efi to carb...help
- Thread starter sdom001
- Start date
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yo guys;
Read thru this Swap Advice thread here in da Zone;
http://broncozone.com/topic/4173-efi-to-carb-conversion/
Synopsis:
BLADE262US
Youll have to run a 3 port regulator with a return in order to use your intank pump fuel pressure is way too high other wise . If you are going to dump the EFI then the only wires you need in that harness are the ones for the oil pressure gauge and the coolant temp gauge
Seabronco
You will also need to go to a simpler ignition system such as the Duraspark II ignition system used on mid 80's Broncos or one of the performance systems that are compatable.
The computer can also be trashed, since it will no longer have a purpose in life.
Like Blades said the EFI fuel pressure is too high for a carb, the fuel pressure for the carb should be around 7 psi.
Good luck,
There is a great site by a guy named Ron Morris. He deals specifically with conversions in either direction. If you don't see what you want on his site, you can contact him directly.
http://www.ronmorrisperformance.com/index.html
--
Elsewhere Justshootme84 advised
You need to address the fuel delivery system, since the EFI runs at much higher pressure than the carb. I switched to an electric fuel pump and pressure regualtor on my swap. Now would also be a good time to look into an HEI dizzy instead of the DuraSpark II you'll be swapping to, JSM84
Read thru this Swap Advice thread here in da Zone;
http://broncozone.com/topic/4173-efi-to-carb-conversion/
Synopsis:
BLADE262US
Youll have to run a 3 port regulator with a return in order to use your intank pump fuel pressure is way too high other wise . If you are going to dump the EFI then the only wires you need in that harness are the ones for the oil pressure gauge and the coolant temp gauge
Seabronco
You will also need to go to a simpler ignition system such as the Duraspark II ignition system used on mid 80's Broncos or one of the performance systems that are compatable.
The computer can also be trashed, since it will no longer have a purpose in life.
Like Blades said the EFI fuel pressure is too high for a carb, the fuel pressure for the carb should be around 7 psi.
Good luck,
There is a great site by a guy named Ron Morris. He deals specifically with conversions in either direction. If you don't see what you want on his site, you can contact him directly.
http://www.ronmorrisperformance.com/index.html
--
Elsewhere Justshootme84 advised
You need to address the fuel delivery system, since the EFI runs at much higher pressure than the carb. I switched to an electric fuel pump and pressure regualtor on my swap. Now would also be a good time to look into an HEI dizzy instead of the DuraSpark II you'll be swapping to, JSM84
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yo, I overwrote this;
EFI Swap to Carburetor; "...It's actually a pretty simple swap. Basically all of the computer/sensor stuff can be scrapped. You won't need any of it. What you will need...a carb (obviously), a new intake manifold, a new distributor, an ignition control box (like an MSD or Mallory box...I've had good luck with MSD 6A boxes so long as they're not exposed to significant heat), and a carb fuel pump. The EFI pump is way too strong for a carb so you'll need something like a Holley carb electric pump. The ignition stuff is pretty straight forward, but for a working tach you'll need to find the tach wire in the ignition wiring harness and attach it to the positive side of your coil. I know in Mustangs this wire was green with a yellow tracer. It may be the same in your Bronco, but it's good to double check. For a carb I would use something like a Holley 600cfm double pumper or a slightly smaller Carter carb. I had a 625cfm Carter on my Mustang before I switched over to a turbo'ed EFI setup and it was a little too much for the motor. One point worth stating is that if you have an automatic transmission that has overdrive (like an AOD), you'll need an adapter for the TV linkage on the transmission since AODs never came on carbed motors. One is (or at least used to be) available for Holley carbs through Sacramento Mustang, but they retail for just under $100. If you have a 3 speed like a C4 then all you'll need to do is make sure the carb has a kickdown linkage. Mind you I got my old Carter to work with my AOD...but I think that was just sheer luck. Hope this helps...let me know if there's anything else I can clear up for you..."
Source: by Steve at en.allexperts.com
&
http://broncozone.com/topic/12302-efi-to-carb/
EFI Swap to Carburetor; "...It's actually a pretty simple swap. Basically all of the computer/sensor stuff can be scrapped. You won't need any of it. What you will need...a carb (obviously), a new intake manifold, a new distributor, an ignition control box (like an MSD or Mallory box...I've had good luck with MSD 6A boxes so long as they're not exposed to significant heat), and a carb fuel pump. The EFI pump is way too strong for a carb so you'll need something like a Holley carb electric pump. The ignition stuff is pretty straight forward, but for a working tach you'll need to find the tach wire in the ignition wiring harness and attach it to the positive side of your coil. I know in Mustangs this wire was green with a yellow tracer. It may be the same in your Bronco, but it's good to double check. For a carb I would use something like a Holley 600cfm double pumper or a slightly smaller Carter carb. I had a 625cfm Carter on my Mustang before I switched over to a turbo'ed EFI setup and it was a little too much for the motor. One point worth stating is that if you have an automatic transmission that has overdrive (like an AOD), you'll need an adapter for the TV linkage on the transmission since AODs never came on carbed motors. One is (or at least used to be) available for Holley carbs through Sacramento Mustang, but they retail for just under $100. If you have a 3 speed like a C4 then all you'll need to do is make sure the carb has a kickdown linkage. Mind you I got my old Carter to work with my AOD...but I think that was just sheer luck. Hope this helps...let me know if there's anything else I can clear up for you..."
Source: by Steve at en.allexperts.com
&
http://broncozone.com/topic/12302-efi-to-carb/
yw,
But it is against ... never mind
Why bother to do all this stuff and still have potential probs w/sos Carb issues, esp in cold weather?
Is it for performance or having EFI issues?
The Efi fixes have to be ezier than getting the carb stuff in place and operating correctly.
But it is against ... never mind
Why bother to do all this stuff and still have potential probs w/sos Carb issues, esp in cold weather?
Is it for performance or having EFI issues?
The Efi fixes have to be ezier than getting the carb stuff in place and operating correctly.
Krafty
New member
on my 89 I went through 2 computers, 1 icm, a coil, and two separate motors that had bad tp sensors. and i only had that truck for one year. my 93 has no issues, its the luck of the draw. in the 89's case carb would have been easier. and as long as you can set your carb properly you won't have any cold weather issues. the next truck I buy is gonna be a restored 80 to 85.
Seabronc
New member
Well said Krafty
/emoticons/[email protected] 2x" width="20" height="20" /> . That is what I love about my 83.
yo Krafty,
I hear ya on all the EFI & EEC stuff that can and has caused you problems with the 89, but that was a bad doggy even before you swapped engines from a later year, if my memory is correct? A prev owner(s) prob never bothered with even the most basic maintenance, hence all the bad wiirng, cheap/junk yard sensors...
I was against sdom's intended swap (re my reply..."But it is against ... never mind) because it's illegal in most states and federal E laws.. and really, if someone needs to ask if it's possible/how to do it, well... ya know what's gonna happen after it's all plugged in... and the next Q is.. why can't I get above 12 MPG in 3rd?
EFI's to Carbs belong on the track is my advice (altho I'd love to get a new Ford block in there w/tri and cruise)
I hear ya on all the EFI & EEC stuff that can and has caused you problems with the 89, but that was a bad doggy even before you swapped engines from a later year, if my memory is correct? A prev owner(s) prob never bothered with even the most basic maintenance, hence all the bad wiirng, cheap/junk yard sensors...
I was against sdom's intended swap (re my reply..."But it is against ... never mind) because it's illegal in most states and federal E laws.. and really, if someone needs to ask if it's possible/how to do it, well... ya know what's gonna happen after it's all plugged in... and the next Q is.. why can't I get above 12 MPG in 3rd?
EFI's to Carbs belong on the track is my advice (altho I'd love to get a new Ford block in there w/tri and cruise)
Seabronc
New member
You do need to take into consideration what miesk5 is saying. If you can change the engine, but if you don't put in what was there it becomes an off road only vehicle. It is up to you to decide what to do with that.
Good luck,
>-
Good luck,
>-
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bobstrat
New member
Seabronc
New member
Hey!
Keep us updated with your progress. I'd suggest a photo log of everything you do. It will be a great story in years to come and may encourage other people with a similar interest, and those of us who aren't doing a modification of such a magnitude can just cheer you along the way./
Love a good adventure!!! :-B
Good Luck,
>-
Keep us updated with your progress. I'd suggest a photo log of everything you do. It will be a great story in years to come and may encourage other people with a similar interest, and those of us who aren't doing a modification of such a magnitude can just cheer you along the way.
/Love a good adventure!!! :-B
Good Luck,
>-
Last edited by a moderator:
