What would it take to go from EFi to Carb

[Mastiff Rider64]

Th EFI parts are all name brand and available. They are all very reliable.

There is truly no reason to change any of them other than the pump and the O2’s. They are in fact wide band, and clean everything else

No disrespect, but you need to find another Mechanic. There is too much guessing and throwing parts at it, without any proper diagnosis.

Did they even check the faults were?

They have check for faults and so have I. Sometimes the check engine light will be on, I can hook up laptop with protune and click to read faults and none will come up. But the when I turn the key off and back on the engine light is off.

 

[No H2O]

Sorry but its a terrible idea.

Understand you’re frustrated, but EFI is superior in every conceivable way.

I couldn't agree more, I'd fix the EFI you're still ahead $wise than converting to carb and you'd have the benefits of EFI

 

[mleach72]

So I did some research on this subject, and it appears to be a fairly simple swap. I'm not suggesting that you swap the EFI for a carb, I just want to give you all the information from what I have gathered. The ech's are basically identical. The efi version just uses empty circuits on the carb version. I cross referenced the ehc on both systems. All non-efi circuits are identical. The only difference I can find is the carb version has a ground for the ignition module. The efi version does not. It shouldn't be hard to tap into the harness to connect the ground. The only thing I'm not sure of is the connections going to the ecu/vfi that will now be used for the ignition module. At best, it might be plug-and-play. At worst, you would need to look at the schematic and install the correct jst connectors. Basically, it comes down to removing the efi ech and installing the carb ech and hooking up the ignition module. Then plug your harnesses into the new ech. The engine sensors and o2 sensors can be left where they are. They will be "dead". Then it's just a matter of removing the TB and installing a manifold, carb, and petcock. I figure about $1000-1200.

Carb ech from Curtis-$550

New G carb or Mikuni-$350ish. IMO, the mikuni is going to mimic efi better.

S&S manifold-$125 or so.

TH ignition module-$229 OR I can send you a stock module no charge.

The good thing is that you should be able to change back to efi if you want.

 

[Sven]

EFI Basics:
1. Wire out of connector.
2. Connector not connected.
3. Signal out of range, short, or open.

So key on sets a code, key off clears the code, key back on shows no code light = Phantom Glitch.
The can't be's:
A wire out, nor disconnected, nor out of range, nor short, or open. Get it? Has to be the software cycling via key goes to ground when off, meaning open at the key disconnect.

Component [sensor] has to flat out fail or be out of range. Can't be out of range and clears. Has to hold that code light on is now a hard set or code. If the black box needs just a ground, the unplugs still land on the basics of 1, 2, and 3, meaning, it's 1-2) not connected, and 3) out of range or open. You just set off the christmas lights on the dash.

Simple charging loop is battey/VR/stator. Simple ign loop is, crank signal or cone timing plate/carb/spark box./aka - Dyna.
Covert FI from carb: Crank sensor [cone]/VOES/02 sensor/TPS/Temp sensor [head heat/or air temp at the intake somewhere/ECU, injectors.
3 components vs. 7 plus to set the spark/fuel the mix.

Signed,
Pro Both Setups. One you play in the sandbox and have that level of skill; the other is college material heading toward a Pee Hate Disshit.