Hell all I have a 92 940 gl and was wondering if anyone knew anything about converting from fuel injection to carburetor. Im much better with a carb.

 

You can do it, but you'll lose gas mileage and performance. You'll need everything from a pre78 volvo 240. ANd Pull your complete system that is currently in the car out. Replace with the less reliable carb system and, enjoy?

The FI system is dead easy on these cars, and a ton more reliable. If you can rebuild a carb you can take 2 days to learn how an FI system works.

 

I agree that the fuel injection systems on these old Volvos are remarkably simple and reliable. Unless you've got some aftermarket conversion kit you're better off with the fuel injection than the SU carbs the older models came with.

 

Go to www.stepbystepvolvo.com for free guide to 740 no-starts. That has a couple of links to wiring diagrams for fuel injection systems.

 

Yes I have an 86 240 sedan. Just bought it. Whole FI sys is shot. I'm thinking of going carburetor. Easier to work with. No electrical bull. I say go for it.

 

what does 'whole FI is shot' mean, anyways? bad wiring harness? LH 2.2 is incredibly simple as EFI goes.

indeed, you'll lose at least 2 of the triad {horsepower, low end torque, fuel efficiency}.

you'll need to replace the intake manifold with one that fits carbs (oh, B23/B230 engines NEVER had carbs in the USA, so you'll need to find a manifold overseas, or maybe a marine application). you better remove the cat, as you'll foul it with rich running carberuetion. the high pressure fuel pump will need to be removed and bypassed (the in-tank transfer pump will likely suffice). you'll need to replace the ignition system, as the EZK ICU gets input from the EFI ECU that it uses to calculate timing advance. you'll robably need to rig up a choke for cold starting. your car will never pass any sort of smog inspection, we'll assume you don't have that in your state/country.

 

Yeah you're right it's a lot more involved than ripping the manifold off and slapping a penta carb on it and bolting it down and starting her up. But it can certainly be done without losing hp or efficiency. Some people put them on to gain those very things. If it's done right, you could GAIN 10-15. Hell, the old P1800s had dual carbs, and those used to outrun Corvettes. No EFI whatsoever. Oh and PS I live in NH, cars over 25 years old don't need any kind of smog crap. 1986=26 years old. And hey, what else could I mean by it's shot? It's broken, fuel pumps are inoperable. Bad wiring, everything. Gotta be replaced. Miht as well do something fun. And I say you ought to as well Tumbleweed, if it's something you really want to do. Although I'm not as familiar with the 940.

 

those p1800s may have beat the early 6 cyl corvettes, but they did it on weight and gearing, not power. with dual SU's they were maybe 100HP peak pre-smog. a mid 80s b230f stock with full smog is 118HP SAE Net in california configuration, and gets 25-27MPG pushing a big heavy 240 around.

IMHO, sidedraft carbs are nearly as complicated as fuel injection

 

I’m the opposite. I bought a 89 240 sedan with B230F Owner converted to carb and I want to restore it to original FI. Is this workable? I wasnt able to recover the original parts.

 

you'd probably need to find a donor car and get the manifold, ECU, ICU, harnesses, throttle body, injectors, air plumbing, air cleaner box, etc etc. depending how it was converted, the electrics could be pretty butchered. the donor could be any 89 or newer 240.

 

thanks for quick reply! Yes that’s what I thought. Looks like a big job. My consolation is I have an 85 Wagon with a B230F to use as a template. My other option is to buy a Penta manifold with Weber 32/36 from Ebay. Has anyone tried this? The previous owner left the original FI manifold in and made an adapter flange on which he bolted the carburetor.

 

I found these on ebay

Looks like it could work but the air cleaner sits too high. Might not allow enough clearance for the hood to close.


High mounting height of air cleaner

 

Hi,

I was wondering what ignition control unit to use for the 89 240 B230F LH 2.4 M47 and what harness and how to wire it all up if I convert to Weber 32/38 with Pierce manifold. Also, what happens to the ECU? Do I just disarm it and run the fuel pump power to the ignition switch? Is there an ICU and harness available specific to carb models? Thanks!

 

you'd need to replace the fuel pump with a low pressure delivery pump suitable for carbs.... you put 40-50 PSI into the float on that carb and you'll have gas *everywhere*.

punch a hole in your hood for the air cleaner, you don't want it sucking in hot air behind your radiator anyways.

 

Hi, thanks for reply. I plan to use the in tank pump with a pressure regulator and by pass the inline pump. Or, I could just use a carburetor specific Low pressure electric pump. My question is, how do I manage the ignition and is there a harness I could buy or do I have to make one up myself? Thanks!

 

I'd just run a distributor off a carbureted 740 or 240 - should bolt right up if I'm not mistaken.

 

so what, breaker points based timing with vacuum advance? I think the last vehicle I had with that was a 1966 VW Type III...

 

Could wire up a GM HEI unit to that to eliminate the points if so desired.

I still run points in my '74 Yamaha RD350 - thing runs like a champ, reliably. Starts 1 kick every time, unless it sits all winter - then it takes 3 kicks the following spring. Wheelies under power in 1st every time, too. I'd take that thing to CA from MA right now without hesitation if I had the will.

I like things I can repair with basic hand tools if needed. No magic box wizardry in that one.

 

lol, excepting that the RD350 is a two stroke with zero emissions plumbing and they tend to run better on lower octane so old fuel is no bother... My Stihl chain saw starts right up too - except when hot, betting the RD was the same. Modern FI cars know how to deal with temp changes, altitude changes, engine temp and all other conditions while maintaining driveability. I put 250K miles on my 84 Audi 4000Q with out ever having an issue with the K-Jet (only had to do injector seals and occasional cleaning of the IAV and throttle body). Personally if you want dirt simple, just install a small block V8... kits are available online.

 

There is not 740 that were carb. engines. Best bet would be to look at maybe the early Volvo marine engines otherwise you might have to look at trying to rig up a COP setup. Maybe look back to the earliest carb distributor and modify it to fit.