which pump

[carsaval]

I need to get a new fue pump I have 560cc evo injectors, stock fuel everything except rewire, and safc. I am still running into fuel cut so next is the pump I want something thought that will flow enough for the injectors but where I dont have to upgrade my fuel pressure regulator. would a wlabro 190lph be enough?

 

[drocks22]

Yeah that walbro should be plenty for now, but if you continue to modify your car you might eventually have to switch to a 255.

 

[andymoraitis]

Fuel cut has nothing to do with insufficuent fuel supply but is caused by the MAF sensing too much airflow and cutting the fuel as a safety precaution. When you install the 560's you can either run an AFC (crap) or something like DSM Link or a chipped EPROM ECU to compensate for them. With Link and the chipped ECU, you have an option to remove fuel cut.

As far as the pump, it depends on the goals for the car. I'd buy the 255 HP Walbro (which will also require an AFPR due to stock FPR overrun) and not have to upgrade again. The 190 is still a capable pump and although it will overrun the stock FPR slightly, you can get away without needing an adjustable regulator to deal with it. If you pick up a 190 I would at least re-wire it to get max voltage under load.

It really depends on your goals and your budget.

Make sense?

Andy

 

[just2asian]

Well put Andy. Question? Do you think it is crucial to rewire the 190 or can you get away without rewiring it?

 

[bob11187]

I would recomend just going to the 255 since it leaves you more room to play with for future mods and there is little if any price difference.

 

[just2asian]

Little price difference yes, but you have to remember that you would also need to buy a fpr.

 

[blkwidow]

If you want something cheap you could always get an EVO fuel pump. Flows about as much as 190 and can be had for really cheap. Im like everyone else though, I'd rather upgrade once and be done with it.

 

[carsaval]

ok thanks so my fuel cut isnt the pump then. Can i change the subject to how can tune to where fuel cut wont happen. I have a big evo III 16g, the 560scc an SAFAC II, fuel pump rewire, and a mbr. Any help on this will be awesome.

 

[andymoraitis]

As you subtract fuel with the AFC, it fools the ECU into thinking that less air is moving past the MAF which will either delay or eliminate fuel cut entirely based on the amount of airflow subtraction. The downside is that when the ECU sees less airflow, it adds timing. On a 2G, the highest airflow table occurs above 2.1 g/rev which means that timing will peak at 16 degrees. Based on your correction factors, you'll always be in a tail chase between trying to stave off knock and running lean enough. Since you'll be taking airflow away, you'll see more and it's going to be a balancing act between boost, timing and an efficient air/fuel ratio.

Keep in mind that the base correction values for your injectors will only get it to a factory air/fuel ratio of 9.5:1 (piggy rich). If you take more fuel away to get to say 11:1, you'll add even more timing as a result of the airflow subtraction. See what I mean about chasing your tail? Cosider as well that EVO 560's flow closer to 600 so they'll need more airflow subtraction to hit base A/F.

The 190 should be fine. You don't have to re-wire it as I hadn't done mine but I do recommend it to achieve solid flow as demands become higher on the pump. You may be fuel cutting now, but fuel isn't the reason. I would still upgrade the pump irrespective of whether you added larger injectors or not. It's a must as far as I'm concerned. You also need to invest in a logger to monitor timing and look for dips that would indicate that the motor is knocking.

Cheers,

A.