Wanted to share my novice experience with converting to EFI on a ’77 F150, 351M. I realize this mod is blasphemy for some but to me it wasn’t a big deal since it doesn’t materially alter the vehicle in a way that can’t easily be reversed. It’s been in for a few weeks now and I have NO complaints. It starts smooth and easy even as the temp here has been as high as 60 in the morning and as low as 26. Idle is super smooth. Throttle response is snappy. Smooth acceleration all the way through. Bonus – I no longer hear that annoying “our garage smells like gas” DAILY commentary anymore!

The Goods:

• FiTech Go Street EFI 400HP
• Walbro Inline Fuel Pump (yes the kit above comes with one but read on…)
• Fuel Pump block-off plate
• Air Cleaner spacer (to give it a ¾” lift)

The Process:Obviously the EFI kit comes with instructions and they are VERY easy to follow. I’ll just call out a few notes specific to my installation.

1. Needs an O2 sensor installed in close proximity to the collector area. Screenshot of mine is below. This was a bit of a struggle to drop the exhaust enough to get an angle on it. They want it to be 10 degrees or higher from level. Presumably so it doesn’t get as much gunk on it. Mine isn’t quite right as it’s too horizontal. I’m getting new exhaust soon so I’ll let the shop worry about drilling a new/better location.
   
2. Needs a coolant temp sensor. I've read complaints that the EFI kit hijacks the connection on the existing coolant temp sensor thereby rendering the in-dash gauge useless. However, the kit comes with a coolant temp sensor so I found an open port and installed it. Now the EFI has it's own sensor and I didn't have to sacrifice my dash gauge.
3. Requires inline electric fuel pump so I had to remove the mechanical and use a block off plate.
4. The Aeroflow pump they provided was louder than my Flowmasters. It wasn’t just during startup but constantly. I ordered the Walbro to swap it out. The Walbro fit the Aeroflow bracket perfectly and it whisper quiet. Problem solved.
5. Requires a fuel return line. They provided fuel line that I used for the feed to the throttle body. Then used the original hard line for the return. Issue: There’s nowhere to put the return line into the tank. I didn’t want to drill the tank so I opted to install the return into the fuel filler hose. There is a Moroso kit for this BUT that’s for 2” lines whereas mine is 2.5”. Ended up flattening out a part of the metal portion of the fuel filler doohickey and installed the elbow they provided in the kit. Photos below of the result. Seems to work as designed. ‘Merica.
   
   

I think that’s it. Hope this helps others to see what I did and/or should have done.

 

.......not 100% sure you (or the computer, I should say) will be all that happy with the temp sender location if it gets REALLY cold, but it might be fine. In the neck like that is downstream of the thermostat, so it might not read right before the thermostat opens.

I'm wanting to do the same thing on one as well - haven't decided between FITech and a Holley Sniper. What was the decision-maker for you? And you're perfectly happy with the fuel system setup? THAT looked like the worst part, lots of hole-boring and in-tank pumps, or that big fuel manager under the hood. Yours looks SO simple, and no reason it won't work fine.... I do have dual tanks, I was planning on running a second, identical switcher valve and running it stacked, 1 for delivery, 1 for return, or possibly just adding a 6-port, but those take some wiring. Either way - looks great! How's the performance/mileage?

 

Hey Jake - You may be right on the temp sensor location. I'll keep an eye on it. So far everything is operating very well though so fingers crossed.

I chose the FiTech mostly because it was a recommendation from a friend that I trust. I watched the videos, scoured many forums, and talked to some folks at a local car club. FiTech, as a company, exists specifically because of this kit. Whereas the others are name brands that have been around a while and are also doing EFI almost playing catch-up. I like innovators and FiTech seemed the most innovative. I could be wrong but that was part of my thought pattern.

You are 100% correct that the fuel pump and return line were easily the biggest pain. The Command Center was an option but an expensive one and added a component that I wasn't interested in seeing under the hood. I definitely would have preferred to stay with the mechanical pump if at all possible but that didn't seem to be an option. I don't like that I had to add an electric pump because in, I don't really like adding more things that could go wrong down the road. Simplicity is a huge reason why I like and have this rig!

That said, I am very happy with the result and would highly recommend it. I think the fuel efficiency is slightly better but that wasn't really a motivator for me. I do like throttle response and that it definitely does have! It runs smooth and solid.

The dual tanks are going to be a problem I think. That application may steer you more toward the Command Center option I would think.

 

That coolant temp location isnt gonna work. It will not see coolant flow until the thermostat is almost all the way open... No bueno. I put the coolant sensor in the old temp sender location (400 block) and moved the temp sender for the gauge to the thermostat housing.

EFI is a great upgrade and has really extended the driving season on my truck. I have had some tuning issues, in part I think due to my engine combo. Not a really wild motor but definitely not stock.

it is highly recommended to ditch the gasket and clamps on the 02 sensor and weld it right to the pipe as leaks there mess with 02 sensor readings.

 

You might be right on the dual tanks issue. But I REALLY don't want to add that command center. Another option that popped into my head was possibly putting 2 fuel pumps, 1 from each tank and Tee'd together, fed by a relay triggered by the tank switcher valve. Then I could use the existing switcher backwards for the return........ I'm guessing that the check valves in the "stopped" pump would be enough to stop any backflow to the "off" tank when the other pump is running.....That, and I like the idea of having a second fuel pump, should one take a dump I could switch 'em pretty easy in an emergency (same as you, rather stay as simple as possible). That's the same reason I'd really rather not go with in-tank pumps unless I have to.....

I like your logic on FITech, and that's what had me leaning that way. Appreciate it!!

 

Raceday28 I just want to say thank you for the thread, information and the pics to go along with it.

Please keep us posted on how it works out with the temp and O2 sensor.

 

You're the second to post the coolant temp sensor warning so I'll definitely keep an eye on it. So far so good though. But I live in a pretty temperate climate.

And you're right on the O2 sensor. I'm having Super 44's added in a few weeks and already told them I want a fitting welded in. Good call!

 

Awesome thread, considering doing same on my 77 400M she's warmed up a bit with cam etc... like the duel pump idea also.
Thank again.

 

Where did you hook the white wire up to? Also, how did you vent your gas tank?

 

White wire went to switched power. My tank has no vent but if you're asking about the return line I ran it back into the filler neck. Has been working very well!

 

Checking in to see if all is well with your fitech?

 

Your truck *should* have started smooth and easy and with a super smooth idle under those conditions before when it had a carburetor.

If it didn't, something wasn't right - perhaps the choke wasn't set correctly.


Again, your truck *should* have had snappy throttle response and smooth acceleration all the way through before when it had a carburetor.

If it didn't, something wasn't right - perhaps the accelerator pump was malfunctioning.


Your garage should *not* have smelled like gas, either.

If it did, something wasn't right or something was missing from your truck - perhaps the charcoal canister.


There is nothing wrong with EFI, and I am not against it, but the truth of the matter is there is very little difference between a properly functioning vehicle with a carburetor compared to a properly functioning vehicle with EFI.

 

People hopped on Fitech because it is cheap! It was not the first or the second self-learning EFI system shaped like a carburetor. It does seem to work quite well, so do most of the others.
Yup, carbs "should" do all of those things and sometimes they do...Most people aren't up to the maintenance to get the same season-to-season or elevation-to-elevation performance that a well set up EFI provides. For myself, my driving ranges regularly from 910 ft above msl to 10,495 ft above msl. I'm not going to change jets every hundred miles but the EFI will take care of most if not all of the change. I'm not going to have to change tuning when I drive into a new area with a different mandated fuel composition, either.
On a hot day take a walk across a parking lot full of cars. You will be able to smell an old car from 50 feet away, from the fuel evaporating out of the carburetor. Any EFI car that stinks like gasoline has a problem. I know, evap emissions rules started in or before 1971, but somehow the EFI cars don't put as much into the air. The evap emission system in your carbureted car should still be there after installation of EFI , you don't have to fabricate anything.

R.

 

As long as you have the stock thermostatic air cleaner in place and working properly, you *should* get the same performance from your carburetor regardless of the season.

Since a carburetor is a mechanical device, it simply *cannot* self-adjust to elevation changes like an EFI system can, so it will need a jet change for optimum performance. That is clearly an advantage for EFI. But people get way too carried away on this; it's not like a carbureted vehicle can't handle elevation changes at all. People drove their carbureted vehicles up and down mountains every day long before EFI.


Any carbureted vehicle with an evaporative emissions system that stinks like gasoline also has a problem. Most of the old cars you smell are worn out by now and need attention. Or, they have been modified by people who don't have a clue. With older carbureted vehicles, it is more common to see an engine modified with an open-element air cleaner, an oversized carburetor that often doesn't have a choke, a lumpy cam, and components like the charcoal canister and catalytic converter are often missing. Too many people try to "hot rod" their carbureted vehicles because it is easy to do and end up with a stinking mess that doesn't run correctly. Most people accept the fact that for an EFI system to run correctly, all of it's components must be in place and functioning correctly. But with carbureted vehicles, most people tend to ignore this same fact.

My own carbureted truck is parked in a garage, and it doesn't smell like gas nor has my Wife or anyone else complained of a gas smell. However, my engine is healthy, I have a thermostatic air cleaner hooked up and working, a stock-size carburetor that was designed to work with my particular engine, it is tuned correctly and has a working choke, a conservative RV-style cam, and the charcoal canister is hooked up and functional.

In other words, it runs just as good as my other two vehicles with EFI - and it doesn't stink.

 

Raceday28,

You said "The Walbro fit the Aeroflow bracket perfectly and it whisper quiet."
What model is the Walbro you bought/use?