kendude33

I have an 87 GT that I have just rebuilt the motor for. The cam has been ground to be a little lopey, so that I can get a little more out of it. I have been told by several different individuals that I can stay with the fuel injection, and other individuals have told me that I need to convert to a carburetor. I would like some help. Will the lopey cam cause the computer to malfunction if I stay with the EFI? If so, what is involved with the conversion? I have a pressure regulator to reduce the PSI from the electric fuel pump to the carb. Will I need to hotwire the fuel pump since I am no longer using the EFI? As well, since I am going around the computer, will I also have to do something with the distributor as it is dependant on the computer? Any help with this will be appreciated.
kendude33

87Stallion

If you are wanting to convert to carb, you will need a dizzy from a 85 Mustang Carbed and a ignition box.

I used a 85 dizzy and a duraspark II box.

Take my advice if you do decide to switch to carb don't use the stock EFI fuel pump. I already tried that. I couldn't get my fuel pressure to be consistent enough.

kendude33

Thanks for the tip. What is a dizzy?

87Stallion

Dizzy= distributor

redpony88

instead of bothering to wire up a stock box, just go get a MSD, Jacobs or something. you will also need the plug for the distributor, just go to a junkyard and look for ANY old ford with a carb and you should find the plug, it's a 3 prong plug. then just follow the aftermarket box's instructions on how to wire it up. the reason you need a 85 distributor is because it's vacc advance instead of computer, make sure the parts guys know its for a standard 85, the autos had a different distributor.

also fyi there is a search feature, and there are alot of these threads on efi to carb, just check those out instead of having to wait on new responses.

AdamB

I haven't needed to convert to carb yet. If you have a computer controlled car, I'd stay that way. If you have a carb'ed car, I'd stay that way. Unless you have lots of $$ to throw around, don't change. If you are carb'ed, change jets, if you're EFI change tunes...

The only thing I'd change if I was adding a cam and going to stay EFI would be to switch from a MAP system to a MAF system. A MAP system monitors engine vacuum to adjust the AFR, and a MAF monitors actual incoming air etc. The MAF system is a lot more sophisticated and has better learning capabilities.

Shelty

I'd stay with EFI, its easier than having to convert, which takes a good deal of work...

and while its apart, convert to Mass Air, if you ever dig more into the motor with mods or throw on a blower, it will be easier to tune than Speed Density