Throttle body mod question 3rd gen
 

I'm replacing the mostly dead engine in my 2000 SW2.
I had thought the donor car was a 1999 but it turns out it's a 1997.
I've worked out all the changes so far that have to happen to make this work except the throttle body.
The problem is the position of the throttle cable arm on the shaft. The one is 180 degrees off from the other.
See Pic:

https://cimg4.ibsrv.net/gimg/www.sat...e7778055cf.jpg
The 3rd gen 2000 is on the left, the 2nd gen 1997 on the right.
It seems if I can pull the plastic arm off the shaft and rotate it 180 it'll work.
Has anyone ever done this?
It's either that or make a new throttle cable bracket for the 2nd gen TB.

I believe the part of the throttle body with the spring that is connected to the piece which moves the throttle cable has its movement limited by a physical stop. I don't remember if it is itself part of the throttle body but I think it is. If you rotated that outer piece 180°, I think you'd have to come up with a new physical stop and a different cable length.

Brain dump

Does it use the same TPS and IAC valve?

If not, the voltages read by the PCM may mean different things to a 2000 PCM than a 97 PCM. May.

You pretty much have to use the PCM and BCM from the 2000 as the 97 has no BCM. 97 also did not have pass lock so again 2000 takes it.

I'm not sure how you integrate the smog pump onto a 97 engine. Never really looked at one. I believe they started in '98 so you could look for a 98 build as a reference.

Remember that the internal design of the third generation S car engine is pretty different. At least the head. Don't think it matters unless the 2,000 PCM has some type of static offset built into the programming that would not apply to a 97 engine. This is total speculation on my part but something you might want to check before you start.

That's about it for the brain dump for now.

Not willing to take the chance of ruining one of the gen 3 throttle body trying to flip the arm I stopped by pick-n-save today to grab another one to experiment on.
I wanted to get a 2nd gen throttle body since they have had several of them for few weeks now and I thought that I would at least gain a replacement for the broken TPS on the '97.
I get there and they're all gone. Instead there's a 1999 and 3 of the 2002 Saturns. Not only that, all but the '99 are DOHC cars.
Uggh!
Anyways, out of curiosity I took a look at the SOHC '99 and notice that not only does it have an aluminum instead plastic intake but the throttle body looks like the one I have on my 2000 (same two port vacuum connection and same IAC and TPS).
It's mounted sideways like the one on the '97 and has the cable arm rotated 180 degrees - matching the orientation of the '97.
I snatched that thing off of there and took it home.
I compared it to the other two and the mounting holes match the '97. The bore is identical (at least within a millimeter). The TPS seems identical and the IAC is identical to the 2000.
Looks like you can use a '99 (and maybe later) SOHC throttle body to make a 2nd gen engine work in a 3rd gen body.
Pic of all three with the '97 DOHC on left, '99 SOHC in middle and the 2000 DOHC on the right:
https://cimg6.ibsrv.net/gimg/www.sat...123b03fb5b.jpg
Throttle bodies, '97 DOHC, '99 SOHC, 2000 DOHC left to right

So it appears I have a fix for the throttle body issue.
I still don't know if the arm can be flipped.
I'll check that out later and report back what I found out.

The vacuum Port holes at the top look to be different. You'll have to go back and get the vacuum connection piece I do believe.

It's just the rectangular black rubber piece that is still present on the right hand throttle body. I've already swapped it over.
I did confirm that the TPS is a different part number between the '99 SOHC and the 2000 DOHC. Fortunately they swap over with no issues.

So here's the 1999 SOHC throttle body on the 1997 DOHC intake with the 2000 DOHC TPS and IAC.
I think it worked out pretty good.

https://cimg0.ibsrv.net/gimg/www.sat...b69d1b72f8.jpg
1999 SOHC throttle body on 1997 DOHC intake.

Good luck with your project!

Which throttle body gasket did you use? The one from the 97 DOHC or the 99 SOHC?
Just trying to help document this for those that see it later in life.

I reused the gasket that was still stuck on the 1997 intake. Both the '97 DOHC and the '99 SOHC looked identical to me (I didn't think to take a picture at the junkyard).
Having examined all three throttle bodies in detail I'm confident that all of them would work with the '97 gasket on the '97 intake.
The only remaining issue directly related to the throttle body swap is the vacuum line that connects to the double port on top.
As you can see in the picture, the one from the 2000 doesn't really work (bends are wrong) and the one from the '97 engine has too many ports.
I'll figure something out and report back with the solution.
In a different thread I will detail the entire engine swap showing all the changes I had to make and highlighting some of the things that remained the same.
I'm up to almost 1/2 gig of photos of the process so far.
Tonight I will attempt the throttle cable arm removal and rotation on one of the spares to see if it can be done.

I thought you were using only the engine from the 97 but you mentioned you used the 97 intake manifold. While you have it out of the car, you can save yourself a lot of hassle by replacing the intake manifold gasket. You have no idea what shape it's in and it's much more of a pain in the ass once it's in the car so I would pull it off clean the surfaces get a new gasket and just do it. Just did my 95 in the car. Not exactly enjoyable.

Too many ports usually means used for additional functions.

Be careful with the throttle body spring. I would not at all be surprised if it is under partial tension as installed just sitting there.