Carburetor conversion?

[Sockeyewillie]

I have a 85 4runner that the previous owner built from a 88 runner and it has a mishmash of the computer(88), injectors(?), o2 sensor(88 position) and test port(88) and I have never been able to get better than 7 mpg. I really don't go off road enough that the efi would come in handy and am wondering if converting to a carb would be a good solution.

 

[BucknutBob]

I would think finding out what's wrong with what you have would be a better idea. There's no way on this earth that a properly-functioning fuel injected engine in your Runner should get that bad of mileage. My 350 V8 did better than that. Maybe you need to find a salvage yard truck that you can scavenge a complete system from, or at least try a different ECU--from what I've heard, those years were very particular which computer you used when swapping parts. Even the V6 should get you well into the teens on mileage. People who swear by carbs are also willing to adjust them occasionally to adapt to changing circumstances, or simply live with their faults. Fuel injection may add complexity, but it also adds better driveability and control, and makes its own adjustments on the fly (when set up right in the first place, of course).

 

[SV_Dude]

I can't agree with bob more. Fix what you have. It sounds like you should get the same year efi system that was originally in your runner. Harnesses, ecus and sensors are somewhat easy to come by.

 

[mikebontoft]

nooo... I don't see why people get scared of efi and want to rip it out for a carb because it's easier.

Yours may be for the most legitimate reason I have heard yet.

 

[Sockeyewillie]

The engine runs great! smooth idle, starts exceptionally well, staggers at the top end when letting off the gas and clearly runs rich. I just bought new wires, plugs, cap, rotor, fuel filter, and o2 sensor. Lets see what this does. The o2 sensor is rigged from the ecu to the just before cat installation. I'd like to stick with the efi, but I was thinking of options. I don't know if I'm into ripping out the current wiring harness and ecu and starting over. Ugh.

 

[mikebontoft]

The engine runs great! smooth idle, starts exceptionally well, staggers at the top end when letting off the gas and clearly runs rich. I just bought new wires, plugs, cap, rotor, fuel filter, and o2 sensor. Lets see what this does. The o2 sensor is rigged from the ecu to the just before cat installation. I'd like to stick with the efi, but I was thinking of options. I don't know if I'm into ripping out the current wiring harness and ecu and starting over. Ugh.

I would suspect the 02 sensor is wired incorrectly or has failed. It's probably just stuck there sending a lean signal to the computer so it's always adding more fuel than it should. Or perhaps someone played with the VAF. (airflow meter)