More Noob Questions

So I've got some more noob questions:

• What is the correct front/rear tyre sizes for a 1990 N/A model SW20?  The speedo is out so I suspect it has the wrong tyre size on the rear but there is no tyre placard or owner manual
• I can't find a hose kit for the 3S-GE (non-turbo) but plenty of kits for the 3S-GTE.  Can I use the 3S-GTE kit or are they different?
• The straps that hold the roof panels behind the seats are missing, I only have one end of one strap.  Does anyone have a photo of what they look like or where they attach to?
• The engine doesn't rev out, it revs cleanly to about 5,000 rpm but then just runs out of power, I presume this is because the variable inlet manifold is not working.  Is there any other common cause?  Is there an easy way to hold the variable manifold open to check?

 

I assume you mean it won't rev past 5000 in say third gear at WOT?
When was fuel filter last changed? Air cleaner?
As Mike says, start by replacing all normal serviceable parts. Distributor cap and rotor, correct spark plugs etc.
Then check high tension leads and especially the master lead not only for resistance but also that their connections are clean and not corroded.
Check ALL vacuum hoses for cracks, leaks etc. Down low at back of inlet manifold there should be a couple of VSVs. Check their filters and that their vacuum hoses are correctly routed. BGB has info.
To check the actuator on inlet manifold for correct operation.  1. Engine off. 2. Observe actuator position. 3. While watching actuator, have someone start engine. 4. Actuator should immediately snap closed.
You could also disconnect and plug the actuator's hose and take it for a drive ?
A partly blocked CAT or exhaust muffler could also cause this symptom.
Incorrect cam timing is also possible but very unlikely.

VSV  = vacuum switch valve - see pic below.
The pic is actually from the Gen 3 engine service manual but your car is much the same
 
BGB (big green book) 1991 SW20 service manual.
Download free at:
https://www.mr2oc.co.uk/forum/198/80372.html
Although US based, still generally applicable to the ADM cars.
 

JME
 
Thanks for the info, it's much appreciated.  I'm downloading the book now :)

 Do yourself a favor and go get it printed and bound, makes life SO much easier when working on your car. 
 

Might be worth putting it on a dyno and look at the fuel ratio report to see if fuel or air is the problem.