Alright guys rookie question here. I searched the forums but haven't found exact answers i need. I have a 1997 351W that's going into a 1990 F-150. Ive decided too convert too carb. Can y'all fill me in on 100% of everything i am going too need too do too convert from EFI too a carb? I wanna do away with all the wiring i can. Obviously ill need an intake and a carb. From what i have gathered ill need a fuel pressure regulator and a different distributor. Can ya guys give me specifics tho on what this is gonna take? And maybe some recommendations on a good carb that will be suitable for the 351? Thanks guys..

 

What transmisson do you intend to use?

 

I'm in the middle of a carb conversion myself and when the time comes my idea for the fuel setup is to create a return style setup with no more than the in tank pump putting fuel into the engine and to guarantee I have the exact pressure I need for a carb I'm going to use a ball valve on the return side and close it just enough so I can build 5 psi without over-fueling the carb or using an aftermarket pump of some kind. Now as far as stuff you need, you need something for a dizzy either it be a whole duraspark setup pulled from some other truck with the proper dizzy for your engine (let it be noted all duraspark boxes and wiring are the same you just need the right dizzy for your engine from what I know) or a standalone setup of some kind regardless if it be points or a one wire distributor setup that only needs key on power and vacuum and maybe a coil if you get a fancy one. Other than that you really don't need allot else other than the normal bolt on stuff for the engine and running all the vaccum lines.

I myself am going carb because I don't have the resources the time or the money to do a MAF setup and I know for a fact this engine is going to output way more than the stock SD setup ever could. That and this truck is a play toy/occasional work machine.

Sorry for the Slight highjack but I do hope my info helps any.

 

Shadow,
Do yourself a favor and get a proper return regulator.
there's no way you're going to do that with a ball valve or even a precision orifice.
Personally I would use Holley or QFT, and stay the hell away from any Prestolite owned company. (You know the ones I'm talking about)

As for ignition and simplicity I'd probably use a all in one HEI style distributor, run with 10Ga wire from a Bosch (type) relay.
There is no DSII wiring in the harness of a truck this late.

None of this will run with an E4OD, and I'm not sure of getting signal from the vss to the psom.
A U.S. Trans (née Baumann) controller is $800 or more with the sensors you need
A C6 or manual gearbox is probably the best bet.

 

Not trying to be a smart little turd head, but I have seen similar setups done before in the past, course the ones I seen were on farm cars and the way it was done was that the return pipe was smashed down enough to build some pressure but not so much the carb would over-fuel due to an excess in fuel pressure. That is what I have seen but it is still an untested theory but I can't see why it wouldn't work. I'm only wanting to debate a little for the OP's sake. Push comes to shove I buy one and try it, only 5 bucks for one after all as opposed to 50 for a regulator from summit.

 

I'm not trying to quarrel either. :/
Give it a shot.
I don't have any 'exclusive' on forum advice...

 

I'll be darn sure to post if it works or not, if it does then for once I had a good idea and if it don't well I can't say you didn't tell me so.

 

I always shake my head in amazement when someone proposes doing away with EFI for reasons of simplification, performance, or shortage of funds. Wrong on all counts, however, it's your truck.

Anyways, to be a little more helpful, I would not use any of the EFI fuel delivery components in a carburated system. The in tank pumps have to go, whether they are the low pressure lift pumps, or the later fuel delivery modules. Either replace the pumps themselves with a short hose, or source a couple of the tanks and pickups from a carbureted truck. Use the mechanical fuel pump on the engine. This may require replacing the timing cover and adding the eccentric to the cam. Not sure you can do that with the roller cam 5.8l/351W. Alternative would be an inline electric pump designed for the carbureted engine. A fuel pressure regulator may be a good idea, but you may need to plumb in a return line. 30 pounds or more pressure from an EFI pump is well above what you can run to your float bowl.

 

While EFI gives better mileage and performance, I wouldn't say it's simpler. There is simple EFI like our trucks have and then there's not-so-simple EFI like my buddy's 01 Lincoln LS that has a PWM fuel pump where you CANNOT get it to run except by the PCM's will. No jumping relays or anything. His PCM is being a PITA and not communicating with the PATS. No communication = no start. This cannot be fixed by anyone other than the stealership because a replacement PCM will have to be flashed. Not like our simple EFI where you can get a similar PCM, plug it in and go.

So, by some perspectives, a carb or mechanically injected diesel IS better. You might lose a MPG or two but you can work on it anywhere with basic hand tools and NO proprietary software whatsoever. I kinda like our generation of EFI and I'm keeping what's there on this truck for the foreseeable future, but I wouldn't mind putting an IDI and ZF with manual shift 1356 t-case and manual hubs into an OBS truck. That combo would give me the best body style with the simplest engine and drivetrain possible.

Also, some people just don't care to learn about EFI. They'd rather go with what they are already familiar with, which is cool as well. Automation and electronics have their place but some of us would like less of it, or none of it, on our vehicles. Same reason I replaced my electric shift transfer case with a manual one on my current truck, because I had the electronics fail on my previous truck and prevent me from putting my otherwise-perfectly-good transfer case into 4x4.

Just a different point of view...

 

I hear ya Dixie!


I'm no fan of some of the current trends, like monitoring your PCM for the insurance companies benefit and sometimes things become electronically controlled when there is no good reason to. I like the kachunk of pulling your transfer case into gear as opposed to twisting a switch or pressing a button. I also like getting out to manually lock up my hubs. Never did trust those automatic lockers. Sometimes things may even be arguably safer with a mechanical connection, like throttle by wire.

Just to put things into perspective, we were lucky enough to have a durable and reasonably simple EFI system with the EECIV starting in 1985. Our trucks are fully equipped to run EFI and the fuel system is not designed for carburetors. It becomes an expensive and difficult project to remove all the EFI components and replace them with carburetor friendly technology. A properly designed and tuned carbureted engine can run strong and so can the same engine when equipped with EFI. There are tuners available for the EECIV system and it actually becomes easier with OBDII technology, although now we are slipping into that area where you need more than a simple scan tool. There is some aftermarket support here and you can always go with MegaSquirt or F.A.S.T. If cost is a concern, check out some of the pricing on a new carb and manifold. Yikes!

Just another opinion, of course.

Edit;
This is a subject that has come up often. Of course, every time it does, somebody digs up an old thread and posts to it. Over 7 years old, but it has some remarkably good info and opinions.

https://www.ford-trucks.com/forums/8...arb-setup.html

 

Plenty of carbed trucks have in tank pumps...

The return lines and switch valves are already in this truck.
Plumb the regulator right to where the fpr came off the old rail.
If you get into swapping tanks, switch valves, harnesses, etc.. you're never going to be able to source repair parts down the road.

 

I would go with this setup
Holley 4150 4160 always gave me problems off road
New timing cover and fuel mechanical fuel pump it's not a chevy so it won't give you too much trouble
Points setup I've ran them for years they work fine for me duraspark if you're chicken

Also nobody has mentioned this and I assume you know but you will need a new intake

 

True. The 460 equipped trucks come to mind. However, there is a big difference between the carbureted pumps and the EFI pumps. I'm not sure of the year change, but the early in tank pumps were a lift pump capable of around 8 PSI with a frame mounted high pressure pump. Later trucks, and I think it was around '90, used a "fuel delivery module" which had an in tank pump that creates 40ish PSI

Yes they are and they rely on electrically switching the in tank pumps on or off as required. Fuel pump control is one of the problems you face when using the EFI pumps in a carbureted application. With EFI, they are controlled by the ECM. Delete this and you have to provide a switch to ground to control the fuel pumps. Hot side is from switched ignition, but you need something to shut off the fuel flow when the key is on, but the engine is not running. This becomes a safety issue. Also applies to any electric fuel pump. I have done this using an oil pressure switch and some creative relay interlocking.

OK, but you are working with high pressure fuel here. Not a job for rubber hose and clamps. Factory lines are nylon, you need compatible fittings and you need to ensure everything will still stand up to high pressure up to the regulator. I had a friend who did this on a high dollar hot rod. Tried regulating 60 lbs down to 5 lbs with a non return style regulator. Car had been built with a Holley EFI system, but he wanted to go old school with 3 deuces. ('32 Ford). Car ran like crap till he ditched the high pressure pump and put in an appropriately sized electric pump for a carbureted application. Also had multiple leaks and nearly burned the car down before he saw the light. This is where I fabricated that electric pump interlock I mentioned earlier.

If you put a carburetor where the parts guy is expecting EFI, you will have no end of trouble getting the correct parts. Bottom line is, you need to know what you are doing and how to ask for parts if you are going to try this on your own vehicle.

 

Yup 460's had "hot fuel handling"
In some years the oil pressure switch provided ground for the pulldown side of the fuel pump relay.
With a little 'creative relay wiring' it would be just as easy for this to provide a ground path in place of the missing ecu.
I understand the difference between a dead head and a return regulator, also the difference between a single reinforced rubber hose and worm clamp vs proper high pressure line and doubled constant tension clamps.

I too have witnessed atomized fuel under pressure feeding a fire.
It was not pretty and I am glad no one was killed.
You make it seem as if I'm suggesting/condoning/encouraging something reckless and dangerous.

 

Yeah fuel injection is nicer off-road when working with uneven terrain. I would not argue that. I was simply saying sometimes it's easier to go with mechanical stuff, for example with a carburetor you can drive thru water and never worry about getting your PCM wet. Ignition is another story but that's one area where mechanically injected diesels shine. All you have to worry about at that point is not ingesting water thru the intake.

I hear ya about the insurance companies and their data collection gadget that records everything your PCM can report. I told mine I don't want their spy device.

Could someone explain to me what Hot Fuel Handling is on the 460's? I've heard the term a few times but never did figure out what it actually meant.