible are only applicaple for model years 1975-1977.

[Tennesseejed]

I stand humbly corrected.

 

Glad BRAAP could send you in the right direction. Good luck.