[HJones1313]

Originally Posted by JLMounce

It's the achilles hill of all TBI based systems. frame mount pumps fail frequently and that command center still requires a vent line that most people try to use the factory vent with and it does not work.

It's a bit more money, but the ultimate setup is a new EFI ready tank with an in-tank pump. It's easier to install, quieter and will be more reliable.

The command center is something like $395 and is a pain to install and you still need to run a vent back to the tank as the factory line (if your car is equipped) can not handle the volume. I got my entire setup including the tank, walbro 255 lph pump, sending unit, straps, rollover vent for right at $500.00 shipped.

I tried going the cheaper method first and because the factory return line on the tank could not flow enough return fluid I go pressure creep and the car would flood and stall. Once I bit the bullet and purchased the tanks in system with their pump, the car has been stone cold reliable.

I think this is like the 5th post I've made in this entire thread basically saying the same thing, so I guess I should yell.

DON'T USE THE FRAME MOUNT OF COMMAND CENTER FUEL SYSTEM! THEY ARE **** AND DO NOT WORK! BUY A DEDICATED EFI FUEL TANK AND IN-TANK PUMP!

What he said!!!

[HJones1313]

Originally Posted by HWYSTR455

No, but you will be changing it frequently. And it could leave you stranded more than once. My suggestion would be to carry a spare.

Ask guys who have done Power Tours, see what they think. Not to mention the noise.

.

What he said too!!!

[JLMounce]

The failures in the Fuel Command Center seem to be related to both how they are installed as well as not setting up the calibration file to utilize pulse width modulation.

The result is too much incoming fuel and the pump not being powered down during cruise or off-throttle decel. That results in severely premature death of the pump.

Because fuel is shut off during decel (unless otherwise calibrated) you can't just use the car's original vapor return. That line is much too small to handle anything other than vapor, but the FCC needs to have a vent/return in situations of over-filling. This means running a new line back to the tank anyhow. Those who try and use a factory 5/16" crush bent vapor line may have issues unless their car is a gas hog or the factory pump setup didn't provide adequate fuel to begin with.

The FiTech unit comes shipped assuming you're running a traditional pump with return line. If you're running the FCC you need to calibrate it for PWM. They have a video tutorial in their tech section that gives step by step instructions on how to do that.

[1980 TA]

Completely agree with the frame mounted external pump. Tried the holley projection when it came out the frame mounted pump was the limiting factor with it. With 1/2 tank of gas or better it worked great but anything under a 1/2 tank it was super inconsistent.

I read through all 49 pages last night and one thing I am still a little unsure of with respect to the FCC. It is my understanding that it has a needle and seat to prevent it from overfilling. My factory mechanical pump has a return line for excess volume. When the FCC closes the needle and seat, the mechanical pump should bypass fuel back the tank as it does now when the floats close on the carb.

Is the overflow of the vent due to the pump getting hot from a pressure build up from the throttle body restricting flow under times of low need? I assume the new protocol requiring PWM control is designed to combat this?

Trying to wrap my head around why the FCC would experience a large volume of extra fuel when the mechanical pump should be sending the excess back to the tank?

Thanks to everyone that has taken the time to respond. I'm learning a lot.

BTW I have two like new frame mounted pumps from my foray into the projection if anyone wants them. )

[1966socalgoat]

Manual fuel pump to Robbmc electric up front with a 1/2" return line, no issues runs great. Google "fuel surge tank", many hi hp autocross and drift racers run them to ensure adequate fuel supply

[JLMounce]

Originally Posted by 1980 TA

Completely agree with the frame mounted external pump. Tried the holley projection when it came out the frame mounted pump was the limiting factor with it. With 1/2 tank of gas or better it worked great but anything under a 1/2 tank it was super inconsistent.

I read through all 49 pages last night and one thing I am still a little unsure of with respect to the FCC. It is my understanding that it has a needle and seat to prevent it from overfilling. My factory mechanical pump has a return line for excess volume. When the FCC closes the needle and seat, the mechanical pump should bypass fuel back the tank as it does now when the floats close on the carb.

Is the overflow of the vent due to the pump getting hot from a pressure build up from the throttle body restricting flow under times of low need? I assume the new protocol requiring PWM control is designed to combat this?

Trying to wrap my head around why the FCC would experience a large volume of extra fuel when the mechanical pump should be sending the excess back to the tank?

Thanks to everyone that has taken the time to respond. I'm learning a lot.

BTW I have two like new frame mounted pumps from my foray into the projection if anyone wants them. )

The factory return on the mechanical pump is a vapor return line. While some liquid fuel may pass through it, back to the tank, the line is not designed for, or adequate in size enough to transport any real quantity of liquid fuel. On a carbureted setup with a mechanical pump the majority of fuel is always heading to the carb's bowls. The advent of the return line in this system is not to return fuel to the tank, but to alleviate vapor lock symptoms by transporting fuel vapor back to the tank.

Like the fuel tank itself the command center has to cope with expansion and vacuum rates as the tank fills and expels fuel, so it needs the vent. It shouldn't over fill, but in the case it does, that vent needs to be of adequate size to allow liquid fuel to return to the tank.

While I think the above is a contributing factor, the failures are still probably because people aren't setting up the system to use PWM with the FCC.

[FrankieT/A]

I am using the Tanks Inc. tank and the Walbro GPA-6 which is rated for 400 liters per hour (way overkill) pumped through 1/2" line from tank to TB and the factory 5/16" return...no issues.

[angelo]

I think there is some confusion in this thread. JLMounce last reply I believe is in reference to the in-line fuel pump that FiTech provides, not the actual "Fuel Control Center". The FCC is designed to accept low pressure from a mechanical pump and can manage its large fuel bowl and it stops its bowl from being overfilled automatically, just like a carburetor keeps its bowl from being overfilled from the same low pressure mechanical pump.

Three scenarios:

1. Inline fuel pump that is not submerged in fuel - We can all agree that these fuel pumps are not reliable and have a bad reputation. You have to run a high pressure return line for this style fuel pump.

2.. In-take fuel pump - This is the best solution if you are capable of running new high pressure lines both to and from the tank / engine bay. You also have to run a high pressure return line for this style pump.

3. FiTech's Fuel Control Center (FCC) - This is a fuel pump submerged in fuel that is mounted in the engine bay. When used with FiTech EFI there is no need to run a high pressure line back to the fuel tank. This is a good solution if you do not want to change the fuel and vapor lines to/from the tank. Technically this can be reversed easily as well, perfect solution if you have a numbers matching car and may someday put the carb back.

The FCC vapor out does not leak fuel when you have everything setup correctly, it is only vapors that come from it. There is no high pressure return line that comes out of the FCC. Essentially the FCC accepts the same amount of lower pressure fuel that a carburetor would accept. The FCC (just like a carb) can keep its fuel bowl full and stop the flow of fuel from the low pressure fuel pump when it is not needed, that way the mechanical pump can use the return fuel line (if your car has that) or simply hold the fuel pressure (how fuel pumps work without a return line). The FCC creates high pressure from their fuel bowl (which is much bigger than a carb fuel bowl) and provides the exact amount of fuel the throttle body needs which is why when you use this setup you do not need a high pressure return line. I have been using the FCC with my FiTech throttle body since Fall of 2015 without issues.

[gassman_67]

What is the preferred location of the O2 bung on an TH400 equipped GTO?

[JLMounce]

Originally Posted by angelo

I think there is some confusion in this thread. JLMounce last reply I believe is in reference to the in-line fuel pump that FiTech provides, not the actual "Fuel Control Center". The FCC is designed to accept low pressure from a mechanical pump and can manage its large fuel bowl and it stops its bowl from being overfilled automatically, just like a carburetor keeps its bowl from being overfilled from the same low pressure mechanical pump.

Three scenarios:

1. Inline fuel pump that is not submerged in fuel - We can all agree that these fuel pumps are not reliable and have a bad reputation. You have to run a high pressure return line for this style fuel pump.

2.. In-take fuel pump - This is the best solution if you are capable of running new high pressure lines both to and from the tank / engine bay. You also have to run a high pressure return line for this style pump.

3. FiTech's Fuel Control Center (FCC) - This is a fuel pump submerged in fuel that is mounted in the engine bay. When used with FiTech EFI there is no need to run a high pressure line back to the fuel tank. This is a good solution if you do not want to change the fuel and vapor lines to/from the tank. Technically this can be reversed easily as well, perfect solution if you have a numbers matching car and may someday put the carb back.

The FCC vapor out does not leak fuel when you have everything setup correctly, it is only vapors that come from it. There is no high pressure return line that comes out of the FCC. Essentially the FCC accepts the same amount of lower pressure fuel that a carburetor would accept. The FCC (just like a carb) can keep its fuel bowl full and stop the flow of fuel from the low pressure fuel pump when it is not needed, that way the mechanical pump can use the return fuel line (if your car has that) or simply hold the fuel pressure (how fuel pumps work without a return line). The FCC creates high pressure from their fuel bowl (which is much bigger than a carb fuel bowl) and provides the exact amount of fuel the throttle body needs which is why when you use this setup you do not need a high pressure return line. I have been using the FCC with my FiTech throttle body since Fall of 2015 without issues.

I was actually referring to the FCC. I was unaware it contained a needle and seat like a carb here. But you still have to run the pulse width modulation with that pump. It's a deadhead system from the command center to the head unit. If you are attempting to run the pump at full voltage all the time, you create large pressure spikes that will damage the pump.

The FiTech head units ship calibrated for a frame mount pump that runs it at around 94% all the time. Any additional fuel that is not needed at the head unit with this type of system is returned to the fuel tank. The FCC on the other hand is a deadhead system from the command center to the FiTech head unit. If you don't setup the system to reduce and modulate the amount of fuel delivered you end up sending a lot more fuel and building a lot of pressure. People are reporting seeing well over 80 psi in some circumstances.

What really becomes an issue in this situation is something like a loaded WOT run where that fuel starts being utilized as needed, then you shut the throttle and have a wall of fuel and pressure slamming into the head unit. You end up stopping the flow to near zero as the injectors close, back feed the pump which causes cavitation, which can damage or destroy the pump's impeller.

FiTech states to set the PWM in the controller and use a value of 40 on the FCC. This means it's commanding the pump at an initial load of 40% and it will increase and decrease that based on fuel demand.

http://fitechefi.com/fitech-uploads/...tionFiTech.pdf

Originally Posted by gassman_67

What is the preferred location of the O2 bung on an TH400 equipped GTO?

I used the header collector reducer for my o2 sensor. As a rule of thumb you want the o2 sensor as close to the head as possible, while also having it sense as many cylinders as possible.

The closer the o2 sensor is to the combustion event, the faster the unit can respond to changes in commanded vs actual AFR. The more input signal you give it from more cylinders, the more accurate fueling will be.

So it's kind of a trade-off of speed vs accuracy. The most accurate place to put the o2 is in a cross-over if your vehicle has that type of exhaust. However because this is far downstream, the system can't react as fast to lean or rich mixtures. So you split the difference and lose half the cylinders but move the sensor closer to the combustion chambers.

If you're running a manifold like the RARE pieces or even factory logs, place the o2 sensor just aft of the manifold in the down pipe.

[Squidward]

Originally Posted by JLMounce

I used the header collector reducer for my o2 sensor. As a rule of thumb you want the o2 sensor as close to the head as possible, while also having it sense as many cylinders as possible.

The closer the o2 sensor is to the combustion event, the faster the unit can respond to changes in commanded vs actual AFR. The more input signal you give it from more cylinders, the more accurate fueling will be.

So it's kind of a trade-off of speed vs accuracy. The most accurate place to put the o2 is in a cross-over if your vehicle has that type of exhaust. However because this is far downstream, the system can't react as fast to lean or rich mixtures. So you split the difference and lose half the cylinders but move the sensor closer to the combustion chambers.

If you're running a manifold like the RARE pieces or even factory logs, place the o2 sensor just aft of the manifold in the down pipe.

Ha Ha! I was going to ask this question, and saw that I missed the last few posts. I was trying to figure where to put the O2 sensor as well. I am running Hooker Comps, full length headers. If I am reading this right, I will put the bung in the header collector just upstream of the collector outlet flange. I just installed some header buddies on my pipes. It would be easier to drop the pipes instead of the header, but ya gotta do what ya gotta do! I guess it would be best to NOT have the sensor in an area that might be susceptible to small leaks (downstream of collector flange). Thanks!

[JLMounce]

Yes it's absolutely critical that there are no upstream exhaust leaks of the oxygen sensor. This will cause rich fueling as the system compensates for unmetered air in the exhaust.

You should also take care to route the oxygen sensor pigtail as far away from the cap/rotor and any plug wires as possible. This will cut down on RF interference that can cause fueling anomalies.

[gassman_67]

Originally Posted by Squidward

Ha Ha! I was going to ask this question, and saw that I missed the last few posts. I was trying to figure where to put the O2 sensor as well. I am running Hooker Comps, full length headers. If I am reading this right, I will put the bung in the header collector just upstream of the collector outlet flange. I just installed some header buddies on my pipes. It would be easier to drop the pipes instead of the header, but ya gotta do what ya gotta do! I guess it would be best to NOT have the sensor in an area that might be susceptible to small leaks (downstream of collector flange). Thanks!

I'm going install Doug's ceramic headers, I don't wan't to install the bung in the header, but just behind the collector.

[Squidward]

Originally Posted by gassman_67

I'm going install Doug's ceramic headers, I don't wan't to install the bung in the header, but just behind the collector.

I would prefer just aft of the collector flange, but want to eliminate chances of a leak there. I have always had good luck with header buddies (no gaskets needed), but have never been able to fully qualify their sealing abilty, especially as it pertains to O2 sensors.

[1980 TA]

Got everything installed and survived the first test drive with no hiccups. Started off with low speed flat town driving and worked up to low speed hills and finished with highway driving. No full throttle runs yet, but some moderate accel runs in the higher gears. Drove it about 45 mins straight and it never got over 164 degrees. Heat soaked to 180 upon shut down and fired right up.

To get the shaker to fit, I had to remove the 1 inch carb spacer I had been running and use a 1 inch air cleaner spacer. I had to use the 90 degree fitting into the throttle body instead of the 45 but it cleared by about 1/4 inch. Shaker sits very nice in the hood opening.

I had to open the idle screw a bit to get the IAC numbers down where they should be, but I expected that.

The only real issue I am having is the speedhut AFR gauge is reading way off compared to the FI Tech. The gauge shows 18 when the handheld shows 14.5. It goes rich when the ECU does and comes back as it adjusts back to 14.5 Both sensors are in the same exhaust pipe within 2 inches of each other. I'd like to get that figured out but so far so good. The rest of the speed hut gauges and the handheld are almost spot on.

[angelo]

The Bosch sensor that fitech uses is 4.2, lsu so if your other AFR gauge uses the newer 4.9 lsu then that may be the difference. I saw the same thing with my AEM air fuel ratio gauge which uses the 4.9 Bosch sensor. Also the speed at which the reading is presented may be different, and a good system will go from rich to lean very quickly.

[Mace1971]

Originally Posted by angelo

The Bosch sensor that fitech uses is 4.2, lsu so if your other AFR gauge uses the newer 4.9 lsu then that may be the difference. I saw the same thing with my AEM air fuel ratio gauge which uses the 4.9 Bosch sensor. Also the speed at which the reading is presented may be different, and a good system will go from rich to lean very quickly.

FiTech now use the 4.9 sensor. I think they changed about six months ago. As far as I can tell the only way to know which yours has is to look at the sensor itself.

[angelo]

That is awesome they are now using the newer Bosch sensor. 4.9 is better.

If both gauges refresh their display with the same frequency (e.g. every 500ths of a second) they they should be reporting approximately the same.

You may have the opposite as well, fitech using a 4.9 and the gauge using 4.2.

[FrankieT/A]

is the 4.9 and the 4.2 interchangeable on the FITech? Or is that like a next generation thing and I bought my system too soon?

[Mace1971]

Originally Posted by FrankieT/A

is the 4.9 and the 4.2 interchangeable on the FITech? Or is that like a next generation thing and I bought my system too soon?

I believe the electronics are different so not interchangeable but FiTech would need to give a definitive answer.