Whats involved swapping FI engine into carb car???

DR1553

True Classic
I have a line on a 1979 carbed version with the engine and transmission already out. I own a 1987 that runs and shifts great, but the body is rusty. Both lower corners of the windshield frame and across the top are gone, rust on the doors and behind the rear wheels. Interior trash, brakes junk, steering rack junk, upper shock mounts toast....the list goes on

The 1979 body is in MUCH MUCH better condition than mine. Engine was pulled due to various problems and owner wanted to do a full rebuild, just never got around to it.

My question is what all is involved swapping my 87 engine and gearbox into the 79?

Being that I have a running and kinda driving complete 1987 I imagine I have everything I need.

I'm thinking differences are fuel tank, electric fuel pump and lines to fuel rail and return back to tank. Ignition parts, box in passenger compartment behind seat, everything else on engine or in engine compartment? Is anything under the dash different, will I need to swap the entire wiring harness?

What else am I not thinking of? Is this worth doing?
 
You have the basics covered. Since this was already a 1500, you should have the proper gas pedal, accel cable and linkage. If you had a 78 or older, your task would be greater. I learned that the hard way. :)

Since you have the 87 on hand, you can just mimic the location of the various bits into the 79. My thread on the 78 project is here. There is a post on cutting the hole for the FI harness that you might find helpful here. There are some pics in there where I mount the fuel pump and the FI controller, so maybe those would be of interest too.
 
I read thru your thread, been almost 4yrs since you updated it...did you get it done?

I'm hoping since the 1979 already had a 1500 it won't be near the trouble you went thru. But that's why I'm asking, to find out just how big of a project this will be. I'm hoping this won't be too terribly much more than a regular engine swap.
 
DR1553, I will be doing the same as some point for pretty much the same reasons; in my case a very rusty '85 into a very solid '79. My '79 actually has a decent engine/trans, but I am planning a turbo project so the FI engine is much better suited. What I haven't decided is if I want to swap the whole engine or just the head and related components (the '85 has a 10 bolt head that would need the holes enlarged). I'll have to do some tear down to inspect both to see which has the better bottom end to work with.

Your '79 would have been a 1500. The most difficult aspect might be the wiring I'm guessing. Otherwise it seems to be pretty much a 'bolt-on' affair. Please keep this thread updated with what you learn.

Thanks Jim, I'll review your links for more info.
 
I read thru your thread, been almost 4yrs since you updated it...did you get it done?

I'm hoping since the 1979 already had a 1500 it won't be near the trouble you went thru. But that's why I'm asking, to find out just how big of a project this will be. I'm hoping this won't be too terribly much more than a regular engine swap.

Nope. Never finished it. I am a bad boy. It is sitting in the corner of the garage waiting for me. It mocks me every time I go in there. :(
 
The "box" in the spare tire compartment is the fi computer. You will also need the double relay that is bolted there, just in the middle of the car.

As long as you will have the 1987 engine on the ground, it may be a good idea to split the transmission to change the clutch. It is so much easier when it's on the floor.
 
I've converted lots of Fiats and Lancias to fuel injection. Your conversion couldn't get much simpler. You already have all the difficult parts in place: control arms, hubs, axles, shifter. The FI has a separate harness connected to the car by the dual relay located near the ECU. There's only about four wires to connect. Everything else is as simple as removing from one car and installing on the other. I did a '79 Spider over a weekend. Worth doing? Absolutely!

I have a line on a 1979 carbed version with the engine and transmission already out. I own a 1987 that runs and shifts great, but the body is rusty. Both lower corners of the windshield frame and across the top are gone, rust on the doors and behind the rear wheels. Interior trash, brakes junk, steering rack junk, upper shock mounts toast....the list goes on

The 1979 body is in MUCH MUCH better condition than mine. Engine was pulled due to various problems and owner wanted to do a full rebuild, just never got around to it.

My question is what all is involved swapping my 87 engine and gearbox into the 79?

Being that I have a running and kinda driving complete 1987 I imagine I have everything I need.

I'm thinking differences are fuel tank, electric fuel pump and lines to fuel rail and return back to tank. Ignition parts, box in passenger compartment behind seat, everything else on engine or in engine compartment? Is anything under the dash different, will I need to swap the entire wiring harness?

What else am I not thinking of? Is this worth doing?
 
The FI has a separate harness connected to the car by the dual relay located near the ECU. There's only about four wires to connect.
Perhaps you could do a little write-up with photos of the wire harness swap? I would appreciate seeing it prior to jumping in on my conversion. Thanks.
 
I have a line on a 1979 carbed version with the engine and transmission already out. I own a 1987 that runs and shifts great, but the body is rusty. Both lower corners of the windshield frame and across the top are gone, rust on the doors and behind the rear wheels. Interior trash, brakes junk, steering rack junk, upper shock mounts toast....the list goes on

The 1979 body is in MUCH MUCH better condition than mine. Engine was pulled due to various problems and owner wanted to do a full rebuild, just never got around to it.

My question is what all is involved swapping my 87 engine and gearbox into the 79?

Being that I have a running and kinda driving complete 1987 I imagine I have everything I need.

I'm thinking differences are fuel tank, electric fuel pump and lines to fuel rail and return back to tank. Ignition parts, box in passenger compartment behind seat, everything else on engine or in engine compartment? Is anything under the dash different, will I need to swap the entire wiring harness?

What else am I not thinking of? Is this worth doing?
I did a fuel injection conversion on my '79 and it was not that difficult. You have it made because you already have all of the parts. The fuel injection harness is separate from the rest of the wiring harness. You should get the '79-81 wiring diagram book as it has both the '79 carb version wiring harness diagrams as well as the fuel injection wiring of the '80-81s. That way you can compare them to figure out how to pull power for the various fuel injection unique parts. MWB sells it.

There are some minor problems that you will need to solve. One, how to mount the fuel pump as there are no threaded holes in the location where the fuel injected models have them. Two, the bracket with the spare tire hold down bolt is different on the carb versions, so if you plan to put the computer behind the spare tire, you will need to decide how to do it. The spare tire on the carb versions is put in with the outside facing the firewall, whereas the fuel injected cars have the outside of the tire facing forward. I ended up taking the computer off of its frame and mounting it directly to the firewall, that way it still fit under the bracket and I could still put the spare tire in. You will have to cut the hole in the firewall for the harness.

One cool thing is that the bracket that holds the fuel filter for the fuel injection mounts right to the same bolts next to the fuel filler neck that hold the blower fan for the carburetor on the '79. The bracket that holes the air flow meter is almost a direct bolt on to the same angled bracket that supports the fan motor. Unfortunately, the mounting bolts are shorter than they are on the fuel injected versions. I cut off the bolts, drilled them out and then epoxied longer ones up through the holes to attach the AFM. The air cleaner also attaches to one bolt near the fuel filter but I had to drill and tap a hole for the other attachment point on that angled firewall bracket.

You will have to figure how to mount the fuel lines to the body of the car. There are no punch outs for the little plastic brackets that hold the supply and return fuel lines in the '87. Changing the fuel tank is pretty easy. One of the holding straps for the fuel tank of the '87 has an extra threaded bracket for attaching the fuel pump protection panel so be sure to swap that over. If you are able to mount the fuel pump on the '79 in exactly the same spot as the '87, then that panel will also attach to the fuel pump bracket.

If you want to add the blower fan in the trunk, there are a couple of snags here. First, the antenna is on the left side, instead of on the right, so it takes up space where the blower motor would normally sit. Plus, the mounting brackets that Fiat added for this blower motor are not there so you will need to come up with another way to hang the motor. I ended up angling the motor so it would clear the antenna, and then I drilled a hole behind the left light cluster and epoxied a nut there to add another attachment point for the motor. I can take some pictures of how I did these mods if you want. Make sure to take the access panel from the '87 as it has the blower channel built into it.

You mentioned changing the entire wiring harness. The fuse panel and wiring harness for the '87 is more modern and way different than the '79. I think it is much better, and it has all of the circuits and relays needed for the fuel injection system. But, all of the console switches and connections are different, the headlight switch is different, the wiper/turn signal switch connections are different. So if you want to swap in the '87 wiring harness, be prepared to change over a lot of other electrical pieces. There will be wiring for things that the '79 does not have, like courtesy lights in the doors, power windows, among others.

I realize that this was a bit long winded, but it is definitely doable, it will just take a little ingenuity.
 
No photos handy, but this is how the dual relay is wired to the car:

88d connects to the fuel pump positive terminal
88z is connected to the battery positive (always hot)
86a is connected to the ignition switch terminal 50 (hot when cranking)
88y ignition switch terminal 30 (always hot)
86c is connected to the ignition switch terminal 15 (hot when key is in the “on” (drive) position)

That’s as complicated as it gets.
 
Rodger is right about the fuse and relays box. The 1987 is much better and worth keeping but it involve changing a few things as he said, like the headlight switch. I remember the headlight switch hole is larger for the 1987 (or is it the reverse?). So you will end up enlarging the hole in the dash or modifying the harness plug to fit the early switch.
 
You guys may not like this but.....what if I just use my 87 engine and throw the 79 carb and intake on it? That will get me driving the quickest, then I can always do the FI conversion later next winter.

Fuel pump would be my question....79 would have mechanical pump....87 has electric. How do I get fuel delivered into the carb with an 87 engine?
 
There are lots of 1500 carbed engines running out there (all '79s), so it can work. You will get opposing views of a carb vs FI, but I think most would agree the FI is a much better running system (assuming it is working properly). However that's not to say the carb is bad (also assuming it is working properly). Both can be challenging to get "working properly", depending on your working experience/knowledge of either.

The carb intake manifold has different port shapes than the FI intake. The FI inlets include projections where the injectors mount. And the two heads are accordingly different. The carb head has round ports and the FI head has "reliefs" cut into them to match the injector locations on the manifold. So the gaskets for the two are different; be sure you can seal the carb manifold on the FI head.

The fuel pump can be replaced with a generic low-pressure electric unit, fitted inline between the tank and the carb. Inexpensive inline filters can be used (ideally two fuel filters, one on each side of the pump). The pumps can be found online at all price ranges. The Weber carb likes a very low pressure, around 3 psi.

When you convert to the FI, the fuel pump will need to be replaced again with a high pressure one.

Honestly if you are swapping engines, then I'm not sure it is that much less work to swap to the carb. Seems it would be about the same effort/time to just use the FI system. But that is a judgement call.
 
You guys may not like this but.....what if I just use my 87 engine and throw the 79 carb and intake on it? That will get me driving the quickest, then I can always do the FI conversion later next winter.

Fuel pump would be my question....79 would have mechanical pump....87 has electric. How do I get fuel delivered into the carb with an 87 engine?
You could transfer the mechanical fuel pump from the '79 to the '87 block, or you could use an electric fuel pump. What you absolutely can not do, is use the 87 FI fuel pump in a carburetor setup.
 
If you are pulling the EFI motor it makes more sense to leave it all attached & run the harnesses. Since nothing is integrated into the main body harness this is a simple install, which will likely take not much more time than swapping over all the carb stuff . The most “difficult “ part is selecting the wires to feed the Dual Relay.....
 
Honestly, the stock carb from the '79 was pretty weak. If you are used to driving the FI '87, you will probably be disappointed in the performance drop to the stock carb set-up. You can go with a bigger carb, dual carbs, performance cam, etc., but that doesn't sound like the direction you were heading towards. Yes, putting the carb set-up on will be quicker if your goal is to be out driving this summer. Shouldn't be much to it since the car was set-up that way. There was a ton of anti-pollution stuff on the '79's, but obviously that is not an issue with the FI motor.
 
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