I'll work on what you said. I have only a Haynes Manual. I'm assuming "FSM" is a field service manual. Are they available at, maybe through Nissan?

Sometimes the Haynes manual confuses me. It states that if the gas pressure is bad, the regulalor needs to be replaced and then it says if the gas pressure is bad, I need to replace the puel pump.

Although the Haynes manual is good, it obviously has mistakes, probably from covering some earlier or later cars that don't apply.

FSM=Factory Service Manual. They're not available any longer through Nissan. I got mine on eBay. I also have the Haynes (810/Maxima 77-84) but I don't use it because as you say it can be somewhat vague. To check the fuel pressure, remove the hose from the top of the fuel filter and connect a pressure gauage between the fuel filter and that hose. I made my guage with parts from the hardware store. The manual says 36.3 psi but I've always used the 36-38psi range as acceptable. Once that pressure is established (should be instant upon start up) it should remain when the engine is turned off. If not the pressure is bleeding down genereally due to a bad check valve. Worst case scenario be a bad diaphragm in the fuel pump but then the running pressure would also be low.

Here's a 1978 FSM on eBay right now. There's a couple of others but this is about as much as I'd pay for one:

http://cgi.ebay.com/ebaymotors/1978-78-Datsun-810-Shop-Service-Repair-Manual-orig_W0QQcmdZViewItemQQcategoryZ6762QQitemZ7984825958QQrdZ1

By the way, that picture of the 810 on page 4 of the Haynes manual is exactly like mine when I bought it except whoever first bought it opted for the cast aluminum fancy-like wheels.

Thanks, Stephen. I just ordered the FSM from e-bay. Hopefully it will help.

Thanks, Stephen. I just ordered the FSM from e-bay. Hopefully it will help.

It's head and shoulders above the Haynes manual. I details test procedures for relays, switches, and sensors, and has many other things not covered in the Haynes. If you ever see the Clymer Datsun 810 1977-1980 shop manual it's also worth having but the Nissan book is the best. I have always prefered Clymer and Chiltons over Haynes.

Hi I have only just read the end of this post, does the fuel pump keep running when the engine cuts out? Does the pump relay rely on the oil pressure switch to keep it the pump running?

Colin :rambo:

Concerning the 'fuel pump' -- You may have just started something.

Concerning the 'oil pressure switch' -- That's over my head until I learn more.

Well, I went through my stuff and found a couple of good check valves. Let me know if you want one.

Well, I went through my stuff and found a couple of good check valves. Let me know if you want one.

I replied via 'private message'.

Stephen, it's probably a good idea if we hold off for a few days. I have to check the fuel pressure as soon as can get my hands on a pressure guage and then wait until the bitter cold and nasty weather gets better. Forecasts say middle of next week should be better except for possibility of some rain.

harbor freight now carries one, cheap.

harbor freight now carries one, cheap.

Check Valve or Pressure Gauge?

After looking at their web site, I assumed you were talking about the pressure gauge but I couldn't locate it.

PS guage. There's one in-store here.