khelms

Swapping low miles 89 engine into my 86. I took at least one too few photos of the 89 before replacing intake manifold gasket. The 89 Throttle Body has 3 hose connections on right side and my 86 only has 2. I think the top connection on the 89 is for the crankcase ventilation and the bottom connection is for the coolant. Not sure about the middle hose outlet. I would like to use the 89 because it has less miles than the 86 throttle body. Thanks for the help.
Keith

don hall

May not be of any help to your specific concern, but this link
is about a 1989 L98 rebuild with many photos:

http://www.corvetteguruforum.com/mod...post_id=121677

Matatk

Wow, what a great link

The top outlet on the TB does go to the passenger side valve cover, the middle one has a hose that runs underneath and connects to the evap system by the driver's side headlight, the bottom outlet is for the coolant.



Matthew

khelms

Thanks for the link. There were a couple of helpful photos. It looks like a vacuum line that crosses under the throttle body to the left side of the engine. I'll look through my table of parts and hopefully figure it out or perhaps someone else will provide another clue. I really appreciate you taking time to respond with helpful info.

Matatk

Also as a side note, there was a change in linkage over the years, I would have to look up specifically when it occurred, but be aware your throttle cable/etc might not hook up correctly.

khelms

Thanks so much for the great diagram and the helpful explanation. I really appreciate you taking time to respond with the information I needed. There are some very knowledgeable and helpful folks on this forum.

Keith

khelms

Thanks for the heads up about the throttle linkage. I will pay attention to that when I get the 89 engine swapped in.

vetteoz

You will need a throttle cable to suit the '89 + TB which uses a different fitting on the throttle linkage to the earlier TB's

No need to change anything
You can reuse the plumbing arrangement off the 86 and just plug the new middle vac port on the '89 TB
All the later setup did was add a dedicated vacuum port for the canister purge instead of coupling it with the PCV vacuum as done on your car
Observe the T on the line that goes to intake on Drv side; one side for purge / the other for PCV

See
http://i171.photobucket.com/albums/u...acuum85-86.gif

khelms

Thanks for great info and all of the great diagrams and annotated photos.
I did see tonight how the 86 used a T line to combine the PCV and the canister.
I did not study the throttle linkage tonight. I will plan to take a look at that tomorrow night. Is the difference in how the cables actually connect to the throttle body or is it bracket that mounts to the plenum. Is the cable that connects from the throttle body to the transmission also different?
Thanks again for the valuable assistance. Y'all are saving me lots of time and frustration.

Cliff Harris

They changed the way the vacuum connections were made to the canister purge control solenoid. The connection to the tank pressure control valve also changed.

Here's the diagram for an '86:

vetteoz

Yes
See pic here
http://www.hotrodlane.cc/Streetstories/choosingtpi2.htm

The early cars have a cable end that fits on ball stud as used on a carb.
The later cars have a pin that fits in a slot on the linkage and then the cable lays back in a groove on the linkage

The cable bracket and TV cable are the same

NB ; You can't easily change the linkage arrangement short of
cutting and welding which is why the correct year cable is suggested




As I already noted above and linked to the early vac diagram

khelms

Thanks for the link. Those are some good informative photos.
I did look at both throttle bodies and the cables this morning and saw exactly what you described. I think I will end up using the 86 Throttle Body so I can use the cables I already have.
I really appreciate your help.