5.0 CFI to SEFI Upgrade

Topic: 5.0 CFI to SEFI Upgrade (Read 24679 times) previous topic - next topic

5.0 CFI to SEFI Upgrade

July 13, 2013, 07:33:13 AM

do we have any threads floating around about converting an 85 5.0 to efi. I'd like to convert the Vert, and seeing I have many parts floating around for EfI, including computer and wiring harness, is it at all do-able?

5.0 CFI to SEFI Upgrade

Reply #1 – July 13, 2013, 08:56:16 AM

here is my theory,

use a 5.0L truck eec, injectors and your existing wire harness along with the trucks map sensor making it speed density , could do an ho cam i suppose.

"EFI" labled upper intakes or "FUEL INJECTED EFI" upper intakes all use the same fuel delivery eec architecture on your eec pins 58 and 59. all injectors on one side of the motor fire off at once then all 4 on the other side fire off.
this is the same as "CFI" essentially.

the 1988 Bird V6 was a one year only deal that saw a "Fuel Injected EFI" which fires just like CFI.

my point is you could use your existing harness if you went this route... gas mileage may not be so bad either,, just a theory.

with only like 89 of the verts made,, the 5.0L CFI trottle body found on a lot of early LTD's and such would really wake up your car,,,keeping it original somewhat.
I know the CFI stuff really well, that V6 just needs a little more air.

ive never heard of any of the verts havng anything other than the CFI V6 engines.

since you have the harness and such, its basically replicating what is under the hood of your formly white LS and repeat that over to the vert.

I am basically doing the same to my white LS which is idetnical to what yours was,, i just got a harness and have excess parts so this winter is my youngest boys build starting up.

5.0 CFI to SEFI Upgrade

Reply #2 – July 13, 2013, 04:16:12 PM

I have an 85 V8 CFI vert, 1 of 16 or so...it needs a lot of help to idle right now, I'd like to make it a little more user friendly. I already have upper and lower intake, injectors, computer, wiring harness, and a t-body all from my 87 parts bird,think all I would need is a fuel rail.... I believe I have the nylon lines to run to the tank too, my real question is, is it doable on the 85 V8? or am I going to run into problems trying to do this?

5.0 CFI to SEFI Upgrade

Reply #3 – July 13, 2013, 04:19:17 PM

or should I just upgrade the CFI I have now like Jcassity said? I dont know what direction I should go to remedy the old tired parts that will need to be replaced

5.0 CFI to SEFI Upgrade

Reply #4 – July 13, 2013, 05:25:25 PM

CFI has one unheated O2 sensor. EEC Pin 29
SEFI has two heated O2 sensors. EEC Pin 29 Right side and EEC Pin 43 Left side.

CFI has an EGR Control Solenoid, EEC Pin 52, and a EGR Vent Solenoid , EEC Pin 33.
SEFI has an EGR Vacuum Regulator Solenoid. EEC pin 33.

CFI has Throttle kicker solenoid. EEC pin 53.
SEFI has an Idle speed control solenoid. EEC Pin 21

CFI has a Manifold charge temperature sensor. EEC Pin 25
SEFI has an AIR charge temperature sensor. EEC pin 25

CFI has an exhaust heat control solenoid. EEC Pin 35
SEFI has nothing equivalent.

Is the '85 battery on the passenger side?

Does SEFI require a different distributor?

5.0 CFI to SEFI Upgrade

Reply #5 – July 13, 2013, 05:31:46 PM

yes the battery is on the Passenger side...
No idea if the distributer is different

5.0 CFI to SEFI Upgrade

Reply #6 – July 13, 2013, 06:16:19 PM

Auto Zone shows different part numbers for 85 and 87 distributors.
Moving the battery may be the biggest pain.

5.0 CFI to SEFI Upgrade

Reply #7 – July 13, 2013, 06:39:17 PM

changing the battery over wasn't to bad in my 87 3.8

5.0 CFI to SEFI Upgrade

Reply #8 – July 13, 2013, 08:22:03 PM

damiac, when you went from cfi to the 5.0 on your black car, you essentially did a sefi swap. you've already done a cfi to sefi swap.

5.0 CFI to SEFI Upgrade

Reply #9 – July 13, 2013, 08:30:40 PM

so in a nutshell.. I can just bolt all the stuff to the engine that I need to make it Sefi? even being an older block with E5 heads? what about the distributer being a diff part #?
is it because the lower intake is diff? I'd hate to get half way through and it's not going to work.

5.0 CFI to SEFI Upgrade

Reply #10 – July 13, 2013, 10:16:48 PM

cfi uses a duraspark ignition system. the newer tfi system is more standard of an ignition system. I'm sure you could keep the old distributor and ignition, but I would upgrade to tfi if it were me.

everything should bolt up fine. the old heads are better then e6 heads and are very similar to e7's.

5.0 CFI to SEFI Upgrade

Reply #11 – July 14, 2013, 01:16:50 AM

Quote from: Haystack;418585

cfi uses a duraspark ignition system. the newer tfi system is more standard of an ignition system. I'm sure you could keep the old distributor and ignition, but I would upgrade to tfi if it were me.

everything should bolt up fine. the old heads are better then e6 heads and are very similar to e7's.

nope,, and yes,, the yes part applies to one year only.
his CFI uses the TFI/stator as we do.. all the same. the pn difference is the height of the shank on the dizzy of the 3.8 compared to the 5.0.
if your gonna go 5.0 in there, will all come together anyway so the dizzy thing is moot.

yes you can just dump all the SEFI stuff you want in there and still run the same heads.
, it will all come together basically likey your LS did.

good call by softtouch for engine bay stuff, the LS 3.8L CFI's i am 99% sure all had thier battery on the passanger side,,

if you think your parts compatibility is going to benefit you in the long run (thats what i would be thinking) then yes migrate away from CFI. Add larger TB but keep the Green top injectors (minus the injector screen) and that will be a night and day difference in the cars response and power. THis would be the most transpartent change and keeping all visually original.
Your CFI fuel pres regulator is adjustable as well incase you didnt know, there a plug on the top,, drill and pop it out and there resides the allen screw. if its a plastic plug on top, its aftermarket.
IIRC,, one complete rotation clockwise is about 3psi increase

interestingly enough,, CFI chassis car is itching to have its **********************REAR PASS******* fuel lines grafted into the fuel rail of a ford explorer fuel rail system,,,, HINT HINT,,, not so on the oem set up on the fox 5.0~~!! so you will be in good shap if you use your inginuity you may be the first to integrate oem explorer fuel rails to your ready and waiting fuel lines ***with*** a cleaner fuel supply line system in the rear.
i was just talking about this a couple days ago with 86tbird down in FL.

5.0 CFI to SEFI Upgrade

Reply #12 – July 14, 2013, 01:28:07 AM

The 85 CFI does use the EEC IV TFI ignition.
I believe the SEFI distributor PIP has one pulse a different width than the rest to designate cylinder #1. So it also serves as a crankcase position sensor. This is so the EEC can synchronize the injectors with the cylinder that has its' intake valve open.

5.0 CFI to SEFI Upgrade

Reply #13 – July 14, 2013, 07:52:12 AM

this is interesting, because I just happen to only need a fuel rail and a larger T-body to make this happen....... and probably the distributer. I dont think I have an extra for a SEFI .

tell me more about this explorer rail, and what are green top injectors?

5.0 CFI to SEFI Upgrade

Reply #14 – July 14, 2013, 11:09:52 AM

the exporer fuel rails source and return both dump down along the rear of the engine,, thats a perfect match to "about" where your screw on CFI lines stop.

the fox body sefi fuel rails all come in up front on the pass side engine bay,,
what im saying is that your car/chassis design is compatable with the explorer fuel rail design ~less the connectivity and figuring that out.

your green top injectors you have now (thats what you should have) are 34lb / hr high resistance.
The 5.0CFI came with blue top 54lb high resistance injectors and a much larger air tunnel ports and trottle plates.
simply install your green top injectors into the 5.0 CFI and you move more air. you will notice that the v6 cfi air tunnel ports dont match the much larger EGR spacer plate.
The 5.0 CFI air tunnel matches up perfectly.

The CFI splits in half via 4 phillups screws from the bottom... basically the 5.0 lower half cfi has the larger air tunnes as compared to your v6 CFI lower half.
i highly recommend a speed handle and an apex tip phillups bit,, these screws are a to get out due to they corrode.

one good and basic reason for lack of power right off the top of my head is...........
--- remove cfi 4 nuts and linkages ect
---the rear gold looking drivers side vac line fitting will likely be carbon clogged once you flip the cfi over and see the problem, chip away all the stuff that doesnt belong.

---the hesitation you feel when flooring the gas is a gas flow problem.
---remove the injector screens and vula, no more hesitation... i and others chased this issue down for months and most of us having no codes or no problems with our engines,, of course im on a very small team of people who tried it and liked it. shiznit can the screens, they are a restriction for the small motor,, thats what your fuel filter is for.