running rich with a new fuel pump

[kelltainer]

I bought my car from a guy who had "fixed" a bunch of things on it already but it is runs pig rich all the time. I am a parts changer and can do basic diagnostics.

 

First thing I did was check to see if I had an exhaust leak, I have none, second I looked under the car at the fuel pump to see if the guy changed the old one. Well he did, he put a e8312 airtex pump on it; when i looked up this pump it is for a isuzu(one of the old turbo ones) and on the fuel pump itself it says max 95psi.

 

Should I get a fuel pressure regulator and hook it up to see if I am getting too much fuel? Then just regulate the amount of fuel? The shop I used to work at said the ecu should manually tell the car how much fuel it should be getting but I'm not so certain.

 

Any help would be great because I am tired of smelling like gas when I get out of my baby, lol!

 

O I drive a 79 datsun 280zx na.

 

Thanks Jeff!

[NewZed]

I bought my car from a guy who had "fixed" a bunch of things on it already but it is runs pig rich all the time. I am a parts changer and can do basic diagnostics.

 

First thing I did was check to see if I had an exhaust leak, I have none, second I looked under the car at the fuel pump to see if the guy changed the old one. Well he did, he put a e8312 airtex pump on it; when i looked up this pump it is for a isuzu(one of the old turbo ones) and on the fuel pump itself it says max 95psi.

 

Should I get a fuel pressure regulator and hook it up to see if I am getting too much fuel? Then just regulate the amount of fuel? The shop I used to work at said the ecu should manually tell the car how much fuel it should be getting but I'm not so certain.

 

Any help would be great because I am tired of smelling like gas when I get out of my baby, lol!

 

O I drive a 79 datsun 280zx na.

 

Thanks Jeff!

 

You mean fuel pressure gauge, right? Your car has a regulator already (at least it came with one and should still be there), mounted on the fuel rail.

 

The Airtex pump is commonly recommended as an after market replacement, I believe, because it will fit in the same spot as the old one, with some modifications and can handle the pressure and volume necessary for the engine. I have one on my 76 and it works fine. One downside though, based on how I understand things, is that the original pump had a pressure relief valve that relieved pressure at the pump if line pressure got over about 43 - 64 psi. I don't think the Airtex has that so it could feasibly pressurize your lines to 95 psi if the return line got clogged.

 

It would be worth measuring fuel pressure with a gauge and checking your return line and regulator if it is very high. I would be interested to know if you get a very high pressure reading since I have the same pump and have wondered what would happen if the return line got pinched or clogged.

 

There are also several other reasons for your car to run rich, too many to take a guess, many due to temperature sensors and corroded connections. You could probably learn a lot just by searching the word "rich". It's a fairly common problem.

[kelltainer]

right the whole running rich problem could be due to other things but to me this was more important to look at. I have hard hoses and other things that will have to be changed but I am saving some of these because I will be doing an engine swap sometime.

 

I will check the lines as well with the pressure gauge and yes thank you i said the wrong thing =(. I am guessing that this pump will be good for a stock turbo swap then right?

[NewZed]

right the whole running rich problem could be due to other things but to me this was more important to look at. I have hard hoses and other things that will have to be changed but I am saving some of these because I will be doing an engine swap sometime.

 

I will check the lines as well with the pressure gauge and yes thank you i said the wrong thing =(. I am guessing that this pump will be good for a stock turbo swap then right?

 

This link might help you out - http://www.xenons130.com/reference.html. There is another unzip utility called winrar out there if you don't have winzip.

 

The Engine Fuel section is worth studying. There is some unusual stuff used to make these engines work, especially if you grew up on old American cars.

[kelltainer]

ok great thanks!