theramz

If you have a bad connection to the oil pressure switch the ECU will shut the FP off.

snwbrderphat540

I am getting great oil pressure readings. New fpr and absolutely no change. Now I remember first time I drove the car prior to this engine rebuild I did one quick pull and it boosted hard. Then ran like it does now,.shitty. so I thought maybe I blew the rings but now I see its fuel pressure on thus new motor. So I'm wondering if there was enough suction in the tank and I ruptured the sump line n now I'm sucking air in the tank as well as fuel. No reason it would work fine once then after one pull the fuel pressure is crap.

snwbrderphat540

Oh and I also have a super odd issue, everything was fine body harness wise prior to this motor rebuild. Nothing was touched other than the basic electrical connections necessary to pull a motor and place one back in, but now after the rebuild when I hit the brakes the brake lights come on but so des the back lighting on the dash instruments. Lol. Wtf. I touched nothing that would cause that....

snwbrderphat540

Also if its a turbo swap into an s30 how would the ecu be getting a rearing to do that. And should the pump not work or at least at idle hold normal pressure...

JSM

This is why I suggested building a little tank with its own pump. This way you can verify 100% it is a fuel issue and that everything else is okay. Just a process of elimination.

snwbrderphat540

Yes yes I will....

JSM

I totally forgot I had this. You can see how I did what I was suggesting at the very begginning of the video.

http://www.youtube.com/watch?v=bSIWZP5C1pY

snwbrderphat540

Haha i knew what you meant. I don't have enough fuel hose lying around and was to busy making the s2000 protected from salt. I did have enough hose though to remove the connection of the fuel pump from the tank and stick some line on it and sink that into a fuel canister. Same issue. N the gas siphoned out of the tank well so I at least know the tank is healthy. While under there I could hear the fuel pump still pulsating. Which is why I initially suspected it to be scavaging air in the tank. When then disconnected that line to stick back on the tank I got some real dirty backflow. So I'm now suspecting simply dirty filters. However ill still be trying your idea Jeff as well.

theramz

Not if it is a loose connection. Your guages are dampened so you might not see a drop in pressure. On the early cars (pre '78) the afm must be open after start or the fp relay cuts off. "78+ it was wired through the OP sensor. If the pump is hot wired it won't matter.
After your last post it seems you may have a clog between the tank and pump.
You say you have a clean tank and lines but maybe a pos got from the return line into the tank and made it's way to the filter.

snwbrderphat540

I'm suspecting that too. Gas was siphoning out of the tank by just pulling the line and cleanly so its all clear and solid in there. Which is a relief. But back flow from the pump end was very dirty. And for it to pull hard once and then not, I'm thinking a pos got in there as well. But can't say for sure until I do more testing this weekend. Hoping it turns out to just be crap in a filter. Would be such a stupid yet simple problem...

Bleach

On the swap in my ZX I just ran the fuel pump on 12v all the time.
The manual says the switch to 9v at idle is only so the pump is quieter. Doesn't seem like it would hurt to have it on full power at all times. You have a return line.

snwbrderphat540

So there are two switches on the relay?

snwbrderphat540

That wouldn't make sense. It's a 76 relay. I just &ave the turbo.ecu fuel pump signal tied to the stock 76 relay/harness so.it should be either on or off full power

theramz

Now there's a clue. If the relay switches to 9 volts it might not be enough for the after market pump!

snwbrderphat540

How does the 9v output work? This is the first I've heard of this on a 76

JSM

And don't forget that harness is from a 78 too! Just to throw some more confussion in the mix!

snwbrderphat540

Ahhhh Dammit. Lol.

Bleach

Sorry, that info might be only for the 280ZX turbo... 1981-83.

JSM

No your right. The EFI harness is from an 82 ZXT and his body harness is from a 78. Darn car fire!

JSM

So 11 days have come and gone, what's the verdict!

snwbrderphat540

a video is worth a million words... jaw dropping

http://www.youtube.com/watch?v=yR4UJ...ature=youtu.be





but yes when I go and set the camera on the outside that pull back the car leaned out again and dropped power. The fuel filters are clogging up again. Had that tank cleaned so well but maybe the lining is getting sucked up. idk... but at least I know what the problem is.

the day before this i short shifted 1st and left a 75ft patch of rubber on the ground in 2nd gear on the roll... and this is on stock electronics lolololololol... might need to get some real tunning capabilities in this car and see what she can really do. eats gas though, absolutely eats it...

JSM

Yeah! About time.

theramz

Feels great when you finally kill that last bug. I say ft mpg. When you get a tune that will improve. You still have to burn X amount of gas per HP.
I've seen several cars get clogged from bad tank sealers. It comes off in globs.