Was the 2.5 iron duke ever used in an MPFI application? It was so widely used across GM's small car line that I'd figure that there has to be something out there

I do not believe there were any MPFI Dukes.
I may be mistaken, but I am pretty sure there was not.

I believe there was an intake manifold that had injector bungs that fit the Duke and SD4. The 2.2 is the closest you are going to get to SFI without having to fab up your own stuff or fiddle with ECMs not designed for it.

The SD manifold has injector bosses built in, but were meant for mechanical size injectors. I'd be leery about using a 14mm bore injector in the SD manifold bosses, as they wouldn't have much material remaining. So instead I added injector bosses from SDI to the underside of the manifold. It's pretty flat there so it's easy to do.








Not terribly hard, if you want to consider the SD manifold.

Those are some awfully strange looking injectors! What's the reason for the housing, does it eliminate the need for a fuel rail?

A few years ago, I collected all the parts I needed to fuel inject an Olds V8 engine, including a correctly rewired harness and stock 1227727 GM ECM. I did a great deal of research into the operation of the stock system but I never was able to get it to run because of hardware problems and fuel leaks.

I still have all of these parts and I'd like to try something with the Fiero to increase efficiency. This would use stock high-Z electrical solenoid injectors sealed with standard O-rings.

Do you think there's enough material in the stock intake to drill for bungs and weld them on? If not, maybe I should look into the SD intake, but I'd like to do this on a low-dollar budget since I know these projects usually descend into high-dollar money pits

As far as I'm concerned, TBI is only one tiny step ahead of a carburetor, so I'm very interested in figuring out a way to get one injector per cylinder.

[This message has been edited by carcinogen (edited 06-24-2008).]

quote Originally posted by carcinogen: As far as I'm concerned, TBI is only one tiny step ahead of a carburetor, so I'm very interested in figuring out a way to get one injector per cylinder.

It's still a wet manifold!? I'm wondering what we can expect with 4 injectors? Being a diesel guy I would push the line to direct injection. I've always found jap CV carbs to be near perfect. The TBI is a wonderfully simple setup. The extra complexity gets what mpg and hp improvements?