gorockrx

OK,
I just have to know if this is right! I saw a "how-to" on the FC3s.org site for an HKS FCON install. Here is what part of that says:


Go to the area that the stock boost sendor is (passenger side strut tower) and find a place to mount the new F-CON boost sensor. Once you have it mounted, you will be tapping it's line into the boost pressure line that goes to the stock boost sensor. Make sure that the sensor is facing upward, and that the pill in the boost line is still before both boost sensors.



What????? Is there a "pill in the boost sensor vacumn line on an FC? I didn't think there were any boost pills on my 87 TII. Somone please confirm this or say it isn't true please!!!!!!!!

rx7_turbo2

Yup there IS a pill in that line. I know I had to take it out and put it back in when I swapped the line for a silicone one.

T2monster

I ordered this part today from Mazda, i was wondering if this indeed could be causing my "hesitation" when the boost comes on. My twin scroll setup and gates are removed and my boost comes on hella fast, i thought that was possibly why i was seeing hesitation, b/c the cpu was freakin out from the reading. Also, the FCD i have on the car is borrowed, and came off of an '89, will that hurt anything. I know they are listed as 2 part numbers on racing beat for 86-88 and 89-91, just wondering. If it isn't right and isn't working correctly that could explain alot of the hesitation, since the hesitation is accompanied by a tremendous lean condition for a/b .5 second, then normal open loop rich readings.


'87 TII
"Hybrid Theory"

emissions removed
twin scroll removal
FCD, autometer air/fuel guage
twin electric fans
Accel, MSD ignition
4 slightly mod Venom inj.
rx7.com 50mm y-back
gutted cats
a/c, p/s removed
'vert wheels
j-spec wing
manual boost controller
soon to be TID mod

gorockrx

Looks like I better dig thru my trash and find it. I may have already thrown it out.........arrgghhh. I am seeing the hesitation and a lean out due to no actuator and a ported turbo. I like the way the turbo spools smoother.........but got to fix that lean out.

By the way, I think the voltages are different on the 87-88 TII's than the 89-91's, so you might want to put a meter on that FCD and and see what it is doing with the stock sensor. You may be running lean thru the entire range due to different voltage (or richer).

I am going to remove my Racing Beat FCD and install my Dawes Devices fuel cut out riser that should work better. It already has the correct "pill" on it so I don't have to use the stock one. Here is the link:

http://www.dawesdevices.com/COinstructions.html

I will see how this one works since I already have it. It is supposed to keep the stock MAP sensor values all the way up to fuel cutoff. This way the computer gives the correct amount of fuel just like stock, except you can raise the cutout point to whatever boost level you want Make sure you have enough fuel for your boost level, cause once you pass the old fuel cutoff point the computer is in open loop and will not give any more fuel.

Felix Wankel

Mine had no pill when I got it. I never replaced it. I have a ported wastegeate and no twin scroll setup (among other things), and my car doesn't hesitate.

gorockrx

I should have done 1 mod at a time dangit!!!! Oh well, I will fix it eventually. Just hope my motor isn't toast already. It is idleing like crap right now, but has a ton of power. I am going to check a couple of things today. Thanks for the replies!

Felix Wankel

You still need a hood, or did you get one already?

gorockrx

YES! I still NEED a hood! I bought one and the guy never sent it. I am still trying to get some parts out of him to make up for it.

I have everything I need except for the hood, so if you have one let me know. Where in AL are you? I have family in Huntsville, Pensacola, Pascagola, and I am just south of Jackson MS.

my e-mail is gmowen@ayrix.net

TonyTurboII

Whats the part number on that thing? The parts idiot at my local dealer couldnt find it.

Felix Wankel

I was the pizza dude with the blue FB. I live in Hueytown now, about another 45 minutes away from that TII that we looked at. I'll sell you mine cheap since it has a small ding in it and a cracked scoop. Its still much straighter than the one on your car. The car with the hood is only about 20 minutes from the car lot we met at, if you remember that. If you wanted, you could drive your car out and swap the hoods. I'll take care of the old one for you.

gorockrx

Yea, I remember ya.....
Sounds good about the hood. Do you have a picture of it? What color is it now? I still have the same car that I had back then

I've done a lot to it though......as you can see from my sig. Gotta get a few things fixed still, but I am not driving it everyday right now until I get it running right.

I don't post very often, except for this last week or so, but yea, I am interested in the hood. E-mail me at my home address asap:

gmowen@ayrix.net

We can talk numbers and pictures ect.......Thanks!

Six Rotors

iTrader: (17)

For the nth time 8931-13-986

gorockrx

Hey sixrotors,
Thanx for the "pill" part number

NZConvertible

I'm not sure exactly how the RB FCD works, but some FCDs reduce the output signal by a set percentage across the board, meaning there's always an error in the fuelling (bad). Others (like the TeamFC3S DIY FCD) follow the factory sensor's voltage exactly and then clamp it just below the fuel cut voltage (good). If the RB FCD works like this, you'll see no benefit in changing to the Dawes, as it's doing exactly the same thing (just pnuematically instead of electronically).
The boost point where fuel cut happens (8.6psi) is part of the ECU's firmware and can't be changed without reprogramming. You need to adjust the unit so it bleeds pressure just below this point.
Personally I think the electronic method would be a bit more reliable. At least you don't have to clean your FCD every week!

gorockrx

I got one of those Dawes Devices mainly for testing. I like the air/fuel meter they have made as well.

I already had the RB FCD unit and it worked fine on my last 2 Turbo II's that I insalled it on. This is my 7th RX7 and I have scrapped together what I could to make this car nice. It was almost perfect until I hit a deer last year

When I got married I sold almost all my RX7's and parts, so this is all I have left.

I know about the error induced by the FCD's, but I'm not sure if mine is working right or not, so that is the reason for the other one. I will most likely be going to stand-alone anyway (when I get some more $$ ), so this is temporary.

I like the idea of the boost sensor seeing a stock signal all the way until cutout. This way I know for sure it is not getting an error. I just didn't realize that the stock vacumn line had a "pill" in it.

Thanks for all the good replies!

gorockrx

By the way, I believe the error from the boost sensor will show up as a timing error. It is for boost retard I think. I have heard that before on the forum, and I believe that most OEM cars are set up that way for those years. Correct me if I am wrong please

Anyway, the AFM and TPS are what I have to "tune" to get the lean out fixed. I just did a LOT of work and some mods to my car all at the same time, and I have not got the "bugs" out yet.

I will get it smoothed out. My main problem was that my wastegate arm came off of the door arm, so I was getting max boost with no wastegate bleed off. That gives a GREAT spool up, but leans it out a bit when stepped on fast and of course I really didn't want 15psi with my setup. I don't have the fuel for that.

The AFM is really slow at catching up with the TPS.
At least that is my best educated guess. It was even worse before I removed the "Dual-Scroll" door and actuator.

I can't wait to get a stand-alone and get rid of the AFM!