Fuel Injection – Converting From Carburetor To EFI Or EFI To Carburetor (2024)

This subject has long been one of the most common technical questions we get asked here at LC Engineering on a daily basis. I am now going to attempt to cover this subject as comprehensively as possible. Because this can get confusing we will be talking about 1985 to 1995 22R/RE. On most pre 1985 engines the heads do not have all the intake stud locations drilled for the EFI manifold.

CARB. TO EFI:

So you're tired of stalling out on those gnarly hill climbs because your carb just isn't cutting it. So lets switch to fuel injection. Now you have some decisions to make. You can get a "donor" truck from a buddy or the junkyard and swap all the components from the factory fuel injected truck over to your carbureted truck. Now you need to make sure that you use 1 truck as a donor because many components are not interchangeable between different years. If you start to grab different components from different trucks there is a very good chance that you will have complications down the road, the last thing you want to do is go through all this trouble and find that you have mismatched components and now you need to start all over. Make sure that you get the whole engine harness from the "donor truck" including the ECU (Basically take every piece of wiring attached to the ECU), then get all the vacuum lines, switches, MAF sensor, solenoids, sensors etc If you do not get all of these components your truck may never run again. You will also need to run the factory EFI distributor and igniter. Don't forget to get the high pressure fuel pump from the "donor" truck too. Now the fun part is installing all this into your truck, HAVE FUN!

Now another option is to start fresh. LC Engineering offers all the components you need to convert without ever having to deal with the hassle of swapping out old used components plus we can add performance while you do the conversion. The main components needed will be; Big Bore Throttle Body, Ported & Flow Matched Intake Manifold, Hi Pressure Fuel Pump, Injectors, Fuel Rail, Fuel Pressure Regulator and an LC Pro Fuel Injection Kit. Now the most common Pro Fuel Injection Kit is Kit #3. The reason being is that it is a completely comprehensive kit that will control fuel and ignition and requires no other ignition components. Kit #2 does fuel and ignition as well but requires the use of an aftermarket ignition system (Crane, MSD, D.U.I. etc) and any distributor. Kit #1 controls fuel only and requires the use of a carbureted ignition system (stock carbureted distributor and igniter or D.U.I. distributor or LC Pro Distributor with a stock igniter or aftermarket ignition box). These LC Pro Fuel Injection Kits will completely take the place of a stock ECU and harness set-up so not only will you be able to add more horsepower but clean up your engine compartment as well. I said this could get confusing!!

EFI TO CARB:

Now that we got the hard one out of the way let's go the other way. For those of you who want to convert from fuel injection to a carbureted application here goes. First start by removing the factory ECU, harness, sensors vacuum lines etc The main components you will need for this conversion will be a manifold, carburetor or carburetors. For the ignition system you can run a D.U.I. distributor the LC Pro distributor with an aftermarket ignition box or a stock igniter. You can also run a stock Carbureted distributor with either a stock ignition or after market ignition. Due to the fact that the E.F.I. distributor has no advance you will need the above distributor when switching to a carburetor. You will also need a new fuel delivery system (you can just install a pressure regulator or you can get a new low pressure pump). This is basically all you need to convert your factory fuel injection to carburetion.

FINAL THOUGHTS:

Well if you are completely confused then my job here is done! I know that some of this information can get confusing, believe it or not I tried to keep it as simple as possible while still getting all the main information. All of this information is to be used as a basic reference of what you will need for either of these conversions, inherently there will always be small items that you may need such as gaskets, hardware and maybe even some minor modification/fabrication work. Remember you can always call in to LC Engineering for technical assistance as needed but now at least you have a rough idea of where to start.