EFI conversion pro's & con's

[FatTireGoose]

Just picked up a '79 and considering a fuel injection conversion for the stock motor. Pro's I consider are increase in HP, easier starting and fuel economy but mainly being able to run regular pump gas and not having to search for ethanol free fuel. Only con I see is the price, Holley kits start around a grand. Thoughts, experiences?

 

[mrboatman]

I put the Holley Sniper EFI on my 69 F engine and it runs great, Easy install.
JP

 

[FatTireGoose]

I put the Holley Sniper EFI on my 69 F engine and it runs great, Easy install.
JP

Yup, the Sniper is the one I'm looking at. Did you notice many gains?

 

[mrboatman]

Yup, the Sniper is the one I'm looking at. Did you notice many gains?

Yes mainly in how it runs, much better, it starts a lot easier after shutdown when hot the restart is great just fires right up no flooding or vapor locking. I have not checked fuel mileage. Over all great improvment.
JP

 

[1911]

Yes mainly in how it runs, much better, it starts a lot easier after shutdown when hot the restart is great just fires right up no flooding or vapor locking. I have not checked fuel mileage. Over all great improvment.
JP

Where did you put the fuel pump for it (and which one did you use)?

 

[BrianSanDiego]

lots of efi info.
Holley Sniper 2 barrel conversion

Walbro makes some decent pumps. You'll need a 60psi pump with enough GPH for your motor, mounted low and near the fuel tank, and EFI fuel line.

 

[mrboatman]

Where did you put the fuel pump for it (and which one did you use)?

I used the pump that was included in the Sniper kit. I used the original fuel filter bracket to bolt the pump clamp to. This pic os before it was wired up.
JP

 

[jembourbe]

I've been running TBI fuel injection since 2007 or so. I switched from a factory carb that was working fine.

Fuel economy is the same. s***ty.

I don't know that efi makes a difference what kind of fuel you can run. It does sense whether your engine is efficiently burning whatever fuel you're running and make minor adjustments to your air/fuel ratio -- in real time -- but see point no. 1.

Power? Maybe a little more with the efi, maybe. But not much. It's a 2f after all...

It starts, runs and idles like a modern engine in the cold, which is good -- probably the thing I like best about it. No choke cable, etc. I'm running a stepper-motor idle air controller, and it is great for quick start and higher idle until warmwup in cold conditions.

It was a fun project but I wouldn't do it again. Here's why: the stock carb is great. Period. So is Rochester-based efi, but it still depends on a computer. We all do, for everything, but if the computer takes a crap you're calling the tow truck, and they don't like to tow on Ophir Pass. The stock set up is simple and easier to fix on the trail, in the field, or on the shoulder. For that reason I feel a little nervous when I'm driving it for more than a sushi run on the weekend.

@1911 - my pump is a Bosch in-line mounted on the outside of the frame rail inside of the the front pax tire.

 

[jembourbe]

The Holley kit looks pretty sweet though, for the price. And it's a whole lot simpler install (harness, etc.) than the AFI kit and the older options, which are all just minor variations on the Rochester TBI/Astro van theme.

 

[White Stripe]

Fuel efficiency and power increases from fuel injection mainly have to do with air fuel ratio and timing curve. From what I've seen of afi's timing curve u likely wont gain much fuel efficiency compared to a well tuned carb. Not sure about power increase. I have a custom timing curve programmed in mine and get 16mpg with 35s on the highway. U could go sniper with a recurved fj60 distributor and likely get good power and mpg increase.

 

[SteveH]

Search for AFI and read up those setups. I have AFI TBI with the modified FJ62 distributor (part of their kit). Probably $1500 total after all bits/changes/mods/improvements.

Far better throttle response - I can rip through the gears and am looking for 5th gear. Same gas mileage - possibly slightly worse, but commensurate with the power increase or I flog it harder. Excellent cold starts, although I'm fighting minor cold driveability issues at 30F. Always runs perfectly when fully hot. I took it to 12000' elevation this past summer and it ran/started great - no belching black clouds as with the carburetor or stalling on hard rock hits. Hot restarts are a breeze instead of a gamble - in fact, the hotter the day, the better it runs.

I used to rarely drive my 40 except on colder days because it was such a gamble. I can now enjoy it any time. I should add that I rebuilt the factory carb and fought with the truck ever since Ethanol was put in fuel.

I would have to drive another EFI setup to say whether one was better than the other.

Steve

 

[1911]

U could go sniper with a recurved fj60 distributor and likely get good power and mpg increase.

I have AFI TBI with the modified FJ62 distributor (part of their kit).

Since I'm already running a Jim C.-recurved FJ60 distributor, I like being able to keep it. Personally I wouldn't do an EFI conversion expecting more power or much of an increase in fuel economy, I just like the idea of being able to drive from Texas to the San Juan Mountains and back without losing so much power at altitude, and not having to worry about stalling on very steep inclines.

 

[Dizzy]

If you install a one, or two-wire O2 sensor in your exhaust, and an A/F gauge to accompany your carb, then you have something from both worlds.

I'm not quite there yet with the stock carb, but re-jetting a Weber can be done during your journey without even spilling gas on the exhaust manifold. Choke adjustments can help if you need enrichment

Because EFI measures an aggregate of exhaust, it can't deal with the inconsistency across all of the cylinders. Valve adjustments, spark and plug problems, bad compression, and manifold vacuum leaks will ruin your best efforts for fuel delivery upgrades regardless of type. EFI is awesome, though, don't get me wrong.

I'm skeptical of any non-factory configuration in how it deals with spark timing. But, I don't think that my original equipment is still in proper working order, either.