Hello big Bronco Brethren. I'm going to upgrade the fuel system on my 78 Bronco, and need some help/advice on my plan. I want to fix the occasional vapor lock problem, and prepare for fuel injection in the future. I plan install a 85/86 33 gallon tank with the in tank pump. It should bolt right in. I will need to change the filler neck also. The skid plate is interchangeable. Of course I'll need modify the fuel lines with a return line, and use a regulator to get the fuel pressure down at the carb. I plan to use the 85/86 fuel pump and sending unit. Thoughts and advice please. Oh and I've decided against using a frame mounted electric pump for a number of reasons.

Thanks

 

I don't have any input, but I'm interested in the replies. I've been considering doing similar to mine in prep for a sniper type efi install. It seems like the electric pump and regulator/return would be more consistent for running the carb until the upgrade too.

 

I've looked at this from several different approaches, but going with factory parts seems to make the most sense. The 86/89 fuelies used a combination low pressure in tank pump and a frame mounted high pressure pump, the later models a high pressure in tank pump. I've can get all the pieces I need for either system at Bronco Graveyard. I need to decide on 90-95 in tank, or 86/89 hybrid system.

 

A little update. So it turns out I don't need to replace my current tank. The earlier fuelie Bronc's (86/89) used the same tank with 2 inch hole for the sending unit/fuel pump. Also the earlier trucks had a "low Pressure" in tank pump (15-17psi), and also a high pressure frame mounted pusher pump. One the reasons I didn't want the frame mounted pump is because it's been my experience that they don't perform well or last because they tend to run hot starved of fuel. With this set up that won't be an issue. My plan is to set it up initially with just a bypass regulator and a return line with the carb. Later when I upgrade to fuel injection I'll install the frame mounted high pressure pump. BTW these guys make a port injection system for the 351M/400 https://460efiguys.com/351m-400/. I've ordered all the pieces, and will post pictures once the work begins.

 

If you're running a 335 engine go talk to Russel at 460EFIGuys before you buy the Sniper.

 

I hear you. The problem is their kits cost 2x as much. It looks like a better way to do it, but the Sniper is already too expensive. The other advantage of the Sniper is it should be reusable if I move from the 400 to a 460 later. I'm mainly looking at FI because I would like automatic temperature and elevation adjustment, since living in the Rocky Mountains, 140 degree yearly temperature swings and 7,000 daily elevation changes are possible.

 

Had vapor lock issues with my wife's Bronco too. Had re-routed the fuel pump to carb line with a rubber hose away from the block and heads. I also insulated the fuel line coming out of the tank above the rear axle as the exhaust was within a few inches of the line. The latter seemed to fix the issue.

 

Somewhere around here there's a TSB from the the 1970's, and the fix from ford was to install a in tank fuel pump, regulator, and a return line. I believe some of the carbureted big block trucks actually had the system installed from the factory. My problem shows up on hot days after a run on the freeway and then slowing down in traffic.

 

Well looks like I'm going to have to replace my fuel tank. Once I got it off the truck and started to clean it up I discovered some pitting. pictures tomorrow.

 

33 gallon old sending unit and new sending unit with pump and return line. both 2" diameter mounting

New plastic 33 gallon tank with sending unit/pump installed.

 

Plumbing is all done, just need to do the electrical

The new tank is in.
Works almost done. The last step is to wire up the fuel pump controller. I went with Revolution Electronics, it has an automatic 3 second priming feature. It's been triple digits here for the last couple of days, to hot work out there! The forecast is 104 today!

 

All done now. Everything works as expected. Now for some road testing.

Pressure steady at 5psi

 

Looking good!

I was going to suggest you go with just the in-tank pump from the 85/86 setup since it's low pressure, but then read you were already going to do that. Good call.
I have an '85 Bronco that was originally an EFI 302. I installed my 300 I6 into it with a Holley Sniper kit. It works great.

If I recall from my research, the in tank pump is only about 5 - 7 psi, so you may not even need a regulator.

 

Thanks, I'm real happy with it so far. We've had triple digit weather here in socal the last couple of weeks and it's stressed the system pretty good. It's starts way better cold or hot. Ultimately I want go with a port injection system. I may go ahead and add the frame mounted high pressure pump anyway. It's the best upgrade any of the 73-79 trucks and Bronco's. I don't understand why Ford only put FI on the 302 engines in 85/86.

 

I'm thinking that it's because of the Mustang. Their flagship Mustang shared the 302 with the trucks, so it was the first to get EFI.
Then, in '87, their workhorse/fuel mileage 300 I6 got EFI.
Lastly, the 351w to finish it off in '88,