Anyone having this FiTech Issue?

[rguest3]

Since adding the Relay for the Fuel Pump, the FiTech system cannot control the Voltage to the fuel Pump anymore. correct?

 

[68stang73]

A relay is like a light switch. It needs you to flip it on and off. So fitecs fuel pump wire is what turns the switch in and off. Resulting in no load on the fitech wire.

 

[rguest3]

I understand what a Relay does.

With a Relay installed the FiTech system will not longer be able to control the Voltage to the Fuel Pump. I think I have read somewhere (possibly another FiTech thread here) that the FiTech system is able to limit the intake of fuel from the mechanical pump, similar to a fuel regulator, to the Command Center. This is done by controlling the voltage to the Command Center.

 

[68stang73]

Ahh good point. Gotcha

 

[68dustin]

I haven't drove mine yet with the new welded ground. I'll report back tomorrow and let you know if my problem is fixed.. last resort before I send it back.

 

[RedLeg0811]

I understand what a Relay does.

With a Relay installed the FiTech system will not longer be able to control the Voltage to the Fuel Pump. I think I have read somewhere (possibly another FiTech thread here) that the FiTech system is able to limit the intake of fuel from the mechanical pump, similar to a fuel regulator, to the Command Center. This is done by controlling the voltage to the Command Center.

There was another thread that I had asked about using a relay on the pump. I had remembered reading one of the guys in this thread talking about how FItech had him put a relay on his fuel commander.

Anyway when I posted asking about a relay I had forgotten that there was voltage regulation to control speed until another gentleman reminded me and said it wouldn't work with a relay.

I started wondering after rereading about a relay being used on the FC. I work at a Semi truck test facility and so I went to ask one of my electrical engineer friends that does this stuff for our trucks. As soon as I said relay he said, keep the relay out as the voltage regulation will not work through the relay.

 

[bsquared]

I haven't drove mine yet with the new welded ground. I'll report back tomorrow and let you know if my problem is fixed.. last resort before I send it back.

Holy Sheeit, Dustin. That's one wicked looking engine bay, brother!

 

[bteutsch]

I understand what a Relay does.



With a Relay installed the FiTech system will not longer be able to control the Voltage to the Fuel Pump. I think I have read somewhere (possibly another FiTech thread here) that the FiTech system is able to limit the intake of fuel from the mechanical pump, similar to a fuel regulator, to the Command Center. This is done by controlling the voltage to the Command Center.

The FITECH system uses (PWM) Pulse Width Modulation to control the voltage that runs the high pressure EFI pump in either the command center, or frame mounted, or in tank pump. It can idle the pump when you don't need the full amount of pressure the pump can deliver by varying the voltage that the pump receives, which can help the pump run cooler. The pressure from the mechanical low pressure pump is regulated in the command center by a float system with a needle valve and seat. Just like a carburetor. I don't think it will work through a standard relay either. I was told to add a relay to help with a problem I was having with the sub harness melting. I guess I need to ask Bryce. But from what I've read the standard relay can't switch on and off fast enough to accomplish the PWM.

 

[.94 OR]

The FITECH system uses (PWM) Pulse Width Modulation to control the voltage that runs the high pressure EFI pump in either the command center, or frame mounted, or in tank pump. It can idle the pump when you don't need the full amount of pressure the pump can deliver by varying the voltage that the pump receives, which can help the pump run cooler. The pressure from the mechanical low pressure pump is regulated in the command center by a float system with a needle valve and seat. Just like a carburetor. I don't think it will work through a standard relay either. I was told to add a relay to help with a problem I was having with the sub harness melting. I guess I need to ask Bryce. But from what I've read the standard relay can't switch on and off fast enough to accomplish the PWM.

Was the wiring that melted the power to the pump, or did it feed power to the EFI controller which powered the pump? I haven't received mine yet, but wondering if the EFI needs a relayed full power so that it can then regulate the FCC.

 

[68dustin]

Well, I welded the ground to the car, made it about 5 miles and it started doing it again. So I decided to eliminate all possible things and checked my wiring. I turned off the fan controller and rewired my electric fans to how I had them before the efi. So far I think it was the fan controller in the efi unit. The ground wires from the efi unit to the relays on the fan are stupid small. Sucks I cant control them from the car, but if it just works ill be happy. Ill put some more miles on it and keep you guys updated. So right now I'm pretty much just using the efi unit and no timing control, fan control and im using the electric pump (not command center)

 

[bteutsch]

Was the wiring that melted the power to the pump, or did it feed power to the EFI controller which powered the pump? I haven't received mine yet, but wondering if the EFI needs a relayed full power so that it can then regulate the FCC.

It was only melting in the plug. None of the other wiring was melting. I would get an intermittent power loss. Wiggling or unplugging and reconnecting it would solve the problem at first, but as I kept using the system the problem got worse until it would only work for a few minutes. They suspected a poor ground at the negative on the command center was putting an extra load on the harness. I could see that being the issue, for one I used an existing sheet metal screw for the ground. It's also on my core support. The ground is shared by my headlights, they work fine, however they are on relays also. I'm tempted to jumper a ground from the sheet metal screw to the frame and remove the relay and see if the problem comes back. Relay is on the orange fuel pump wire, the melting was occurring on the main red power pin in the plug. No problems since the relay with melting in the plug.

 

[jurob]

Dustin,
Hope it's fixed for you.

Kind of sucks not being able to use the timing control, kind of defeats the purpose of paying extra for the power adder.

I'll be running a locked out duraspark distributor and hoping timing control works as I should be seeing 12 psi at 6k from an s trim.

Which dist are you running?

 

[68dustin]

Dustin,
Hope it's fixed for you.

Kind of sucks not being able to use the timing control, kind of defeats the purpose of paying extra for the power adder.

I'll be running a locked out duraspark distributor and hoping timing control works as I should be seeing 12 psi at 6k from an s trim.

Which dist are you running?

when I was running the blow thru carb I had the msd6a with the boost timing controller already. I'm kinda bummed about the fan controller though. I liked not having the fans running all the time. I'm running a msd distributor with 14degrees timing max 32, pulling 1 degree of timing per pound of boost for a total of 22 degrees.

 

[jurob]

How are you running air fuel under boost? Is the Fitech recognizing it or is it easy to command wot air fuel?

Sorry for the questions, I have my Fitech, just haven't started install. Should be start this weekend and have done shortly after.

 

[68dustin]

How are you running air fuel under boost? Is the Fitech recognizing it or is it easy to command wot air fuel?

Sorry for the questions, I have my Fitech, just haven't started install. Should be start this weekend and have done shortly after.



[/QUOte

the air fuel ratio's are great... under boost and at idle, way better than I could ever get my old blow thru carb to run.

 

[bsquared]

Brian,

The TPS reading will zero out every time you key off and allow the EFI save. What you are trying to achieve is to be at idle at operating temp with the IAC position between 5 and 10. To achieve this follow the steps below.

1. Bring engine up to operating temp. (around 180)
2. On the handheld go to Dashboard
3. Observe the TPS, IAC Steps, and Coolant temp readings
4a. If IAC Steps is zero and RPM is above target slowly close primary throttle blade screw (1/8 turn at a time) till IAC Steps start to raise to target 5-10 range.
4b. If IAC Steps are anything above 10 slowly open the primary throttle blade screw (1/8 turn at a time) until IAC Steps lower to the target 5-10 range.

NOTE: If TPS reading is 1.5 or higher the EFI doesn’t think the engine is in IDLE so it will raise IAC as a follower feature. To reset TPS just key off an allow EFI to power off. When EFI has saved the handheld values will go blank.

Bump post - I got a dedicated ground installed and re-routed my fuel lines. Having the same cutout issues as others have posted. My IAC steps are high (10+) right now, but I haven't gone through the tuning steps Brian shared earlier. (thanks for that) Will report back, good or bad.
Cheers, B2

 

[68dustin]

WELL .. car started doing it again... I'm out of ideas.. wish I would have just kept the blow thru carb

 

[68stang73]

I ended up on a Dodge forum. For life of me I don't remember which one. But I googled fitech issues or timing issues. And found it. But those guys are really getting deep into this system and making changes as needed. But ill tell you a good tuner guy can do wonders. Mine isn't druveable yet and I'm sure I'll have my own issues but some of the reading I've done most all issues were just setting it up and looking at the data log. I would contact fut CH and have them help you out for sure tho.

 

[work765]

Do I need to know what type of distributor and ignition before I start the install?

 

[DirtDonk]

If you're going to be running the 600 with it controlling the timing too, then yes you need to know whether yours is compatible or not. But you don't need to know just to run the EFi unit itself.
After all, if the distributor just happens to be not compatible, you can still run it in fuel-only mode and let the distributor do it's own thing like normal.

In general terms though, yes you would like to know what you have anyway. So you know which direction to go, or if you're going to need to get a different one.

So what do you have?

Paul