When should fuel pump begin operating?

[sblake01]

It's the nipple on the pump that screws into the outlet

[sblake01]

Here are the 280z fuel pump operation charts. The pumps are actuated differently depending on year but at no time should the pump run until the car has started.

75-77

78 (Note that there is no mention of AFM contact points or fuel pump relay)

Sorry, you must have inaccurate or incomplete information. My engine, the wiring, and all the relevant literature I have all confirm a set of contacts in the air flow meter. Otherwise, I would not have said so.

Either TomoHawk is mistaken or he has a quite special 78.

Edited October 24, 2008 by sblake01

[Jeff G 78]

It's the nipple on the pump that screws into the outlet

Great. I will look up the P/N using my handy dandy microfiche and order one up. Thanks Stephen.

[Jeff G 78]

Either TomoHawk is mistaken or he has a quite special 78.

Every now and then some weird things happen. For example, I have a factory externally oiled cam N-47 head on my Z. It must have been an early '77 head. I don't think there are too many like it floating around.

I bought if from a guy in San Diego about seven years ago. Apparently it was a brand new take-off head that had been sitting on a shelf since 1977. It came complete with the cam and valvetrain parts. The cam didn't even have a wipe pattern yet. The seller said it once belonged to one of the factory race teams.

It *might* be possible for TomoHawk's car to be a really early '78 or something.

[sblake01]

As I recall, his VIN is somewhere in the 434XXX range which would put it well past the 'early 78' time frame.....I only mention it becasue he came on so strong about it and hasn't bothered to reply since......which seems to be his norm.

Edited October 24, 2008 by sblake01

[Walter Moore]

Sblake,

Thanks for the information from the manual. I am actually impressed by the 78 system. Using the Alternator as a backup for the oil pressure switch is a really good idea. It must really cut down on nuisance stoppages.

After installing my electric pump on my 71 I had a couple of instances where the engine stalled for undetermined reasons. In one case I had to by-pass the oil pressure switch to get it to run so I could drive home. But then I checked the switch and it tested fine.

I am still running a points style ignition, and have the oil pump powered by the "hot" side of the ballast resistor. I eventually realized that if the oil pressure switch made while the engine was still cranking the voltage to the pump dropped to 6V. (Ballast resistor is bypassed while cranking.) In that case, if there was no fuel in the lines the pump would never pressurize the system and the car wouldn't start.

I added a diode backwards across the ballast and that fixed the restart problem. The stall problem I have never tracked down. I can't make it happen so I have no idea what causes it. It has only happened twice.

[sblake01]

Not a problem. I try to give info that is as accurate as possible based on my own experience and research. I use a lot of scans to verify what I say. I've been around these cars a long time especially the EFI cars and I feel like I know them pretty well. Have you ever seen me ask for mechanical advice? It kind of bothers me when I post a possible solution and someone follows it up with something the is either erroneous, unrelaed, or just plain wrong, which somewhat confuses the issue, and then won't come back and admit it. If it was the first time I wouldn't be so fired up. I've got nothing else to say about this or I'm sure I'll end up getting an email from Mike or one of the other administrators.

Edited October 25, 2008 by sblake01