4.0 Carburetor Conversion

terryjm1

Well-known member
Jan 23, 2011
1,496
381
FWIW, as others have stated, it is relatively very simple to convert an EFI 4.0 to carbs and a distributor or carbs and EDIS. Personally, I wouldnt go with carbs unless I was just desperate to make it run and had a setup laying around that would cost me no more than new gaskets.

Us Triumph TR8 people have for a very long time been taking 4.0 and 4.6 Rover engines and slapping on carbs and distributors from our old 3.5 engines.

That being said, it is for ease, convenience, and is cheap. I very much prefer EFI and have adapted GM TBI and multiport 90’s era injection systems to my old TR8s. The TBI is a sort of Frankenstein but wow is it simple, reliable, fuel efficient, and cheap. Parts are in stock at Autozone, cheap. The multiport is more elegant but was a lot more work. Both are significantly simpler and more cost efficient than the factory Rover stuff. That being said, I cant imagine I would remove the factory stuff on a Discovery for either system.

For me EFI is the way to go but some prefer the simple approach. Who am I to judge? To each his own. I took out the 4.0 EFI automatic in my D1 and replaced it with a 300TDI and 5 speed. I completely elimated the electronic aspects in the process. Diesel fuel and a strong battery and it runs flawlessly. (My D1 lives in a metal Quonset hut sheltered from possible EMP effects on the side of mountain... not joking but a total coincidence. :)) Considering advanced technology alone, that is a downgrade. However, I consider my old tech diesel and manual gearbox far superior.

I know there is often rude commentary here but it is nothing compared Defender Source. I own a “bastard” Santana and that alone is considered sacrilege to those folks. “What idiot would buy a Santana when they can buy a Defender in like condition for 4 times the cost???!!!” For those of you not familiar with the Land Rover Santana's, they use about 95% Land Rover parts, were assembled in Spain, and later model ones (until the late 80s’s) look like Defenders. Earlier models are near identical to Series models of the same era but have galvanized chassis. Why would anyone buy one of those??!! (Yes, sarcasm.)

Note my comments are not angry or rude. It isn’t that hard... be happy!
 
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Leadvagas

Well-known member
Jun 10, 2010
232
2
Leadville CO
Looking to convert from EFI to a carburetor on my Disco I, 4.0 engine.


It has electronic ignition. The plan is to also swap that out to a distributor and coil.


My question is this:


Electronic ignition is currently working fine. Can the EFI be converted to carburetion while still using the electronic ignition until funds are available to also swap out the ignition components, or are the EFI and electronic ignition systems tied together in the onboard computer system?


I have read the threads on a swap done several years ago by the Canadian guy (MontrealRR something or other) on this forum , but he swapped out both fuel and ignition components (cam shaft, front plate, etc...) at the same time.


PM'd him some questions a few days ago, but doesn't look like he's active right now.


Thx![/QUOTE

Ok, So I will try and answer this a little bit more directly. First you will need quite a few parts. I might miss a few I live in the '95 world, but I have done a dizzy 14CUX 4.6 with good success. You will need the following
Engine front cover
oil pump
cam, not 100% sure but probably, GEMS may not have a cam gear
head set and head bolts
Dizzy
associated wiring, coil etc
Intake manifold
Carb of your choice
throttle linkage etc
Now that that you have the above parts list, probably about $1500 or so in parts, the real fun begins. You will get to figure out how much stuff on the truck doesn't work because you have abandoned the ECU. The real answer is, on a mostly modern EFI European car, the EFI touches just about every thing. Ask me how I know. So what the folks here are telling you is, take the $1500 to $2500 and the 40 plus hours it will take you to get anywhere close to done and use it to figure out the problem you have. Oh, and by the way, doing a conversion like that on a car delivered with EFI is a federal crime. Not that they tend to enforce such things regularly, but fyi.
 

JohnnoK

Well-known member
Mar 19, 2017
193
19
Cape Town, South Africa
There are a few guys on other forums that have carbed the 4.6 quite successfully, so it is doable.
It depends on how far you want to go with it, but unless you are putting the engine in an originally non-ECU car, it's a lot of bother trying to get around the peripheral ECU wired-in stuff and making the set-up think it's still running the ECU.