Injector upgrade thoughts.

[Billnick]

Originally Posted by ace

So were the ones you took out the single hole design? From what I've read (in this thread) are inefficient compared to the multi-hole VT commodore ones.

The ones that mine appears to have are already a multi-hole design so just wondering if it's going to give better atomisation etc.

Maybe in the 98 they're already as good as the can get so I won't get any gain (except if mine are clogged and could use a clean anyway. Apparently the engine is only 120k old anyway.

The ones I took out were single hole. See if you can get a number off of yours and check the numbers on the first post, and open up the links for more info.

[junglejuice]

Originally Posted by rainman

yep.
does it run alright?
I would expect a computer that is programed to fuel assuming a constant 49 psi would no go so grate if it was actually getting variable fuel pressure with a max pressure of 39psi. Stock injectors will not be atomising properly.
I would put a fuel pressure gauge on it and see what it is doing.

hesco make a fule pump assembly & FPR that will provide 49 psi constant, that will drop into a obd1 fuel tank. I'm assuming that the aux fuel tank takes a obd1 pump and the original obd2 pump would not fit.

Nah it runs like crap. I guess I could always fit the OBD2 internal FPR into mine, that would give me the higher rail pressure but would the OBD1 computer be able to handle a constant pressure as opposed to the variable that I have now?

That is why I was hoping this external FPR was a higher pressure, I couldn't find the pressure of it in my google searches....

[rainman]

Originally Posted by junglejuice

Rein it is definitely an OBD2, it is a 96 with an OBD2 PCM and no integral FPR in the fuel rail

Nah it runs like crap. I guess I could always fit the OBD2 internal FPR into mine, that would give me the higher rail pressure but would the OBD1 computer be able to handle a constant pressure as opposed to the variable that I have now?

Mate I'm confused, is the PCM in the '96 OBD1 or obd2.
either way I would put a gauge on the fuel rail so you can see what is going on befor I started swapping parts about.

[rainman]

Originally Posted by junglejuice

Rein it is definitely an OBD2, it is a 96 with an OBD2 PCM and no integral FPR in the fuel rail

Nah it runs like crap. I guess I could always fit the OBD2 internal FPR into mine, that would give me the higher rail pressure but would the OBD1 computer be able to handle a constant pressure as opposed to the variable that I have now?

Mate I'm confused, is the PCM in the '96 OBD1 or obd2.
either way I would put a gauge on the fuel rail so you can see what is going on befor I started swapping parts about.

[junglejuice]

Originally Posted by rainman

Mate I'm confused, is the PCM in the '96 OBD1 or obd2.
either way I would put a gauge on the fuel rail so you can see what is going on befor I started swapping parts about.

Ok, the OBD2 car I am referring to is one I have bought for parts, it is the one with the dual fuel and the Bosch external vacuum operated FPR.

Mine is OBD1 and am looking for ways to improve it which is why I was asking about how the extra fuel pressure would go with the OBD1 computer, I have an internal OBD2 fuel pump with its original FPR that I could use if the OBD1 PCM can cope with the constant 49psi instead of the variable pressure that it is currently using.

Does that make more sense????

JJ

[rainman]

makes sense now.
I would be amazed if a obd1 computer ran anything other than crap, if at all, with 49psi constant on the fuel rail. I would expect it to be way to rich.
if you want to play with fuel pressures get a variable FPR, links in the first post.

[Siggers]

I think whilst running in closed loop would run richer due to more fuel on the fixed duty cycle, but once out of closed loop it should adjust and lessen the amount of fuel being added to the mix?