Drove NJFC3S TII today !!
Best of both worlds
Joined: Feb 2001
Posts: 1,423
Likes: 0
From: NJ
lets say you have a stock 89-91 T2...but you buy an FCD to put on it to be safe...(maybe for a very cold night) besides it being a $100 waste on a stock car, are you also starving the fuel system?
damn, my posts are just getting dumber and dumber...
damn, my posts are just getting dumber and dumber...
Senior Member
Joined: Feb 2001
Posts: 724
Likes: 0
From: Montgomery, Al.
Originally posted by Felix Wankel
I'm about to put a FMIC, some 720s, and a TO4B hybrid (just cause my turbo is shot) on my car. I'm not even gonna put a SAFC on it. If it blows up **** it, I want a half bridge anyway. I give you permission to point and laugh when my 150k+ mile motor finally pops.
I'm about to put a FMIC, some 720s, and a TO4B hybrid (just cause my turbo is shot) on my car. I'm not even gonna put a SAFC on it. If it blows up **** it, I want a half bridge anyway. I give you permission to point and laugh when my 150k+ mile motor finally pops.
I'll make sure to have the tow line with me so I can haul your broke *** home.
Lives on the Forum
Joined: Feb 2001
Posts: 26,664
Likes: 22
From: n
Originally posted by Six Rotors
2.Mazda believe that the pressure sensor signal adjusts the fuel amount injected,according to their training manuals specifically the pressure sensor(or boost sensor) increases the amount of fuel over the base fuel map,and the atmospheric pressure sensor reduces it.I have never personally scoped the signals,but my money is on Mazda.
2.Mazda believe that the pressure sensor signal adjusts the fuel amount injected,according to their training manuals specifically the pressure sensor(or boost sensor) increases the amount of fuel over the base fuel map,and the atmospheric pressure sensor reduces it.I have never personally scoped the signals,but my money is on Mazda.
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.
This (*^#@$ is finally sinking in!  I've had too many arguments on FCD's and blown motors at this point.  I've seen the results, and it clearly shows that the boost sensor has nothing to do with fuel delivery - something the FCD nay-sayers have been hawking on for a long time.  It's the low voltage to the fuel pump that usually kills the motors, and it really has nothing to do with the FCD (sure, you can argue low fuel pump capacity and an advanced ignition is deadly, but you're overlooking the fact that the fuel pump is still the primary culprit).  Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...
-Ted
Thread Starter
Joined: Feb 2001
Posts: 7,848
Likes: 0
From: NJ
Originally posted by RETed
I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.
This (*^#@$ is finally sinking in!  I've had too many arguments on FCD's and blown motors at this point.  I've seen the results, and it clearly shows that the boost sensor has nothing to do with fuel delivery - something the FCD nay-sayers have been hawking on for a long time.  It's the low voltage to the fuel pump that usually kills the motors, and it really has nothing to do with the FCD (sure, you can argue low fuel pump capacity and an advanced ignition is deadly, but you're overlooking the fact that the fuel pump is still the primary culprit).  Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...
-Ted
I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.
This (*^#@$ is finally sinking in!  I've had too many arguments on FCD's and blown motors at this point.  I've seen the results, and it clearly shows that the boost sensor has nothing to do with fuel delivery - something the FCD nay-sayers have been hawking on for a long time.  It's the low voltage to the fuel pump that usually kills the motors, and it really has nothing to do with the FCD (sure, you can argue low fuel pump capacity and an advanced ignition is deadly, but you're overlooking the fact that the fuel pump is still the primary culprit).  Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...
-Ted
Best of both worlds
Joined: Feb 2001
Posts: 1,423
Likes: 0
From: NJ
just one simple question...
you have a stock T2
you put an FCD on
1) Does this FCD now mess with the rich/lean maps under 8psi?
2) or does it just take over when the car gets to 8psi (and plays no part under that reading) ...only takes over at 8psi (or whatever they advertise it for)
you have a stock T2
you put an FCD on
1) Does this FCD now mess with the rich/lean maps under 8psi?
2) or does it just take over when the car gets to 8psi (and plays no part under that reading) ...only takes over at 8psi (or whatever they advertise it for)
Senior Member
Joined: Feb 2001
Posts: 724
Likes: 0
From: Montgomery, Al.
Originally posted by RETed
I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.
This (*^#@$ is finally sinking in!  I've had too many arguments on FCD's and blown motors at this point.  I've seen the results, and it clearly shows that the boost sensor has nothing to do with fuel delivery - something the FCD nay-sayers have been hawking on for a long time.  It's the low voltage to the fuel pump that usually kills the motors, and it really has nothing to do with the FCD (sure, you can argue low fuel pump capacity and an advanced ignition is deadly, but you're overlooking the fact that the fuel pump is still the primary culprit).  Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...
-Ted
I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.
This (*^#@$ is finally sinking in!  I've had too many arguments on FCD's and blown motors at this point.  I've seen the results, and it clearly shows that the boost sensor has nothing to do with fuel delivery - something the FCD nay-sayers have been hawking on for a long time.  It's the low voltage to the fuel pump that usually kills the motors, and it really has nothing to do with the FCD (sure, you can argue low fuel pump capacity and an advanced ignition is deadly, but you're overlooking the fact that the fuel pump is still the primary culprit).  Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...
-Ted
Full Member
Joined: Apr 2001
Posts: 107
Likes: 0
From: 973 Area, Nj USA
Hey guyz.. All these posts about fuel cuts and blah blahs are very interesting but I have to tell you, my car's almost completely stock except for the exhaust,FCD,K&N intake,NGK platinum plugs and 10mm Magnecor wires.. I guess my point is, would a Walbro fuel pump and the above mods enough for a daily driver? I don't bring my car to the track, 'coz dunno how to drag race.. 
And besides your occasional street racing every now and then, my car's just sitting in my driveway.. In other words, I wanna keep my car running as long as I can or until I can save up some dinero for another car.. Possibly the upcoming Mitsu Evo..
And besides your occasional street racing every now and then, my car's just sitting in my driveway.. In other words, I wanna keep my car running as long as I can or until I can save up some dinero for another car.. Possibly the upcoming Mitsu Evo..
Full Member
Joined: Feb 2002
Posts: 125
Likes: 0
From: Cold
Originally posted by Mykl
The FD's computer can't even compensate for fuel and timing with a straight through turbo back exhaust, so it's not surprising that the FC has the same problem.
The FD's computer can't even compensate for fuel and timing with a straight through turbo back exhaust, so it's not surprising that the FC has the same problem.
As RETed said the pressure sensor has nothing to do with fuel delivery. Nor does it ignore timing with an FCD.
I've seen cars running FCD from 330-400rwhp. This isn't even worth arguing
Senior Member
Joined: Feb 2001
Posts: 724
Likes: 0
From: Montgomery, Al.
Originally posted by 2DoritosOnAStick
FD = speed density, FC = MAF... oops there goes your arguement.
As RETed said the pressure sensor has nothing to do with fuel delivery. Nor does it ignore timing with an FCD.
I've seen cars running FCD from 330-400rwhp. This isn't even worth arguing
FD = speed density, FC = MAF... oops there goes your arguement.
As RETed said the pressure sensor has nothing to do with fuel delivery. Nor does it ignore timing with an FCD.
I've seen cars running FCD from 330-400rwhp. This isn't even worth arguing
Senior Member
Joined: Mar 2001
Posts: 429
Likes: 0
From: Vancouver
Originally posted by RETed
I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.
-Ted
I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.
-Ted
Henrik
87TII
Full Member
Joined: Feb 2002
Posts: 125
Likes: 0
From: Cold
Originally posted by Mykl
I'm not even going to try to have this conversation with you. The condescending tone pisses me off and I'll things I shouldn't. Be more polite when you make a point. I enjoy finding out when I'm wrong, and learning from it, but not in a way that's insulting to myself.
I'm not even going to try to have this conversation with you. The condescending tone pisses me off and I'll things I shouldn't. Be more polite when you make a point. I enjoy finding out when I'm wrong, and learning from it, but not in a way that's insulting to myself.
Lives on the Forum
Joined: Feb 2001
Posts: 26,664
Likes: 22
From: n
Originally posted by Henrik
Hey Ted, I'm curious as to how you performed the test. To my knowledge, the AFM input is used during operation below where the secondaries come on. Above that the ECU is open loop and goes from fixed maps which must have a MAP sensor input. If this is correct, then diddling the boost gauge at idle won't make a difference whereas diddling it above 4k would.
Hey Ted, I'm curious as to how you performed the test. To my knowledge, the AFM input is used during operation below where the secondaries come on. Above that the ECU is open loop and goes from fixed maps which must have a MAP sensor input. If this is correct, then diddling the boost gauge at idle won't make a difference whereas diddling it above 4k would.
Tenma O-scope, 2 channel - one primary and one secondary fuel injector channel was monitored
CAS spun manually off a Bridgeport vertical manual mill (if you can believe that) to 2kRPM - CAS runs 1/2 speed, so that's 4kRPM the motor "thinks" it's running at
AFM manually propped open - to simulate at least some air is going through
MAP sensor "fooled" with a MityVac hand pump - MityVac has an integral vacuum/pressure gauge built into it
MityVac pumped from vacuum to + pressure without any noticable trace of change of pulsewidth from the fuel injector channels.
-Ted
Best of both worlds
Joined: Feb 2001
Posts: 1,423
Likes: 0
From: NJ
here is a link i found explaining some FCD stuff although i'm not sure this is right either! LOL
http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm
http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm
I wish I had a posse...
Joined: Feb 2001
Posts: 896
Likes: 0
From: Cincinnati, Ohio-Boycott Central
Originally posted by RETed
Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...
Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...
I think I AM going to start a poll!
Full Member
Joined: Jan 2002
Posts: 219
Likes: 0
From: NB, Canada
fuel pump and rewire
Ted - you da man. Thats so far above what I understand it's scary but I'm glad you are around... and the rest of you techs for that matter.
I have a fuel pump question. With an aftermarket, walbro, racing beat, (I heard 90's ford ranger pumps work well too), should the rewire mod for the stock pump be done on an aftermarket one as well or does the xtra flow make the voltage changes a non-issue?
I have a fuel pump question. With an aftermarket, walbro, racing beat, (I heard 90's ford ranger pumps work well too), should the rewire mod for the stock pump be done on an aftermarket one as well or does the xtra flow make the voltage changes a non-issue?
I am not surprised you did not see a fuel increase under those test conditions for the following reasons:
1.the pressure sensor is only used for fuel increase below 3600 rpm,above that a high speed correction is used.
2.the high speed fuel increase also uses TPS position as an input.
1.the pressure sensor is only used for fuel increase below 3600 rpm,above that a high speed correction is used.
2.the high speed fuel increase also uses TPS position as an input.
Haven't we ALL heard this
Joined: Mar 2001
Posts: 3,948
Likes: 1
From: Indiana
I don't think a FCD leans out the fuel/air mixture. The car leans its self out by design.
As the boost goes past the factory cut off it continues to dump more and more fuel. Until the injector duty cycle approaches 100%. At or before that point there is no more fuel to give. If you go past that point you will run lean.
That is why people recomend upgrading the fuel pump. That simply insures there is all of the fuel there waiting to go into the engine that the injectors will allow or can flow. So it helps make your injectors do their job.
Install bigger injectors? Even better. It allows you to give the engine more fuel and boost even higher.
This is how it seems to work. If I wrong somebody correct me so I stop giving wrong info.
James
As the boost goes past the factory cut off it continues to dump more and more fuel. Until the injector duty cycle approaches 100%. At or before that point there is no more fuel to give. If you go past that point you will run lean.
That is why people recomend upgrading the fuel pump. That simply insures there is all of the fuel there waiting to go into the engine that the injectors will allow or can flow. So it helps make your injectors do their job.
Install bigger injectors? Even better. It allows you to give the engine more fuel and boost even higher.
This is how it seems to work. If I wrong somebody correct me so I stop giving wrong info.
James
Senior Member
Joined: Jul 2001
Posts: 544
Likes: 0
From: Queens, NY-----Rockland, NY(School)
hey i have a 3 inch exhaust to the back...how bad is this as far as leaning out?
since i put it on, im scared to bring it up close or past redline cause i dont wanna break anything.
im still waiting for my air/fuel guage to get installed. but even after i get that in, it probably wont be acurate cause of my stock o2 sensor.
Mike
87 turbo2 (90 motor)
since i put it on, im scared to bring it up close or past redline cause i dont wanna break anything.
im still waiting for my air/fuel guage to get installed. but even after i get that in, it probably wont be acurate cause of my stock o2 sensor.
Mike
87 turbo2 (90 motor)
