what am i missing? please help

[arally1]

I posted this in fuel forum but didn't get any response, and i have to get my z on the road. My 1977 280z 4sp sat for a long, long time. Had a fuel problem years ago, removed the tank had it boiled and relined but still never ran. At present I bought 2 new fuel pumps, and finding out the universal pump I got was to weak(wasted $150) bought the proper one then discovered the tank outflow line is plugged) So I put a connector on the tank drain plug and am drawing gas from there, it drove fine for 6 to 10 miles, but consistently has got worst, now I goes less then a mile and starts acting up. The new pumps giving me 36 lbs past fuel filter where I installed a fuel pressure gauge and ran it so I could view the pressure and monitor it constantly. The car starts fine and drives for 10 -12 minutes then as I'm driving it stalls but doesn't die, kinda like its out of gear, pressure remains good, I clutch it and rev it, pressure seams to sputter a bit if I keep revving. I then turn car off for a moment and it starts right up and drives again. I'm sure I need to give more info but am at a loss at this point. It also back fires on occasion from the AFM I think.

I gotta get this car outta here, Its a divorce thing, car or wife,

I chose car, besides I had it longer then I had her.

thanks for any help

[MEZZZ]

In my very limited knowledge, it might be the water temperature sensor. It actually richens the mixture of air/fuel until the engine arrives at normal operating temp, gradually allowing for a leaner mixture while the engine warms up. Do you have a copy of the Factory Service manual or the Fuel Injection Book?

If not, do a search on here for links to download them and read up. There are diagnostic tests you can find in both manuals that might help you pinpoint the problem.

[arally1]

thanks for the info, i did get the manual and will look into it.

[sblake01]

I clutch it and rev it, pressure seams to sputter a bit if I keep revving.

You still have something clogging the fuel system. If you have a way of drawing fuel from some other source like a gas can (I use a pressurized fuel injector canister cleaner), do that and see if the fuel pressure still fluctuates. I bet it won't. Sounds to me like perhaps the shop didn't do a proper job of cleaning the tank. Edited August 31, 2008 by sblake01

[hls30.com]

I believe Stephen is right on it, sounds like junk in the tank...

There is a copy of the EFI manual in the archives, if you can't find it, PM me an email address, and in the next day or two I'll send it to you.

Will

[sblake01]

Here are direct links to the 1977 280Z FSM: http://www.xenons30.com/files/FSM/77_datsun_280z.pdf.gz

And to the EFI Manual: http://www.atlanticz.ca/zclub/techtips/efisystem/280zfuelinjectionbook.pdf

Keep in mind that while the EFI manual is helpful, it's actually geared towrds the 1975 280Z.

Edited August 31, 2008 by sblake01

[MEZZZ]

You guys are the experts He did say that his fuel pressure gauge past the fuel filter is running at 36psi and he monitors it constantly. Would his pressure still be at 36 if he has junk clogging it up? I checked mine and it is an even 36 constant past the filter, I was relieved that I didnt have to drop the tank, now maybe Im not so sure.

[sblake01]

I based my conclusion on this:

I clutch it and rev it, pressure seams to sputter a bit if I keep revving.

[arally1]

thank you ,- i'm kinda concerned it may be the tank, but can't find one anywhere, I didn't want to boil this one again, i think it may have varnish from the gas while sitting, although when i looked thru the tank, looks good i see the liner inside is clean, but maybe i missed something. so i guess i'll drop the tank and see, then post my findings.

I appreciate the help guys

[sblake01]

You stated that you 'Had a fuel problem years ago, removed the tank had it boiled and relined but still never ran.' Two things: if it was done years ago and it sat for that time with gas in it, whatever you cleaned out would just build up again. You use the terms 'boiled out' and 'relined'. Did you do it yourself or have it done?

[arally1]

I had it done at a shop that does this sort of thing. Also the exhaust is a bit rusty and may have a whole or maybe a blockage, I smell it when I'm in drivers seat with door open. Could this have something to do with my problem ?

Edited September 1, 2008 by arally1

[sblake01]

Doubtful. The exhaust, while it could cause performance problems, wouldn't have any effect on the fuel pressure. I'm afraid the tank will likely have to be done again.