EFI vs Propane pros and cons

[77broncodriver]

Hey there, Ive been having a hard time with my fuel system. I put in a new 306 crate engine that really nice compared to the old 302. at first i got a demon carb, a little big, it was a 625, got it rebuilt and everything and it ran great, it was very powerful, compared to before that is, but after 1 offroad trip it wasn't liking the hills or bumps and kept quitting and ended up rebuilding it twice and drained the tank once and ended up boiling gas over the last trip and then wouldn't run after 2000rpm.

then a friend gave me an old holley projection kit and i got that running and its way better on the hills and everything but it is so gutless, it feels less powerful than the old 302 but ive kept it for the past month because its been reliable. now since i get 7.5 mpg and am a broke senior in high school using my bronco as my daily driver it wont cut it for college so i want to turn it into a weekend driver/ trail rig and get a commuter car.

now enough of that, i want to spend as little money as possible so i can get new tires and lockers and other things and im not sure which would be better, piecing together a ford efi system, probably coming in around 1000 bucks, dual fuel, propane and carb and use the demon for cruising around town, that also comes out to be a little over a grand after the kit plus rebuilding the carb again, or lastly a buddy has a strait propane setup i can probably get for cheep, will this work just for driving weekends and to and from the trails? would my 7.5 mpg at $4.50 a gallon be about the same as propane? any more ideas i am not thinking of can help too, its a big decision because i dont want to waste money again.

Thanks Evan

 

[lil-bronc]

I have had both. The propane was cheap setup and worked well. But the filling of the bottles was a pain in the arse.

The advantage to propane is it is a very simple system and has very little problems. You could carry two diaphragms and it is totally rebuild able from anywhere. Only one wire needed. The disadvantage is you really never know how much fuel you have. Filling bottles is a pain. And if you run out, good luck finding someone that has extra propane for you.

The advantage or EFI is that it just works. Even using a stock wiring harness and eliminating what you don't need and adding resistors where you need is fairly easy. There is a device that reads errors. The disadvantages is that it cost more, I only paid about $100 more from my propane setup. Not as easy to adjust. But they do sell aftermarket kits that will allow you to tweak your system if you need too.

Hope this helps.

 

[TwoDalesDad]

You could double your mileage if you were to use a carburetor sized for your engine. if you were to try a holly450 with the right jets...your economy would come back...or not!

 

[bronco-billy-66]

I have had both. The propane was cheap setup and worked well. But the filling of the bottles was a pain in the arse.

The advantage to propane is it is a very simple system and has very little problems. You could carry two diaphragms and it is totally rebuild able from anywhere. Only one wire needed. The disadvantage is you really never know how much fuel you have. Filling bottles is a pain. And if you run out, good luck finding someone that has extra propane for you.

The advantage or EFI is that it just works. Even using a stock wiring harness and eliminating what you don't need and adding resistors where you need is fairly easy. There is a device that reads errors. The disadvantages is that it cost more, I only paid about $100 more from my propane setup. Not as easy to adjust. But they do sell aftermarket kits that will allow you to tweak your system if you need too.

Hope this helps.

What he said^^
I have both. And like both allot better than a carb. I prefer the efi, but both work fine. Just dealing with the bottles sux. And I run two bottles in my crawler, they take up allot of room

 

[77broncodriver]

How long do you think a bottle of propane can last? If everything goes to plan, the bronco will just be for when I come back from college and go to Hollister and drive around town. If a propane only setup would work I would use that because I could probably do it the cheapest

 

[OX1]

How many gallon tank do you have now and/or do you fill up @ some point during your current trips? Even the large forklift tanks are about 10 galllons, so I'm guessing you may even need 3 if your mileage stays that bad.

Even if you up it to 10 MPG (with the pane) on the way to/from the trails and 5 offroad, 2 tanks gives you max range of 150 miles round trip and 10 miles offroad, that enough?

 

[Apogee]

A little off-topic, but I'm not really clear how you can get 7.5 mpg with a 306, you must be dumping fuel out the exhaust or driving it like you stole it, WOT all the time. Just because you have/had an oversized carb, that doesn't explain the mileage since your engine only has a certain volumetric efficiency, so it can only pull in so much fuel/air per cycle regardless of carb size. I would expect poor throttle response off idle due to low-velocity air flow through the carb, but not 7.5 mpg. My friend's 500 HP 302 race motor does about that well when racing...how big is that cam you're running?

 

[texashcane]

I use up about one 10 gallon tank per day when I am wheeling. If we hit it hard, I might use a little more. That being said. Most of the places I wheel are self contained parks and there is not a lot of driving to get to the trail and most of the trails are pretty short.

 

[G's Baja Bronco]

A little off-topic, but I'm not really clear how you can get 7.5 mpg with a 306, you must be dumping fuel out the exhaust or driving it like you stole it, WOT all the time. Just because you have/had an oversized carb, that doesn't explain the mileage since your engine only has a certain volumetric efficiency, so it can only pull in so much fuel/air per cycle regardless of carb size. I would expect poor throttle response off idle due to low-velocity air flow through the carb, but not 7.5 mpg. My friend's 500 HP 302 race motor does about that well when racing...how big is that cam you're running?

x2, 33" tires, stick, 306 I would imagine more MPG! in mine I choose 91 Mustang 5.0 EFI, the pricey part was the fuel tank! all else I found used, between harness, explorer intake (with all sensors) computer and fuel lines I got about 300 dlls, the BC tank I got from some one who did not install it, basically new for 350 locally.

 

[77broncodriver]

I'm getting 7.5 with the projection system, it's running way rich and just spits gas out, I really don't like the performance and fuel economy and I don't want to go just carb again because it will do terrible off road, are there like 30 gal tanks for propane? I'm turned off on all fuel injection except the mustang stuff but it seems so expensive, and the cam is just a e303, not very big, and I never got to check the mpg with the carb

 

[G's Baja Bronco]

sounds like you already have the high pressure fuel requirement for the EFI, find an explorer on the wrecking yard and take the complete intake, injectors and all. then find a stang and take the harness and computer, eliminate the smog and AC stuff and go! well almost, you know there is a lot of little stuff but it is all doable and been done by many here, including me feel free to pM me if you need help!

 

[bronco-billy-66]

As far as milage. I don't drive the LP bronco on the road at all. But I can tell you it burns about a bottle a day off road (8 gallon) depending how u drive . For comparison. My Efi bronco burns about 5-6 gallons a day on the trail.
I have 3 bottles. Two 8's and one 10 gal. I carry 2 on the truck. The gauges on the bottle suck I can tell u that Fo sho

 

[77broncodriver]

My fuel pump is only like 12 psi for tbi, if I go efi I'll send you a pm

 

[Nightstick]

My suggestion is to call Holley and have them help you tweak the projection system. The pane is awesome, but it has it's limitations.

 

[OX1]

My suggestion is to call Holley and have them help you tweak the projection system. The pane is awesome, but it has it's limitations.

If it is the 2D, I would not bother. I tried a used 2D (early not digital) and two brand new digital 2D's and never got any of them to work correctly.

 

[bmc69]

If it is the 2D, I would not bother. I tried a used 2D (early not digital) and two brand new digital 2D's and never got any of them to work correctly.

That. I'm a big fan of Holley Commander systems but have little use at all for those Projection packages.

My .02.