my cis to efi conversion

[Alan Cottrill]

I'm getting pretty close and just wanted to share my progress as it is finally coming together.

I piecing mine together slowly but surely. tonight I got the intake put together. The throttle body is from a GM, I think a pontiac. I did an engine swap for my father in law last year and the core was still sitting in my garage. I got to looking at it and it had a throttle body with a TPS and 6 injectors. so I figured what the heck they look like they'll work. I just built a plate to adapt the TB to the bottom of my blown cis air box.

I know it's not the most elagant looking setup but it'll work for now until I find an individual intake runner soultion. I'm going back and forth between modifying MFI throttle bodies and just biting the bullet and buying some TWM throttle bodies.

[Doug Zielke]

Looks pretty "elegant" to me.
As much as I respect my CIS, when it finally becomes too much to keep alive, I will go for EFI.
Let us know how it actually performs, Al.

BTW....Yakima is just a stones throw from the heart of this years SCWDP Round-Up. Hope you'll join us!
http://members.shaw.ca/zielke/roundup.html

[rdane]

Alan are you doing the PCA wine tour this weekend? I would like to see your car and handiwork.

[Alan Cottrill]

not going to be able to make the wine tour. Hopefully you guys will get some good weather for it. we've had heavy rain and thunder storms every night this week.

I will be at the round up for sure.

[slope-nz]

Alan, I am instred in your thought's on the mod's on MFI t bodys. I have a 2.7 RS with MFI and I cant help but think that that EFI conversion might be the best of both worlds. Thanks Randy

[Alan Cottrill]

my first thought on mod'ing MFI TB's is to not mod them at all. just buy some aluminum turbo injector blocks that are made to hold EFI injectors, get some longer intake studs, and put the MFI TB's on top of the injector blocks.

[slope-nz]

Alan, this seems like a reasonable way to solve the injector mounting problem,but what about the fuel rail ? Thanks Randy

[Lukesportsman]

Look at the thread on efi to 930 for what's involved in EFI rails. You could go with soft lines just like many MFI systems of the past did. They also do sell barbed injectors though the selection is probably limited to OEM applications.

Where would you place the TPS?

[Alan Cottrill]

Soft lines would be the cheap/easy way (the way I prefer). You could spend some bucks and buy the rails that go with the blocks.

Depending on what type of cam you'd be running you can get away without the TPS. Tony (tibtz) has the software for megasquirt to do it.

If you get to wild with the cam you'll have too much fluctuation in the manifold vacuum and MAP will be useless. At that point you'll need to run in alpha-n mode, which uses TPS and RPM for the VE table.

If you had to have a TPS you would have to get creative. You could get away with using any potentiometer with the proper resistance range, figure out a way to mount it and use a lever to attach it to the linkage somehow. I know "easier said than done” but with a little effort I'm sure it can be done.

[slope-nz]

Luke ,Good question, I'm not sure that I really understand how the TPS works ( is it mch. or electronic) so I dont know how to mount it.I have spent a fair amount of time thinking how to make this conversion but I find that every step just creates it's on problems. Never the less I feel that EFI would make my 2.7 RS a real sweet heart. Randy

[Alan Cottrill]

The TPS (throttle position sensor) is a variable resistor that tells the ECU the position of the throttle. so... It's mechanical and electrical.

It's typically attached to the end of the throttle plate shaft.

[slope-nz]

I though that the TPS would be some sort of varistor, so now I have to ask if my 2.7 RS cam would work with the megasquirt ? Randy

[67nin11]

any updates on this project??