Fuel system setup questions, ca18 running rich.

[plv]

Right now Im getting like 10mpg and the car is running kinda rich (but it feels like its running lean at high rpms though, but im not sure). my fuel setup right now is:

-t28/t3 hybrid turbo-z32 maf-walbro 255-untuned safc I-stock injectors (my boost setting is way too low for the turbo i have so it lags like hell, cant turn it up because ill run lean with this size injectors)

Im planning on getting dsm blue top 450cc injectors soon (are these hard to install btw?) My friend told me that i need a FPR too. SO my question is should I get the FPR before I get the safc tuned? Do I really need it? Am I missing anything else? I want to have everything ready before I spend money getting it tuned at the dyno.

[Chris859]

Ok... z32 maf, stock injectors,255lph pump and larger turbo - if I was reading it correctly, you are running this set-up un-tuned?? If so that is your problem! You can't just change the maf and not tune it for the new maf! I am assuming this is a ca18det - stock fuel system can handle 10-12psi of boost (assuming it is running right). On the running rich issue - I bet you are, it is a commonly known fact that using the 255lph pump over-runs the stock ca18 fpr and causes you to run rich. And if you are running lean on top due to being untuned on a weird setup - I would suggest you stop driving it untill you get it tuned so you don't kill your engine.

[plv]

^thanks for the reply. i never drive it at all because its been down months now because im changing the rear main seal and getting some other stuff sorted out. ill be done with that very soon though. and when i did drive it i stayed in low rpms most of the time. is it even possible to "feel" that ur engine is running lean? like i dont know what it is, it just doesnt feels right after like 6000rpms.

how hard is it to install a fpr? what about injectors? like is gas going to spray everywhere when i disconnect the fuel rail? lol im a noob.

[Indecisive]

^thanks for the reply. i never drive it at all because its been down months now because im changing the rear main seal and getting some other stuff sorted out. ill be done with that very soon though. and when i did drive it i stayed in low rpms most of the time. is it even possible to "feel" that ur engine is running lean? like i dont know what it is, it just doesnt feels right after like 6000rpms.

how hard is it to install a fpr? what about injectors? like is gas going to spray everywhere when i disconnect the fuel rail? lol im a noob.

it'll only spray out everywhere if you don't release fuel pressure first. Read the thread on how to setup your FPR to find out how to release the pressure.

[boost_boy]

^thanks for the reply. i never drive it at all because its been down months now because im changing the rear main seal and getting some other stuff sorted out. ill be done with that very soon though. and when i did drive it i stayed in low rpms most of the time. is it even possible to "feel" that ur engine is running lean? like i dont know what it is, it just doesnt feels right after like 6000rpms.

how hard is it to install a fpr? what about injectors? like is gas going to spray everywhere when i disconnect the fuel rail? lol im a noob.

That's good you understand what the car feels like because if it doesn't feel right, you know not to push it to that point until you find out the problem. THe guys are right about your fpr in the fact that it needs to be changed. I recommend the 450cc injectors if you can't afford 550cc units, but you will need more injection than those 370s. As for the SAFC, it will need to be tuned, but before you do as such, make sure that all the parts that are needed to sort out your immediate fueling issues are in place and do not try to rev or drive the vehicle hard or you'll be asking for trouble. Good luck!!!!!!!!!!

Dee

[plv]

^thanks a lot all of u

i took a good look at it a few minutes ago, the fuel rail and injectors are between the intake plenun and the engine block, but there is all kind of hoses and other **** in the way. when i change the injectors and the fpr do i just unplug everything so that i can get to it? anything i have to be careful with? and the stock fpr is the thing at the very end of the fuel rail correct?

[plv]

nevermind, i just checked the fsm

about the dsm 450ccs though, the injectors themselves is all i need? or do i need a dsm resistor box?

[Chris859]

You don't need the dsm resistor box, as the ca18 already uses low impedance injectors (aka, already has a resistor box). I have heard that you will need to use the nissan injector o-rings on the dsm injectors for them to fit properly, as the dsm injectors are a slightly larger diameter on the fuel rail side.

[rico05]

And you will need to machine the fuel rail to accept the larger injector boss of the DSMs. I will have pics once mine get here to show the difference.

[datsunboy]

I didnt have to machine my injector boss'es to fit DSM 450cc.they were just a really tight fit.

[rico05]

See, I am going off of what Chris (c-rad) said. I am interested to see if you really have to as well, but since enough of of the folks I have heard using DSM 450s have had to do this, I thought I would throw it out there. I will have to wait and see for myself...

[boost_boy]

See, I am going off of what Chris (c-rad) said. I am interested to see if you really have to as well, but since enough of of the folks I have heard using DSM 450s have had to do this, I thought I would throw it out there. I will have to wait and see for myself...

YOu really do not need to machine the CA18's fuel rail, but if you're going to use the DSM injectors, it's best to at least use the exact/same seal size that comes on the CA's 370s. I've never had any of my own or anyone else's rails machined and I've used countless size injectors ranging from 550cc to 1000cc. It's all about seal choice.............That's my view on this injector crap.

Dee