Hey folks!
I better introduce myself a bit, first post on this forum but found it a while ago, i own a 94 TR magna in its stock standard form at the moment.
Anyhow, thought I'd post a message here as it seems you lot might know might know magnas better than my mehcanic does..

I have this recurring problem in my 94 TR.
I'm not sure whats causing it but the end result is that when i drop the clutch in after having the revs up, or even after low speed manouvering - carpark, the revs will bottom out and the car will stall.
The the confusing part is that this does not happen very often, it was occuring frequently earlier in the year (warm temperatures around febuary-april) and i had the car looked at a few times and the mechanic couldn't seen to really find the problem, and the problem just faded away as the outside temperatures got cooler.
Its been a week of warm weather in perth and the problem is back again - warm outside temperature, drop clutch in, car stalls.

Admittadly my magna doesn't get to many long drives - mainly short hops between here and freo, so i'm thinking if i take it for a burn down the freeway it might help things a bit.

Anyway, just after some advice/ideas and it would be interesting to see if anyone else has had this problem!

Start off with your TB, is your Idle speed Motor working correctly, sometimes they are known to play up in the hotter weather.
Failing that I would be starting fron scratch and having every pin out on the ecu checked for consistantcy.
I had a SAAB sent to me many years ago that in warm weather would raun like crap intermittantly, after much searching the problem was the owner had used graphite in the ignition which had formed a trail behind the ignition and in warmer weather was giving a weak start signal and causing the start injector to fire up. The SAB dealer spent 60+ hours finding it then sent to me and I spent over 20+ hours before I found it through doing a ECU readout whe the problem occured.
This senario is different to our magnas in many ways but it shows how easy it is to get 1 idea and go with it when the problem is something else entirley

my car use to do that, but after i changed the radiator to coolant and not jsut crapppy dirty shit, it stopped it, it use to bottom out when it boiled....something like that.......but yeh, it still runs kinda stuggish on a hot day, like the last couple of days it seems sluggish, what could this be, is this normal?

I guess it could have something to do with the radiator - got toasted a while ago when the coolant leaked out - problem occured not to long after that.. though theoretically the radiator is now fine and i'm using proper coolant fluid.. just topped it up the other day to.

if thats the case the problem wont be your radiator, it will be the damage that occured to your engine when it over heated. all your radiator does is cool the water down as it runs through it. also if your radiator is boiling id say you either have a problem with your thermostat or a pressure problem. having water or coolant in it wont change squat. i love hearing people talking about coolant. it always makes me laugh. there is absolutley no reason for 99% of the driving population in australia to need to use coolant in there radiator. in our climate its only + is its anti corrosive properties. we dont drive any where it is hot enough, but more importantly where it is cold enough to need specific coolant. water is fine. however with all of that i would still reccomend you keep coolant in your radiator because as i said it is anti corrosive and contains less contaminants, plus nearlly all of you should already have it in there so just top it up, or replace it completly when you servcice your car.

The problem may be from an overheat and piston rings loosing the tension but having come from the EFI background the problem is heat transfer to the engine temp sensor. Dirty water does not conduct the temp as well as cooland thus the sensor is running on a cool reading, makes the mixture rich and the engine run like rubbish.
To say what the definate cause is with out physically looking at the car is impossable but first look at the basics, T Body, Idle Motor, Plugs, Leads, Dist, etc etc, most improtantly do not get tunnel vision thinking EFI EFI as in a lot if not most cases it isnot EFI related.

ALSO CHECK/replace your airfilter , if it's really annoying just wind up the idle speed!