Fi tech - frame mounted inline fuel pump

[bteutsch]

Another good choice would be the Bosch 69100 pump, which was the OEM external pump Ford used from 85-89 on their pickups/Broncos/Rangers.

In April, I passed the 20th anniversary of using mine without issues with 130,000 miles on my EFI engine conversion. It originally came off of an '88 truck chassis from which I plucked it back in '97.

I had one issue climbing a steep hill in '97 where it lost its prime momentarily and one other climb that I can recall a year or two later. That was with a NWMP tank - after I switched to a BC tank and revised the pickup somewhat, I haven't had any issues.

I ran the truck out of fuel last summer - thankfully within walking distance of my house. When I refilled the tank, I determined I had ~0.5 gallons of fuel left in the tank. Not bad at all.

Todd Z.

Hey Todd, I'm looking at using the Bosch 69100 pump with the Fitech throttle body. Do I need to use a relay if I use this pump. Just read where if it pulls more than 15amps to use a relay. I haven't been able to find any specs on current draw for the Bosch pump.


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[NYLES]

Hey Todd, I'm looking at using the Bosch 69100 pump with the Fitech throttle body. Do I need to use a relay if I use this pump. Just read where if it pulls more than 15amps to use a relay. I haven't been able to find any specs on current draw for the Bosch pump.


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YES!...........clogged filter could overwork a pump and fry wires do the relay.

 

[bteutsch]

YES!...........clogged filter could overwork a pump and fry wires do the relay.

Thanks Nyles!!!!


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[toddz69]

X2 on the relay. I like to use OEM stuff as much as possible and my factory Ford harness has a relay in it for the pump.

Todd Z.

 

[bteutsch]

YES!...........clogged filter could overwork a pump and fry wires do the relay.

Hey Nyles or Todd, is there any reason not to use PWM with the frame mounted pump. If not do you have a recommendation on a solid state relay?

I had to use PWM with the command center or it would overheat. And PWM doesn't work through a standard automotive relay.


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[Cortez]

Fitech support team told me to turn off the PWM with the Bosch 69100 so with or without a relay it's no PWM. Mine works just fine with pwm turned off but now I'm wondering about adding the relay to be safe.

 

[toddz69]

Hey Nyles or Todd, is there any reason not to use PWM with the frame mounted pump. If not do you have a recommendation on a solid state relay?

I had to use PWM with the command center or it would overheat. And PWM doesn't work through a standard automotive relay.


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I don't know what PWM is.

Todd Z.

 

[AZ73]

I don't know what PWM is.

Todd Z.

Pulse width modulation - Solid state speed controller instead of mechanical off/on relay. But its really a speed controller so I'm not sure why you would use it instead of a relay. It's typically used in race engines that need lots of fuel when racing so pump needs to be running full speed and lots of pressure, but turn down the speed and pressure when not wide open throttle. It's basically a fuel pressure adjuster.

 

[NYLES]

Pulse width modulation - Solid state speed controller instead of mechanical off/on relay. But its really a speed controller so I'm not sure why you would use it instead of a relay. It's typically used in race engines that need lots of fuel when racing so pump needs to be running full speed and lots of pressure, but turn down the speed and pressure when not wide open throttle. It's basically a fuel pressure adjuster.

Mines off no issues

 

[bteutsch]

Mines off no issues

Good to hear!! I picked up a junkyard pump from an 85 F150 yesterday. I mostly got it for the mount. The Bosch pump is supposed to fit perfectly in it. I may try the pump and see if it works. Have to pick up some EFI fuel hose, pre filter, etc and see what happens. Already have a relay for the fuel pump.


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[KyleQ]

The PWM is one of the features that sets the FiTech apart, not using it is a shame. It turns the pump off of speeds it up depending on demand. If you are going to relay it then at least run a solid state relay so you can take advantage of the PWM feature.

I'm not running a relay for that listed pump I'm using - pump is wired directly to the power wire as FiTech intended it to be.


FUEL PUMP CONTROL
By FiTech August 19, 2016 61 Comments
The FiTech ECU for Go EFI systems has a special driver circuit that will drive the fuel pump directly, which means that an external relay is not needed. This driver circuit allows both PWM control (pulse width modulated), and direct internal relay drive of the fuel pump. This allows the voltage to be reduced when the fuel demand is low, such as at idle and light cruise.

Pump Prime time = At Key On, the pump is turned on for this much time, which allows the throttle body to be purged of air pockets, and for the pressure to be built up to the normal operating pressure.
TPS for PUMP ON = If the throttle is opened above this position, the internal relay is turned on to supply full power to the fuel pump.
RPM for PUMP ON = If the RPM is above this speed, the internal relay is turned on to supply full power to the fuel pump.
PWM Low Flow = When the fuel flowrate is low, and all of the other conditions for allowing PWM control to be met, this is the percentage of duty cycle that is used. Set this such that fuel pressure doesn’t drop below the rated fuel pressure of the system.

 

[bteutsch]

I have another question, I think Fitech recommends a 3/8 fuel supply line, and 5/16 minimum return, I pulled this high pressure motorcraft pump from a junk yard it looks like it's supplied by 5/16, I don't have to use it, and it may not be any good. However with dual tanks I was going to use one of the 3 port fuel selector valves to split the tanks, it has 5/16 barb fittings. So will 5/16 flow enough fuel for the Fitech on my mostly stock engine, with either this motorcraft pump or that Bosch 69100? Or is there a 3 way electric valve that has 3/8 fittings? I can replace the output fitting on the motorcraft pump, but the supply end is made on so still a restriction. Any ideas would be appreciated!!!!


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[toddz69]

I have another question, I think Fitech recommends a 3/8 fuel supply line, and 5/16 minimum return, I pulled this high pressure motorcraft pump from a junk yard it looks like it's supplied by 5/16, I don't have to use it, and it may not be any good. However with dual tanks I was going to use one of the 3 port fuel selector valves to split the tanks, it has 5/16 barb fittings. So will 5/16 flow enough fuel for the Fitech on my mostly stock engine, with either this motorcraft pump or that Bosch 69100? Or is there a 3 way electric valve that has 3/8 fittings? I can replace the output fitting on the motorcraft pump, but the supply end is made on so still a restriction. Any ideas would be appreciated!!!!


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Yes, a 5/16" line should be just fine assuming your engine is stock, or nearly so. I'm sure there is plenty of chatter on the inter webs about how much hp a 5/16" line can feed - my gut feeling is that you're good up to at least 300 hp with it. The Bosch 69100, which Ford used on everything from 2.3L fours to 460s, has the 5/16" input fitting as well.

Todd Z.

 

[bteutsch]

Yes, a 5/16" line should be just fine assuming your engine is stock, or nearly so. I'm sure there is plenty of chatter on the inter webs about how much hp a 5/16" line can feed - my gut feeling is that you're good up to at least 300 hp with it. The Bosch 69100, which Ford used on everything from 2.3L fours to 460s, has the 5/16" input fitting as well.



Todd Z.

Glad to hear that, will make things much easier. I don't think I'm anywhere near 300hp, just the original 1971 factory 302 bored .30 over with Edelbrock performer RV type cam, and performer intake. Has factory heads, does have ceramic coated headers and duraspark ignition. Don't even know if I'm pushing 200hp.


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[bteutsch]

The PWM is one of the features that sets the FiTech apart, not using it is a shame. It turns the pump off of speeds it up depending on demand. If you are going to relay it then at least run a solid state relay so you can take advantage of the PWM feature.

I'm not running a relay for that listed pump I'm using - pump is wired directly to the power wire as FiTech intended it to be.


FUEL PUMP CONTROL
By FiTech August 19, 2016 61 Comments
The FiTech ECU for Go EFI systems has a special driver circuit that will drive the fuel pump directly, which means that an external relay is not needed. This driver circuit allows both PWM control (pulse width modulated), and direct internal relay drive of the fuel pump. This allows the voltage to be reduced when the fuel demand is low, such as at idle and light cruise.

Pump Prime time = At Key On, the pump is turned on for this much time, which allows the throttle body to be purged of air pockets, and for the pressure to be built up to the normal operating pressure.
TPS for PUMP ON = If the throttle is opened above this position, the internal relay is turned on to supply full power to the fuel pump.
RPM for PUMP ON = If the RPM is above this speed, the internal relay is turned on to supply full power to the fuel pump.
PWM Low Flow = When the fuel flowrate is low, and all of the other conditions for allowing PWM control to be met, this is the percentage of duty cycle that is used. Set this such that fuel pressure doesn’t drop below the rated fuel pressure of the system.

Do you have a part number or a specific solid state relay? I don't know anything about them. Looking for one that for sure works with the fitech system. I see a Hella H41773001 on summits website that is a negative control relay. one of the reviews says it works for PWM, not sure how to wire it up. I have wired regular relays.

 

[KyleQ]

It looks like this should help - I don't think you need one, but here is some great info.

 

[bteutsch]

Thanks KyleQ


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[AZ4x4]

Can anyone post some pictures of how they get the fuel out of the tank and to the inline Pump? RIght now I just have some fuel line piped into the tank through a bulkhead I installed where I tapped the tank. I'm wondering if what I did is the best method. Thanks.

 

[Broncobowsher]

Use the stock fuel pickup that you would normally use with a carburetor.

 

[Tulsa76bronco]

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