Where is the pressure regulator?

[Guest HellTriX]

Hey guys, I just got me a 280z (Finally) before I swap to a v8 I would like to paint the car and redo the interior, but while I am doing that I would like the I6 to run decent. I noticed the guy that owned the car before me put in an electric fuel pump which is mounted in the engine bay and wired to the coil for power. It is plumbed directly to the fuel rail. The other tube to the fuel rail appears to run back to the tank. I assume one is a feed line which is what this new pump is hooked to and the other is the return line, but where is the pressure regulator? The car runs so rich its burns my eyes and makes em water to hell. Then if I give it too much throttle when driving the car starts to run on like 4 or 5 cylindars and then stalls and I have to restart the motor. I figure its getting to much pressure. I think the stock pump got plugged or burned out so this guy added an electric pump just to get by, but I would like to do it right now and get it to run better.

 

Thanks

[Nigel]

Is the 280 still fuel injected, or has that been replaced with carbs? If it's injected, then the pressure regulator should be on the fuel rail right between cylinders 3 and 4

 

Also, most high pressure EFI pumps don't like to be mounted that far from the tank. They're not too good at pulling fuel. Perhaps there's a surge tank mounted near by?

 

And no filter between the pump and the tank? The PO sounds like a bit of a hack...

 

Nigel

'73 240ZT

[Guest HellTriX]

Well I think its still fuel injected. I am not to sure. I have never seen anything like this setup before. It has two peices carbs/injector bodys, each feeding 3 cylinders. and there are little chanisters with a screw top on them that when I pull one out is like a rod with some type of metering device or so it looks like. With either oil or really sticky fuel on it.

They could be carbs I dunno, I am gonna start taking things apart and learning everything but I dont want to get too carried away and make things worse.

 

I am gonna try to get to the fuel pickup in the tank and check for crap in the tank and pickup screen, and I will trace up the fuel lines and replace any filters. I will check voltage to the original pump, try to flow test it to and replace if nessasary. I dont see a pressure regulator anywhere near the fuel rail. There are 2 lines one going to each carb/injector, and the 2 steel lines that make up the fuel rail are plumbed into a jerry-rig fuel pump and to a fuel line that runs to back of car somewhere.

 

So its my thought the fuel regulator was removed and now the car is flooding cuz it runs so rich and blows black smoke I was told.

 

Thanks for the post, I will post again when I have more info. (going out to tweak on it now)

[Guest HellTriX]

Ok did some working on it today.

Backed up on ramps slid under her rear, and found the bracket where I assume a stock fuel pump used to reside? No longer there. 2 tubes from gas tank to hard lines running to motor.

 

One hard line plumbed into electronic fuel pump which is only pumping 2.8-3 PSI low volume (not even a half a cup of fuel in a minute with no load)... this feeds one of the hard 2 hard lines that run above the intake. Which is feeding both Carbs. They sure look like carbs to me. Pulled the cap off one of them and found a large spring loaded piston and bore with a needle comming out of the piston and cap lid thing. The other hard line rail feeds back to the tank I think so that would mean no fuel pressure?

Guess the carbs have to vacuum there own fuel in.

But I turned the ignition on and let the fuel pump go for a bit and noticed fuel was leaking/draining out of the bottom of the front carb and out of the thing beside it where the fuel line hooks upto beside the carb. I am not sure what that is yet, but there is no hose on the top of it and fuel was comming out of that too. The other carb didn't leak.

 

If any of you can give me some more info or point me to the right forum since I guess I have carburation. I am tempted to build an adapter to hook up my 4 bbl edelbrock to the two flanges for the original carbs

 

Thanks

[Guest jt240z]

Do yourself a big favor and have both carbs rebuilt. Go to this site:

 

http://www.ztherapy.com/

 

Learn about the SU's and if you decide to have them rebuilt, they will do a good job.

 

 

If you don't know the difference between a carb and fuel injection, then I wouldn't attempt to take them apart and fix them till you do a lot more learning. I'm not trying to be harsh, just trying to cut down on your frustration factor. Messing with leaky carbs can get down right dangerous. It's a good way to loose you car completely.

[Guest HellTriX]

Yeah I was just debating here while reading the forums if I even want to deal with this..

 

I am building a 1966 Impala currently http://ecahost.com/Impala and I found this 280Z for too good of a price to pass up. MY first thought when I saw this car was "boy that would be awesome with a v8 and TH400 that is sitting in my shop.

 

I just wanted to get this thing running ok while I sand blast the body and interior floor boards. So I dont think I really want to rebuild the carbs since I plan to drop a v8 in it very very soon.

 

I am used to chevy so these webers looked new to me, once I pulled off the covers I knew they where carbs, but I didn't look really good before I posted I should have known by the linkages but I just took a 30 second glance at everything.

 

I thought about building an intake that I could mount my Edelbrock 600cfm carb too that would adapt to the mounting flanges that the webers bolt to. It would be crude but I think it would provide decent metering of air/fuel if I jet the carb right. If it ran good enough to make 10 block trips to the parts store thats all that I really care about till the V8 is ready.

 

Thanks for the input, I book marked that SU site.

BTW, whats SU stand for? heh