ok so i have had this problem since i have owned the car, for like 3 months now but it is slowly getting worse it seems.
the car is a 1990 tii.
the problem that i am having is that the car does not like to start at all when it is cold, it usually takes me about 3-4 tries to start it and get on the gas to keep the motor from dying and then i usually sit at about 3k rpms for awhile unti lthe motor gets a bit warmer and it will usually idle ok after that. but when i say this issue has gotten worse what is happening now is it takes a few more tries to get the motor to actually start up and when i do and rev it up to 3k to warm it up and let off it is not idling very well, it will usually drop down to a 200-400 rpm idle and bounce up and down to 750 or so for a few minutes until it stabilizes at the normal 750.
i also see the idle bounce sometimes when it is totally warm but it has not died yet, but is also very annoying and am sure given time and the problem getting worse it could very well die sooner or later.

here is what i currently know is wrong with the car:
has a small exhaust leak that i do not know exactly where it is
and it has a coolant seal blown and has been since i have bought it, i usually refill the over flow to the max level(not the top the max level marked on the tank) every 2 weeks.
i have an oil leak somewhere around my turbo, it seems to be leaking near the wastegate
it also has a boost leak somewhere that has started in the past 2-3 weeks...

i am pretty lost on this one but the only thing i can think it would be would be a/f ratio is off, so i am thinking an o2 sensor?
i was thinking for a long time that the coolant would just build up inside my housings and in the morning it would start hard due to it collecting and having to be pushed out, but with my erratic idle problems it makes me question that.

any help would be appreciated thx

 

Vacuum leak is ur issue its causing the system to take in too much air at initial start up and the system then corrects itself but thats only cause ur BAC valve is set at current setup. once u fix all leaks, you'll notice ur idle will be higher (i think) set ur BAC valve to original idle as recommended via FSM, and check the TPS to make sure that is set properly (cant remember the correct settings its been a while - 3 years).

Once thats done report back if u have any problems....man i miss rotaries T_T. They had problems but they were soo much fun to troubleshoot.

 

This sounds exactly like what is happening.

 

ok so i got my hands dirty already.
i want out and took a look at my bac and it turns out it wasn't even plugged in...
i plugged her in and started her up and i did have to go through my whole start routine but it did seem to steady the idle muuuuch faster, which is good.
i am pulling 15 inhg at a cold idle right now, and i do not believe i have any vacuum leaks because there is no hissing noice coming from anywhere in my engine bay.

 

Lack of a signal from the water thermo sensor on the back of the water pump HOUSING, will cause similar problems.

The ECU uses this sensor for determining the amount of fuel used during START. If the sensor is unplugged or one of the connectors two wires is pushed back in the connector, then the ECU will not deliver enough fuel during COLD starts. Warm or Hot starts will be normal starts.......'cause the ECU will default to a temp of 180*F if it does not see this sensors signal. That's why HOT or WARM starts are good and cold are bad if the sensor is disconnected.

 

will check that hailers.
want to thank you guys for the help, in telling me where to look.
i still have the problem but with the bac acting as a helper system my idle flattens out much quicker and i have no had any issues while driving yet.
i've got a little bit of a budget project going on here right now but i also use the car to dd unfortunately.

in the past week i have gotten alot done
-battery relocate
-new brake pads
-new tires (fatties in the back)
-replaced ALL old screws and bolts because alot of trim pieces were missing screws
-pulled my a/c

now i just need a cone filter and compression tube and i can mount my front mount.

 

Save for a engine rebuild before doing all this extra work. Why bother with the work if your coolant seal is on its way to full failure?

 

the motor either makes it to the end of summer or it doesn't, i don't really care either way because the cost of a low mileage motor on ebay is just a couple hundred more than the cost of a rebuild kit. either way i will be tearing down this motor whether it has gone to **** or is still running end of summer.
until then i just bought a dd like an hour ago, and i will keep working on the rx because i enjoy having a hobby and a nice car.

now i can drop my trans and put my stage 3 clutch in

 

Check the resistance of the water thermo sensor (backside of the thermostat housing) against the specs in the FSM at various temperatures. If those are ok, check the voltage from the sensor at the connector to the ECM. Both values are in the factory service manual online.

It is supposed to be high resistance at low temps, and the ECU uses that information to increase the open time on the fuel injectors in cold start operations to richen the mixture; as the temp comes up the resistance goes down and the ECU leans out the mixture appropriate to normal idle.

If the resistance is too high/open, the ECU will see that as a very cold temp and richen the mixture too much, and it will be difficult to start due to a too-rich mixture.

Then again, your coolant leak may be the real culprit.

 

Just a hint:
My thermo sensor was unplugged and it did the exact same thing. It took several tries to crank every single time.

Do you know what the compression is?

How is your afm and injectors?