Carb or fuel injection?

[Werecow]

Want to use a 4.6 in a smog exempt vehicle. Trying to decide whether to keep the fuel injection or go with a carb. What is needed minimally, in the way of electronics and smog equipment, to keep the fuel injection on the car functional?

What would it take to convert the fuel injection to a carb?

Txs

 

[2000fordstanggt]

i dunno, but it sounds like itd be cool...if there was a benefit

 

[Rusty67]

If you are going to keep the EFI then I suguest to just buy a wrecked runner. There is no sense in trying to piece it all together. There are too many small pieces and you will be killing yourself trying to get them all. By geting a wrecked runner you know the system is fully functional with no error codes (in an idea situation) so what when you put it into the project you will be able to trouble shoot issues much more easily. I think once you do the reasearch and find out whats actually involved to get these things running with the EEC IV brains you might just scratch the idea of using stock EFI.

There are some sweet projects out there for EFI like tweecer but I think a lot of them are speed density systems as opposed to the MAF EFI setups which are more forgiving to the all the way around (especially for a novice).

If you want to carb a 4.6L motor there are kits for it. They run the distributor off the drivers side cam through the valve cover and have a carbed intake for the motor. I think Edelbrock makes a setup for it.

What car you thinking about puting this motor into ?

 

[DBMSTNG]

fuel injection is more efficient than carb. you'll make more power, the engine will run better, and you'll get better gas mileage.

 

[2000fordstanggt]

mhmm

 

[the98stang]

I agree with DBM...why sacrifice at that gas and power

 

[Rusty67]

Its a pain in the butt thats why. Carbing it makes it EASY to put into any car. There really isn't that much sacrifice in power and if carbs are tuned properly, the only drivability problems you usually get are major changes in atmosphere and elevation not being adjusted for. This usually isn't THAT big of a deal. You will definately lose about 1-3 MPG. More if you drive it hard all the time. Carbs make the same peak HP/Torque as EFI with no problems, you might lose some over all power throught the power band but max output wont change.

 

[DBMSTNG]

Its a pain in the butt thats why. Carbing it makes it EASY to put into any car. There really isn't that much sacrifice in power and if carbs are tuned properly, the only drivability problems you usually get are major changes in atmosphere and elevation not being adjusted for. This usually isn't THAT big of a deal. You will definately lose about 1-3 MPG. More if you drive it hard all the time. Carbs make the same peak HP/Torque as EFI with no problems, you might lose some over all power throught the power band but max output wont change.

you will lose power over the powerband because carb is just not precise enough to deliver the right a/f ratio at all rpm and load. EFI is not hard to tune at all and it's spot on at every RPM. there are reasons why carbs haven't been used in new cars for 20 years. it's just not efficient.

 

[Rusty67]

When I say pain in the butt I'm not talking about the tuning process, I'm talking about geting an EEC V engine to run properly with no error codes in a car that wasn't setup for it.

For starters you have to add a return fuel line and in tank pump system (in tank isn't neccissary but way better). You provably need to replace all or part of the feed line too because it wont be big enough or has rubber joints that aren't strong enough for EFI fuel pressure. Then there is all the wiring to deal with. What a nightmare that will be. What is it again ? 168 wires to the CPU ? And thats just for starters. There are a hole set of physcal issues I don't even need to get into.

Once the motor is installed an running correctly, ya its easy to tune. There are tons of options out there. Of course tuning it is the easy part. Its geting to the point where you CAN tune the motor that is the pain in the butt.