questions about fuel delivery and the like

[RM12577]

alright, ive had my CA for a while and it has been running rich since i put it in. i set the fuel pressure to what i was told to run it at but since then my fuel pressure gauge has broken due to vibration (hockey puck mounts....) need some suggestions on what to run for a fuel pressure gauge that can take some vibes and also any ideas on what i can do to get the car to stop running so rich. I have an intake and 3 inch exhaust on it. also was thinking about having it tuned, kinda a stupid question that i have no clue about, to have a car tuned do you have to have separate fuel management or can they tune the stock ecu without me having to add anything? One of these days im going to take some pics of my car and post them but ive been lazy as of recently...

[Ca_Silvia]

Most Fuel pressure gauges sit in the fuel line so i would guess that the rubber line dampens some of the vibration. If your still worried get a gauage and mount it under the hood like Rico. Check out FRsport.com they are a sponser and i use them regularily with no issues.

Tuning you are correct you can buy a pre made "chip" and have someone socket you ECU to install it and then that it. Or you can go standalone. Chip will be cheaper but will also yeild smaller gains then compared to standalone. And then there is the price of chips vs. standalones.

[ca18detgabby]

you also have the option to run a piggy back or Super air fuel contoller.

I picked one of these up cheap and going to try it



http://www.vortechsupercharger...key=5

installing sat will let others know about my results

[rico05]

Autometer manual gauge ($25 off eBay with mount), Moroso 5/16 fuel line adaptor and Summit 1' SS line and approptiate 1-8"NPT fitting. Total of about $35-$40.

As for tuning the ECU: There are lots of options. You can wire in an Apex S-AFC, AFC-Neo or V-AFC (for vtec, but works the same) or a GReddy e-Manage of some flavor. These are referred to as "piggy back" systems in that you run the factory ECU, but wire these systems in line. Basically, they intercept certian signals to the ECU and allow you to recalibrate them, essentially tricking the ECU into seeing certian conditions and allowing you to tune.

Another method is actually reprogramming the stock PROM chip. The PROM holds all the refrence maps for spark and fuel control, based on a series of algorythms that are executed by the processor. Now, you can simply replace this chip with a programmable one (an EPROM) that will be a one time tune (like I run a chip for removed speed cut and a KA24E MAF), and every time you make a change you have to physically remove the chip and reflash it. Kind of a pain, but simple to execute.

Now, you can also run a system like the Pocket Romulator or the Nistune (google each). These replace the stock chip with a separate board that allows you to on the fly tune. You can create different switchable maps (high boost, low boost, race gas, valet etc) and control auxuilary devices like fans or water injection. They still utilize the factory sensor array (ie MAF and CAS), and are limited to how far you can tune them (like for auxuilary injector control). But they are cheap and you don't rewire the engine.

The ultimate is a full programmable stand alone. Anything from a simple Megasquirt all the way up to a MoTec, Techmotive, SDS or AEM EMS. These systems allow complete control of all functions, as well as many other systems (water/meth/alc injection, extra injectors, etc) BUT they are expensive and time consuming to calibrate. Ultimatly, the stand alone is one of the single best modifications you can ever do for your car. And also one of the most difficult for a novice to execute.

[Buddyworm]

Chip will be cheaper but will also yeild smaller gains then compared to standalone.

False. The system used to tune the engine has precious little to do with its final output. All the systems (including the stock ECU) function on the same basic principles, the single largest advantage standalone systems have is the ability to run various types of sensors (MAP sensors, yadda yadda).

That is, unless, like rico stated above, you factor in crazy **** like meth injection and extra injectors. Waaaay beyond the scope of most people's plans or needs.

[jt15833]

Tunes can add alot of power if the car has bad afr's. I always thought my car ran great, only mods

CA18 stock turboFMICWalbro 190lph

Then I upgraded to a SR turbo and got a new intake w/ K&N cone. I wanted something to tune with so I bought a stock CA18 board in Australia and sent it to the nistune http://www.nistune.com/ guys. 400 AUS mods your ECU with a USB port, gives you a USB cable and single Nistune license. Check the pics on that site. It is very powerful for what it can do compared to it's cost and ease of installation. No wiring involved and you can change rev/speed limit, inj, air filter, fuel maps, timing maps. It can also log and take in a wideband airflow signal.

Anyway this is where my troubles began. I got an LM-1 for the wideband ability ($300 on ebay). To my surprise, with the SR turbo and the stock CA18 box intake my air fuels were going down to 10.7. Fuel system is stock except walbro 190lph. After the intake w/ K&N and a new fuel filter, my airfuels only go down to 11.2 at WOT.

I got it dynoed with the stock CA turbo and it made 160whp/180wtq - also hinting rich condition, before I had the LM-1 though (source r34 gtr).

The new SR turbo is running only 8 psi compared to CA ~12, and was a little slower i'd say. But when I changed the intake from stock box to the intake w/ k&n cone, the car felt much better than the CA turbo even 4 less psi. The changing of the air filter coincided with a .5 raise in air fuel ratio, which is why it felt much better than a new turbo.

The reason I'm explaining all this is because the afr's determine alot of power. It's how you make power, the leaner you go the more power but the more dangerous. So, for an untuned car expect big gains from correcting your incorrect AFR's!

LONGER STORY NOT NECESSARYI had always heard the stock FPR is fine if it's working so I'm hoping mine isn't working, because my air fuels are horrible. I installed a air fuel pressure gauge and it does indicate more pressure. When I do my headgasket I will be installing a nismo fpr (looks much easier with head off). I'm expecting a pretty good power increase with that and a working wideband and a tune to get my AFR's around 12.5, and then increasing the boost to 12psi will make a car I thought was running good, run much much better. I heard 230 whp is good for the top end of the T25G, and my same car w/ CA18 made 160whp, I wouldn't doubt getting real close to the top end number. Sorry for the long post it's hard to put numbers into words.

[rico05]

AFRs and EGTs will tell you everything you need to know 90% of the time when tuning a street engine with bolt ons (any part that is SKU'ed is a bolt on in my book, btw).

[capowered240]

Here is another way to put fuel pressure gauge in.

[The_Chosen_One]

You could a little extra cash and get a Electronic Fuel Pressure gauge. Sensor stays in the engine bay and gauges inside the cockpit. This eliminates the chance of a line bursting inside the cabin and you going boom boom.

http://prosportgauges.com/ambe....aspx

[jt15833]

i put a gauge inline but removed it after adjusting the fuel pressure. there is not a point in having it unless you need to adjust pressure or think there is a fueling issue.

[RM12577]

well the car is running real rich and is backfiring on shifts and when decelerating, i had a pretty good looking fuel pressure gauge attached permanently in the line but the whole vibration thing make it stop working, cost me 60 bucks for the gauge so i might go with the in car electronic version since it would be less likely to vibrate to pieces in there. ill look into fuel systems, i might just crank my fuel pressure down a little less to see if it will run any better..... i dont have much money for a system upgrade and wont for a while.... that and its my only vehicle for the time being and i wouldnt be able to do any work that would be more than a couple hours worth on it..... thanks for all the info though it will be useful later on when i get some more money

[dash]

does your car run rich at all times, even idle ?What color are your injectors ? Do you have the oe resistor wired in ?stock fuel pump ?

If its all stock I'd continue tracing the problem rather than any tuning attempt.... especially at todays' gas prices. You'll need a good-running baseline to work off.

[dash]

I picked one of these up cheap and going to try it

that FMU will probably make you too rich up top.Thats a common component in entry level turbo systems installed on factory normally aspirated motors, still maintaining stock injectors - which would suffer lean meltdown without the FMU... I doubt thats your situation

Is that Vortech FMU 12:1 ?Where did you find it cheap ?I'm currently looking for one to use on my corolla FX16 turbo 4AG project