FCD voltage!!!

[porzeczka00]

What voltage do I set the FCD to?
I've searched DSMtuners, DSMtalk, 2gNT. And I did not find an answer to my question.
My question is this what should be the voltage set at on the FCD? I have a 1999 RS. (12:1 FMU, 255 Walbro pump not that it matters) I'm trying to run 5psi. I tried fine tunning the FCD and I was at a point where it wouldn't idle at all. Then I got it to idle and when I would press the gas it would have a REV limiter at 4,000rpm. Now my voltage is at -4.18v and this is what happens. It rev limits at 6,300rpm. I guess it's just not allowing boost, every time my Boost Gauge hits 0psi it cuts off. So the point is what should the voltage reading on the FCD be, please give me examples of what you guys have it set at... (Just as an aside I'm gonna post pictures when I'm done I put on a TD04 off my buddys 2002WRX i don't think it's been done before... hehe! I'm psyched!) Thanks for your help!

 

[luvmygst]

do you have a missing link installed?

 

[Locke]

do you have a missing link installed?

Missing Link is hit-or-miss. An FCD is a solid-state alternative that serves the same purpose.

Try setting it around 4.6V and adjust from there. It seems everybody else's are between 4.5V and 4.7V.

 

[porzeczka00]

Nope no missing link it mite be a good idea since the MAP wasnt made for pressure... thanx for the feedback... i'm gonna try like u said start at 4.5v... the instructions i got with mine said below 4.7v but that also means 1.0v but a range is a good idea to try thanx a lot! i'll post again tell you if it worked.

 

[VelocitàPaola]

Do you have one of my FCDs? I always set them to 4.58V... I've found that's a good value to start with.

 

[mirandaeclipse]

i set my fcd at 3.20, and the fuel cut appears at 4psi at 5500 rpms.
paul i took the 12v source from the battery it´s that ok?

 

[xXaTaXx]

i set my fcd at 3.20, and the fuel cut appears at 4psi at 5500 rpms.
paul i took the 12v source from the battery it´s that ok?

I know this was directed at paul, but I just wanted to throw in my two cents.
Recently, I purchased one of paul's FCD's. For the first couple of days, I had the wires solderless clamped to make sure I didn't screw up. During this timeframe, I had the +12V source directly off the positive post. It dosen't seem to make a difference. As for a more permanant lead to use for the FCD, there is a snake (wire cover) that comes over the passenger side of the valve cover. Inside that, you will find a black wire with a red stripe. Snip some of the plastic off that lead and solder on your wire for the FCD +12V source.

As for tuning the FCD, I'm not turbo yet so I can't explain what happens in boost. But, I have throughly explored the changes that the FCD makes to my engine's performance. I believe your FCD set WAY to low. When your changing the resistance (screw type thing), and your engine starts to bog or dies. Turn that screw all the way in the opposite direction and start tuning from there. Going too low on the MAP voltage causes the fuel cut, I believe the ECU is tricked into believing that there isn't enough air coming in and leans everything out.

As for when I am turbo, or if you are already turbo. I have and you should make a 'harness' for the FCD. What I mean by that is get some simple connectors from radioshack (I think I used serial connectors for pc's ;D) and make it so you have something like this:

FCD->Male Serial == Female Serial <-- MAP

because then you can make an extension and actually keep the FCD in your cabin and tune while driving.

Eh, just thought I'd share my thoughts on installing this FCD ;D. You can also make your car sound like a WRX w/ the 500RPM idle ;X haha.

Thanks Paul, Hopefully I get to take it testing w/ boost soon.
Chris

 

[4UH8ERS]

I guess it's just not allowing boost, every time my Boost Gauge hits 0psi it cuts off.

Do you get fuel cut at 0 psi? or do you mean that you dont get fuel cut, but its still not building boost?

Either way you need to raise the voltage on that fcd.

 

[xXaTaXx]

Do you get fuel cut at 0 psi? or do you mean that you dont get fuel cut, but its still not building boost?

Either way you need to raise the voltage on that fcd.

Maybe he dosent have the OUT line to the ECU right.
Meh, Just a thought ;D

Chris

 

[VelocitàPaola]

i set my fcd at 3.20, and the fuel cut appears at 4psi at 5500 rpms.
paul i took the 12v source from the battery it´s that ok?

3.20V is too low. Like I said, start at 4.6V, then slowly turn it downward in increments of 0.05V until fuel cut is gone.

12V straight from the battery will put a continuous drain on the battery; although the current draw is miniscule. Look for a +12V that's switched every time you start the car.

 

[VelocitàPaola]

Hey Chris, wanna work as tech support for SymTech?

 

[xXaTaXx]

Hey Chris, wanna work as tech support for SymTech?

Actually, yeah.
Its what I'm good at ;P

Chris.

 

[totaleclipse_05]

Make sure to remove the MAP sensor from the intake manifold and blow into it with the key in the ON position and read the voltage with a multimeter. Blowing into the MAP sensor should register at least 1 psi of boost so tune the FCD's voltage to somewhere around 4.6v and start from there. Like Paul said too, find a 12v switchable source so the battery won't get drained while the car is off. I personally tee'ed off the cig lighter 12v power and ran a wire to the engine bay where my FCD is located.

 

[porzeczka00]

MORE QUESTIONS !!! OK i had an arthroscopic done on my knee so i wasen't able to tune the FCD. But i did get into the car today and this is what happened at 4.59v while standing still i was able to get the boost up to 7psi a smooth tranistion from 800rpm - 6,500rpm. But when i took it on the road here is what happened (in 1st gear): The car felt like it was starting to build pressure, meaning i was getting the feeling like it was, I looked at the gauage and it said 0psi and then all of the sudden it cut me off at 4,500rpm. So i pulled over and turned it down .05, it got worse then another .05 and it got worse so on and so forth. So i figured lets go the other way now, and so i turned it back to 4.59 and i sitll got about a quater turn left on the fine adjustment screw but the voltage does not go past 4.59v. When I first put it in it was at 4.74v, I can't figure out why i can't go past the 4.59v. I'm tapped into the cigarett lighter like someone mentioned. Ok let me just add I don't have an exhaust on it yet, what so ever it's just running into the engine bay, ok before anyone says anything, yes i know that's bad and I will be putting an exhaust on it but I gotta wait for custom piping. On top of that when I did boost to 7psi. and when I drove around in second gear I saw A LOT of WHITE SMOKE. Does this mean I'm running LEAN? My fuel set up rite now is like i mentioned (255 Walbro pump, 12:1 OBX FMU, stock FPR) the only problem I could think of is that my injectors mite need to be replaced being they're 8yrs old. Ok let me just ADD this to everything above being I don't have the exhaust i'm missing the 02 sensors. also a question I got a 02 sensor simulator that can only be used to replace the 2nd one after the exhaust rite?

 

[porzeczka00]

OK I JUST WANT TO SAY THANKS TO EVERYONE WHO HAS AND WILL REPLY TO THIS THREAD I REALLY APPRECIATE ALL OF YOU TAKING TIME OUT OF YOUR LIVES TO HELP ME! THANKS A LOT!

 

[VelocitàPaola]

MORE QUESTIONS !!! OK i had an arthroscopic done on my knee so i wasen't able to tune the FCD. But i did get into the car today and this is what happened at 4.59v while standing still i was able to get the boost up to 7psi a smooth tranistion from 800rpm - 6,500rpm. But when i took it on the road here is what happened (in 1st gear): The car felt like it was starting to build pressure, meaning i was getting the feeling like it was, I looked at the gauage and it said 0psi and then all of the sudden it cut me off at 4,500rpm. So i pulled over and turned it down .05, it got worse then another .05 and it got worse so on and so forth. So i figured lets go the other way now, and so i turned it back to 4.59 and i sitll got about a quater turn left on the fine adjustment screw but the voltage does not go past 4.59v. When I first put it in it was at 4.74v, I can't figure out why i can't go past the 4.59v. I'm tapped into the cigarett lighter like someone mentioned. Ok let me just add I don't have an exhaust on it yet, what so ever it's just running into the engine bay, ok before anyone says anything, yes i know that's bad and I will be putting an exhaust on it but I gotta wait for custom piping. On top of that when I did boost to 7psi. and when I drove around in second gear I saw A LOT of WHITE SMOKE. Does this mean I'm running LEAN? My fuel set up rite now is like i mentioned (255 Walbro pump, 12:1 OBX FMU, stock FPR) the only problem I could think of is that my injectors mite need to be replaced being they're 8yrs old. Ok let me just ADD this to everything above being I don't have the exhaust i'm missing the 02 sensors. also a question I got a 02 sensor simulator that can only be used to replace the 2nd one after the exhaust rite?

Wow, I just had someone else with one of my FCDs do the exact same thing less than two weeks ago! The reason for your fuel cut in this case is the missing exhaust. You absolutely need the front O2 sensor connected to a good, solid downpipe.

It's perfectly fine to eliminate the second (downstream) O2 sensor, but the first one must be connected and functioning properly. You'll continue to get fuel cut until you have a proper exhaust installed.

Furthermore, those exhaust gases are probably destroying everything in your engine bay. I'm not even exaggerating; that's a pretty serious issue that you need to get taken care of immediately. It's one thing to have the car idle without a downpipe, but driving it around is very dangerous.

 

[porzeczka00]

I HAD A FEELING!!!! I'll probably have to go to a junk yard because b4 I went turbo my check engine was on for a bad MAFS and the O2... THANKS A LOT MAN!!!! as for drving around with no exhaust i'm just speaking for myself and not recommend it to anyone but i'm a fireman so i know a lot about flammable gasses and the conditions it would take for the CO to ignite... but thanks for the heads up!

 

[Locke]

I HAD A FEELING!!!! I'll probably have to go to a junk yard because b4 I went turbo my check engine was on for a bad MAFS and the O2... THANKS A LOT MAN!!!! as for drving around with no exhaust i'm just speaking for myself and not recommend it to anyone but i'm a fireman so i know a lot about flammable gasses and the conditions it would take for the CO to ignite... but thanks for the heads up!

We have a MAP sensor, not a MAF sensor.

Not so concerned about the exhaust igniting, (hah, afterburner) as the heat of the exhaust damaging your fans and electrical insulators. If your turbo is mounted the way we conventionally have it, and your wastegate closes, it could cause a failure in your upper radiator hose as well.

 

[porzeczka00]

Secondly, my turbo is not conventionally mounted, therefore I am not worried about anything getting damaged, the electrical insulator, fans, and especially the upper radiator hose. I took out one of the fans becuase the turbo would not fit, and no the car will not overheat. The only thing I will agree with you on is that we have a MAP not a MAF, because I did not know that. Would you be kind enough to inform me about what MAP stands for? Thank you for your feedback!

 

[VelocitàPaola]

We don't need English lessons from anyone here... regardless, we do have rules about grammar and spelling which expressly prohibit the use of "internet slang." Please use more discretion in the future.

 

[porzeczka00]

Nicely put.

 

[Locke]

Would you be kind enough to inform me about what MAP stands for?

MAP = Manifold Absolute Pressure

It is used in speed density systems of air metering (that we use) along with the IAT (Intake Air Temperature) and a tachometer signal. The MAP and IAT are used in conjunction to determine the density of the incoming air, while the tach signal and the ECU's own knowledge of the motor's displacement determine the rate at which it is consumed.

 

[xXaTaXx]

MAP = Manifold Absolute Pressure

It is used in speed density systems of air metering (that we use) along with the IAT (Intake Air Temperature) and a tachometer signal. The MAP and IAT are used in conjunction to determine the density of the incoming air, while the tach signal and the ECU's own knowledge of the motor's displacement determine the rate at which it is consumed.

Nicely put.

Chris.
I'll be turbo soon, but the DMV keeps holding me down. another $150 in non-driving/non-moving violations. ;(

 

[porzeczka00]

Ok back to this thread again... how does a MISSING LINK sound? I'm fed up with this FCD. I was adjusting it on my driveway, it was ok idle - 6500rpm. I get on the road, let go the clutch the thing stutters like hell and then it dies, so I keep adjusting and adjusting, nothing it wasn't going past 4.66v. Finally I tried to set-up my meter so I can drive and when it dies just adjust the screw .02v either way. As I was doing that I figured the only place my negative cable will reach is the lighter, and so my hand slips and there goes 12v through the fcd and the MAP sensor. All i read now is 1.40v no matter what I do. I hope it's just the FCD and not the MAP. Any ideas of what should I do next?

 

[VelocitàPaola]

Send me the FCD so I can troubleshoot it. I'll tell you quickly whether it's the FCD or something else on your car. If it's the FCD, I'll send you a replacement immediately, no questions asked. I will say this, though, I've sold so many of these I can't even count them all; but not one person has actually had a problem uness it was due to their own negligence. I'm not saying this can't be the first case where the FCD is truly faulty, I just find it highly unlikely as I personally test each unit.

The ML is a horrible idea... if you think you have reliability problems now, try finding a small cotton filter to replace every other week.