Vintage Mustang Forums banner

1 - 20 of 79 Posts

·
Registered
Joined
·
298 Posts
Discussion Starter #1
It's been a long story.
I installed the system on my 68 with a 331 stroker and have been having nothing but problems. It never ran right from the get go, it stumbled on acceleration because it was going way rich. While trying to solve the problem, the handheld died, the screen went white and stayed there. FiTech sent me a new one, this next one had a software glitch that wouldn't let me access the pro tuning page, the FiTech guys wanted me to send them the handheld and the throttle body back to them so they could figure out the problem, so I did.
Now I have a new handheld and my old throttle body back, the car still goes way rich and stumbles even though I have adjusted the accelerator pump settings. Now the worst part, while driving around, the car will randomly die, the fuel just cuts off and I have to pull off the road. The car will crank over but will not start. When I open the hood I can hear the fuel pump running in the command center, even though the key is off. I have to disconnect the battery, reconnect it and then the car will start right up. The FiTech guys have no idea what might be causing this problem, I just got off the phone with them after re-programing the ECU. After finishing that up my handheld died again, this time I think something is wrong with the power cord because the unit does not light up when plugged in.
All of this and the car still does not run right.

Sorry for the long rant
 

·
Registered
Joined
·
2,865 Posts
When I open the hood I can hear the fuel pump running in the command center, even though the key is off. I have to disconnect the battery, reconnect it and then the car will start right up. The FiTech guys have no idea what might be causing this problem, I just got off the phone with them after re-programing the ECU.
I've had this happened to me but I heard the fuel going through the TB when the key was out. I ended up cutting the wire that power the TB from the battery and spliced it back. Talked to FiTech and they didn't know what the cause was either. This was 2-3 months ago. Have not had that issue since.
 

·
Registered
Joined
·
467 Posts
Wow...I was pretty close to pulling the trigger on one of these, but it sounds like I might want to wait a year and let them address all of these gremlins.
 

·
Registered
Joined
·
1,165 Posts
Wow...I was pretty close to pulling the trigger on one of these, but it sounds like I might want to wait a year and let them address all of these gremlins.

They have been out there for over 2-4 years as I've seen them installed in Corvettes, Bronco's, etc. from other forums when I was doing my initial research. Sometimes there is a problem with a unit or two and nothing is perfect. I bought one and I'm in the process of installing it now. I did not go with the external Command Center that they sell, instead I went with a new tank and in-tank fuel pump.


I followed a thread on this forum where a member put in a Holley EFI, and at week 40 it still was not working. Others put in the same type unit and no issues.


I can empathize with the OP as having something installed that does not work as described is a PITA. I'm hoping that FiTech will help him get the issues addressed and corrected.
 

·
Registered
Joined
·
4,440 Posts
Have you checked your motor for vacuum leaks? Even a slight leak will cause an EFI system to not work properly, any EFI system.
 

·
Registered
Joined
·
1,165 Posts
Have you checked your motor for vacuum leaks? Even a slight leak will cause an EFI system to not work properly, any EFI system.

Agreed. In the instructions it does talk about putting this on a spread bore intake manifold, and the need for an adapter in order for it to not leak. Sorry, I don't know what type intake you have, spread or square bore, so I'm just pointing out what they said to look for.


As far as the fuel pump still running even with the key off, is the fuel pump wire to a keyed source so that it gets a constant +12 VDC even in run mode?
 

·
Registered
Joined
·
2,865 Posts
As far as the fuel pump still running even with the key off, is the fuel pump wire to a keyed source so that it gets a constant +12 VDC even in run mode?
The TB has 1 wire that goes straight to the battery and 1 that goes to a keyed source. Mine happened after I drove home and parked. Turned off the engine and can still hear the fuel circulating through the TB. Took the key out and still circulating. Opened the hood and cut the wire to the battery and it stopped. Then spliced it back and have not come back since then.
 

·
Registered
Joined
·
298 Posts
Discussion Starter #8
Agreed. In the instructions it does talk about putting this on a spread bore intake manifold, and the need for an adapter in order for it to not leak. Sorry, I don't know what type intake you have, spread or square bore, so I'm just pointing out what they said to look for.


As far as the fuel pump still running even with the key off, is the fuel pump wire to a keyed source so that it gets a constant +12 VDC even in run mode?
The intake is an Edelbrock F4B which is a standard square bore intake.
I checked all around the top of the motor for vacuum leaks and found none.
The power for the fuel pump comes direcly from the ECU which is located in the throttle body. The ECU has two power inputs, one is a wire that goes directly to the battery positive terminal. The other is a switched 12 volt source. I used the wire that goes to the + side of the coil, but not direcly. Since that is a resistor wire and only puts out about nine volts, I connected a relay so that the 9 volts will trigger the relay and deliver a full 12 volts from the battery to the ECU when the key is in the start or on position.
 

·
Registered
Joined
·
1,165 Posts
The intake is an Edelbrock F4B which is a standard square bore intake.
I checked all around the top of the motor for vacuum leaks and found none.
The power for the fuel pump comes direcly from the ECU which is located in the throttle body. The ECU has two power inputs, one is a wire that goes directly to the battery positive terminal. The other is a switched 12 volt source. I used the wire that goes to the + side of the coil, but not direcly. Since that is a resistor wire and only puts out about nine volts, I connected a relay so that the 9 volts will trigger the relay and deliver a full 12 volts from the battery to the ECU when the key is in the start or on position.

Thanks for getting back to me. I had to ask about the intake as I also need to make sure mine was a square bore. When I was looking at the FiTech I found that someone indicated that a few of the emission caps became split, might have even been qbui. That could be something to check for.


Are you using an external CDI box like an MSD 6A or other CD ignition? Are you having the system control the timing? Have you checked all the grounds as that could lead to electronic gremlins? I used to be an electronic tech and I know what problems that a poor ground could cause. Have you tried putting the ground wire directly to the negative side of the battery since that is also grounded to the engine?


There was also someone that said that one of their connectors had a pin that was not fully seated, and when they put the connectors together, a pin got pushed out. Can you double checked the pins to make sure everything is connected and inserted fully?


Again, sorry for all the questions, but that is the only way I know how to try to determine what could be at fault.
 

·
Registered
Joined
·
298 Posts
Discussion Starter #10
Thanks for getting back to me. I had to ask about the intake as I also need to make sure mine was a square bore. When I was looking at the FiTech I found that someone indicated that a few of the emission caps became split, might have even been qbui. That could be something to check for.


Are you using an external CDI box like an MSD 6A or other CD ignition? Are you having the system control the timing? Have you checked all the grounds as that could lead to electronic gremlins? I used to be an electronic tech and I know what problems that a poor ground could cause. Have you tried putting the ground wire directly to the negative side of the battery since that is also grounded to the engine?


There was also someone that said that one of their connectors had a pin that was not fully seated, and when they put the connectors together, a pin got pushed out. Can you double checked the pins to make sure everything is connected and inserted fully?


Again, sorry for all the questions, but that is the only way I know how to try to determine what could be at fault.
I am running an MSD ready to run distributor, no external box and the ECU is not controlling the timing.
I think all of my grounds are good, when I installed my engine and fuel system I was real careful about making sure I had good clean connections.
Thats a good idea about checking the pins on the main connector I will do that.
What has me puzzled is why would the fuel pump keep runnng when the key is off?
The ECU controls the pump so I am thinking there might be a software glitch.
There is no ground wire for the unit, the throttle body is grounded through one of the studs on the intake manifold and I checked to make sure that connection looked clean and was tight.
 

·
Registered
Joined
·
1,165 Posts
I am running an MSD ready to run distributor, no external box and the ECU is not controlling the timing.
I think all of my grounds are good, when I installed my engine and fuel system I was real careful about making sure I had good clean connections.
Thats a good idea about checking the pins on the main connector I will do that.
What has me puzzled is why would the fuel pump keep runnng when the key is off?
The ECU controls the pump so I am thinking there might be a software glitch.
There is no ground wire for the unit, the throttle body is grounded through one of the studs on the intake manifold and I checked to make sure that connection looked clean and was tight.

Since the unit has no dedicated ground, can you connect one from the TBI base to the battery ground cable. This will ensure that it is grounded to the battery, even though you have grounds.


With regard to the Command Center fuel pump running when the key is turned off. Since you have fuel pump on a key sourced relay it seems that the relay is stuck in the on position, causing the pump to continue to run. Have you thought about connecting the wire for the key source to another source like the "I" on the Start Solenoid to see if that helps or change the relay to see if the relay is bad?


Is the Command Center properly vented as that could cause a fuel starvation issue?
 

·
Registered
Joined
·
298 Posts
Discussion Starter #12
Since the unit has no dedicated ground, can you connect one from the TBI base to the battery ground cable. This will ensure that it is grounded to the battery, even though you have grounds.


With regard to the Command Center fuel pump running when the key is turned off. Since you have fuel pump on a key sourced relay it seems that the relay is stuck in the on position, causing the pump to continue to run. Have you thought about connecting the wire for the key source to another source like the "I" on the Start Solenoid to see if that helps or change the relay to see if the relay is bad?


Is the Command Center properly vented as that could cause a fuel starvation issue?
Pete
Sorry if I was unclear on my description.
The power for the fuel pump comes directly from the ECU, there is no external relay.
Battery power goes into the throttle body and then the ECU decides what to do with the fuel pump. It uses something called pulse width modulation to vary the speed of the pump as the demand for fuel changes while driving.

Thanks for working with me on this.
 

·
Registered
Joined
·
4,440 Posts
The intake is an Edelbrock F4B which is a standard square bore intake.
I checked all around the top of the motor for vacuum leaks and found none.
The power for the fuel pump comes direcly from the ECU which is located in the throttle body. The ECU has two power inputs, one is a wire that goes directly to the battery positive terminal. The other is a switched 12 volt source. I used the wire that goes to the + side of the coil, but not direcly. Since that is a resistor wire and only puts out about nine volts, I connected a relay so that the 9 volts will trigger the relay and deliver a full 12 volts from the battery to the ECU when the key is in the start or on position.
Just trying to help, but I would pick up a vacuum gauge (if you don't already have one) and check, that's the only way to be 100% sure. If the needle fluctuates you have an issue somewhere. Even a slight vacuum leak will confuse the crap out of an EFI system.
 

·
Registered
Joined
·
1,165 Posts
Pete
Sorry if I was unclear on my description.
The power for the fuel pump comes directly from the ECU, there is no external relay.
Battery power goes into the throttle body and then the ECU decides what to do with the fuel pump. It uses something called pulse width modulation to vary the speed of the pump as the demand for fuel changes while driving.

Thanks for working with me on this.


No problem, since we are not talking face to face communications can get spotty.


Doesn't the power to the ECU come from a switched source? I know that the main wiring connector gets hooked up to the "+" of the battery to keep all the settings, but the White wire from connector "A" gets connected to a switched source according to the instructions. This White wire is what gets the ECU to work when the car is running, and in turn gets the PWM to the fuel pump.


Where do you have the White wire connected to?


Thanks
 

·
Registered
Joined
·
1,165 Posts
Just trying to help, but I would pick up a vacuum gauge (if you don't already have one) and check, that's the only way to be 100% sure. If the needle fluctuates you have an issue somewhere. Even a slight vacuum leak with confuse the crap out of an EFI system.

It could even be a leak at the O2 sensor.
 

·
Registered
Joined
·
2,865 Posts
Well, since we're on the subject of problems, I have one that just happened to me today when I went out to lunch. Not really a problem according to FiTech since it had happened to me once before but just something in case others run into the same thing.

Was driving to pick up some lunch and as I drove out the parking lot, the handheld says: Flash Erase
Then it started counting up to 150 and then rebooted the handheld. Car was driving normal during all of this.
After the reboot, I wanted it to show large display but the unit was kinda possessed because it sometimes move 4-5 spaces when I only want it to move 1 space. Then the same when I try to move in reverse. I just unplugged and plugged the handheld back and it was behaving again. Didn't seem to wipe any setup but was a concern to me the first time it happened. This is the second time that it happened.
 

·
Registered
Joined
·
298 Posts
Discussion Starter #17
No problem, since we are not talking face to face communications can get spotty.


Doesn't the power to the ECU come from a switched source? I know that the main wiring connector gets hooked up to the "+" of the battery to keep all the settings, but the White wire from connector "A" gets connected to a switched source according to the instructions. This White wire is what gets the ECU to work when the car is running, and in turn gets the PWM to the fuel pump.


Where do you have the White wire connected to?


Thanks

I have the white wire connected to the secondary side of the relay, so when the primary side causes the relay to close, I get a direct connection between the battery and the ECU
The primary side is connected to the IGN switch.
 

·
Registered
Joined
·
298 Posts
Discussion Starter #18
Thanks for getting back to me. I had to ask about the intake as I also need to make sure mine was a square bore. When I was looking at the FiTech I found that someone indicated that a few of the emission caps became split, might have even been qbui. That could be something to check for.


Are you using an external CDI box like an MSD 6A or other CD ignition? Are you having the system control the timing? Have you checked all the grounds as that could lead to electronic gremlins? I used to be an electronic tech and I know what problems that a poor ground could cause. Have you tried putting the ground wire directly to the negative side of the battery since that is also grounded to the engine?


There was also someone that said that one of their connectors had a pin that was not fully seated, and when they put the connectors together, a pin got pushed out. Can you double checked the pins to make sure everything is connected and inserted fully?


Again, sorry for all the questions, but that is the only way I know how to try to determine what could be at fault.

I took a look at my pin connectors and they all looked good.
 

·
Registered
Joined
·
298 Posts
Discussion Starter #20
v1 did you have your car running with a carb and this manifold?

Larry
Yes, and it ran like crap. I have an A/F gauge mounted on the dash and it was running very lean.The carb was an old Holley that came with the car when I bought it.
That carb was so dirty and nasty looking I didn't want to rebuild it. When I did the switch to EFI the car ran much better but still has a few issues maintaining a constant A/F ratio.
 
1 - 20 of 79 Posts
Top