hoping someone can help,im looking for info on the vacuum circuit of a 97 3sge.so far everything ive found is different to the motor i have here.this one has a valve on the throttle body that im assuming is the AC idle up.it also has 2 bimetal switching valves one on the water neck and one in the intake manifold plus some vacuum modulators that ive not seen on an mr2 before.yes the motor was from an mr2 and its from 1997.
any help would be appreciated,
cheers,
pete

If you have a look through the parts diagram here, it will probably help. You'll have to click through the image tabs to see the whole kit and kaboodle.
 
http://jp-carparts.com/to...cartype=3&fig=1708

Hi Pete.   I have a 1998  3SGE and yes its bound to be idle-up diaphragm. Hose from it to the white plastic backed valve in inlet manifold. Other hose from that valve to MAP sensor on rear firewall near diagnostic port.
Should have three vacuum ports on top of throttle body.  The two closest to front of car are routed to the exhaust gas recirculation system.  The other one goes down to the valve on the water neck if I remember correctly and controls the charcoal canister purge system.  Its been a while since I looked at this area.
Hope this is some help.
There are other VSVs down on back of inlet manifold too but that should get you started.
 Cheers.

thanks guys there are 3 ports on the throttle body and they all go to the places Falcon described,im not sure about that white plastic backed valve,from the diagram-it says its a gas filter and on my motor here one port goes to the map sensor but the other is going to the fuel pressure regulator not the diaphram on the throttle body,(thats why i thought it went to the AC idle up vsv on the rear firewall).i will get some pics tomorrow,thanks,pete

Checking small hoses:
Apart from the ISC valve operation maybe also check the routing of the small hoses on:
1. The fuel pressure activator (see pic)
2. The ACIS activator (see pic)
It is very easy for these to get mixed up.
You could also check the ACIS activation. The butterflies should be closed open with the motor stopped and the activator opens closes them when the motor is started. (You could watch this if someone else starts the motor).
Then above about 5000 RPM the activator opens the butterflies thus halving the virtual intake runner length.
 
Edit; I got it the wrong way round the first time lol. 
 
 
 
 

unfortunately for me the motors on a tyre under the carport atm,its due to go into a 1990 hardtop shortly i just need to make sure ive got everything in the right place,the engine harness had also been chewed on by a dog AND the last owner chopped most of the fusebox plugs off so thats making things more fun.
i had another good look today and its that white valve on the manifold thats confusing me,i took one hose off and blew threw it and i could hear air.i see one side of it goes to the map sensor and the other is going to the fuel presure regulator not the diaphragm on the throttle body,this has nothing on it and id assumed went to the AC idle up vsv however my wiring harness is chopped n chewed so its just a guess-my ecu has VISC on the 12 pin plug and that was completely chewed off..
thanks for all the info guys much appreciated i will update my progress
 
 
 

Hi Pete,
My 1996 car is likely to be very similar to your 1997 Engine.
I could possibly drop down sometime during the weekend, if you wanted to have a look.

It looks like you have a job ahead of you.
If you haven't done already download this:
http://www.mr2australia.com/mr2play/tm.aspx?m=87772
Useless trying anything unless you have it.
Check out pages  EG 266 to EG 274
 
Good luck!!

update-
the motors now in the car and runs...sort of.
it keeps throwing code 99,i think its factory immobilizer related but im not sure,never had an mr2 with factory immobilizer and cant find much info,has anyone on here had a fault code 99 and what did you do?
thanks in advance
pete