I'm pretty sure it is stock from the factory but not 100% on when ford switched over. I had a 86 with a 351 and it was carbed. I think it was the next year or two as i also had a 88 with a 302 and it was fuel injected. Back to the carb though, on trucks back then i had very few issues, yes i eventually took them off and did a clean/rebuild on them but then they were foolproof for a long time after setup. The 90's fuel injection is totally foolproof though i get what you are saying there. The biggest problem is it is attached to the whole computer system and associated smog garbage on these trucks that take time to figure out what is going on and what to replace. This forum here and a number of members who have incredible knowledge of these systems are invaluable. Before the internet it was a crapshoot to find a mechanic to solve issues like that.

Keep in mind this is an 8 year old thread...

EFI to Carb conv..
 

Doing the same thing to my 94 EFI because my 84 block cracked..Thank you, I was wondering about the fuel delivery ..

You’re taking the EFI parts off of a ‘94 engine to put it in the ‘84? Sorry just trying to figure out what you’re saying.

I can certainly answer the question as to "why" somebody would want to swap their EFI to a carb. It's because our EFI computers are getting old, no matter where you look (junkyard, eBay, etc.). These old computers start exhibiting very strange behaviors due to cracked solder joints, dry/burst electrolytic capacitors and so on. To go even further, our sensors that support the EFI system are getting old, and the aftermarket replacements are hardly worth exploring, let alone putting on the engine. They are just really junky. So when your computer is going bad with no new replacements (other than spending enough money to buy yourself a new truck), along with worn out or cheaply built sensors that give faulty information, carbs start sounding like a real good alternative. EFI is great, but when the parts to maintain that system just aren't there or any good, the EFI is just as unreliable or worse than the carburetor...

Having owned a couple of these now and unable to diagnose their "possessed" behavior, I now agree. On the other hand, I still don't think you should throw up the white flag and resort to a carb at the first sign of trouble unless your EFI system is truly cursed.

all well and good, until you try doing swap with truck having E4OD

I have both EFI and carbureted trucks. My biggest problem is remembering which one I am in and do I need to pump the gas or not. HaHa!
I will say my plow/yard truck, 89 5.0 has EFI and it sits the majority of the time. But it sure starts nice when I need it.

Well put Loud. EFI is wonderful when it works. Primitive 30-year-old EFI with mystery gremlins and limited parts availability is not. My dad's '87 has a carburetor or two in its future.

Is it possible to add a EFI to a originally carbureted motor? I’m trying to figure out why my 89 F150 jumps up to 3g after warming up and only idles back down after shifting into gear. Plus the previous owner did a cam job on it. Would that have anything to do with it?

There is no difference in the basic block/heads for a carb'ed versus EFI small block in this era truck.


Best guess is a vacuum leak perhaps.


It could be a contributor to your idle issue.The Speed Density EFI setup requires at least 114 LSA to work properly in most scenarios. Lumpy cams typically result in poor performance and stalling. Rare I have seen one cause a high idle.

Main difference is EFI blocks don’t have provision for mechanical pump.

needs for the conversion
 

Yes you will need a Distributor but not a new ignition unless for some reason it was 'chipped'.

While you can use the two internal low pressure and external high pressure fuel pumps, I find they are more to fail and the fuel return setup can be problematic, it might be better to drop the tank(s) remove the pumps and replace them with fuel line to the in tank filter then replace the high pressure pump with a new Carburetor low pressure 'Fuel Pump', but be sure to wire the fuel pump through the inertia power relay in case of accident.

Personally I use C6 or Manual Transmissions and I remove the computer and disassemble the wiring harness to make it cleaner and less of a headache to use, as well the open ports are perfect for running wiring for extra lights, or any 'gear' I need wired.

Take your time, use your phones camera and label everything!

I have a '95 F 150, 351 Windsor, E40D trans, speed sensor located on top of rear axle. First the speedometer went haywire, jumping all over the place. Then the engine started stumbling while driving and trans would upshift or downshift depending on which way the wind was blowing. Truck would stall when I put it in reverse. Everything I read pointed to speed sensor so I replaced that. Driving down the road 10 minutes later and it all starts happening again. More reading tells me that something in the speedometer cluster is sending a screwed up signal to the trans. Found another cluster in a salvage yard and changed that. Now the truck runs bad just like before and neither the speedometer or tach work. My plan is to go with a an Edelbrock 1406 because I have one, Edelbrock 2181 manifold that I paid $125 for in the original box that looks like new, fuel line regulator using the existing tank pumps, and replacing the E40D with a C6. Do all C6's have mechanical speedometers and what do I use for kick down linkage? I figure I'm going to have to put mechanical gauges in there anyway so I might be able to replace the entire speedometer cluster with one I build to fit the hole in the dash. I have a new factory stock distributor. Can I use that and the stock CD box or do I need something else? I know there are a lot of questions here but I only want to do this one time..