Wont idle after warm

Try replacing the coolant temp sensor. It could be giving a false reading, telling the computer to add fuel.

The symptom of which you are describing is known as "hunting"
for idle.
You need an idle air bypass solenoid, otherwise known as an IAC. The part mounts right on the throttle body. Sometimes they can be cleaned, but for around fifty dollars, I would suggest a new one.

These maintenance intervals come from the maintenance interval calculator
at www.autozone.com, using a starting point of 25,800 miles (43000 km), and
assuming 1000 miles (1666 km) driven per month, and "severe driving conditions," which
are actually normal usage characteristics, such as frequent short trips, urban driving, waiting in traffic, driving in hot weather, trips under 16 km in cold weather, etc.

STARTING MILEAGE: 25800 (43,000 Kilometers)
Item
Action
Service History

20000 miles or 32000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate


21000 miles or 33600 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


24000 miles or 38400 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


25000 miles or 40000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate


27000 miles or 43200 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


30000 miles or 48000 kilometers

Battery Check
Air Filter Element Check
Wheel Bearing Lubricate
Steering and Suspension Lubricate
Fuel Filter Replace
Oil Filter, Engine Replace
Engine Oil Replace
Fluid - A/T Replace
Cabin Air Filter Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Cooling System Inspect
Wheel Bearing Inspect
Ball Joint Inspect
Drive/Propeller Shaft Inspect
Exhaust System Inspect
Steering and Suspension Inspect
Heat Shield, Exhaust Inspect
Tires Rotate


33000 miles or 52800 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


35000 miles or 56000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate


36000 miles or 57600 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


39000 miles or 62400 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


40000 miles or 64000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate



42000 miles or 67200 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


45000 miles or 72000 kilometers

Battery Check
Steering and Suspension Lubricate
Fuel Filter Replace
Oil Filter, Engine Replace
Engine Oil Replace
Cabin Air Filter Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Cooling System Inspect
Wheel Bearing Inspect
Ball Joint Inspect
Drive/Propeller Shaft Inspect
Steering and Suspension Inspect
Tires Rotate


48000 miles or 76800 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


50000 miles or 80000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate


51000 miles or 81600 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


54000 miles or 86400 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


55000 miles or 88000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate


57000 miles or 91200 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


60000 miles or 96000 kilometers

Battery Check
Air Filter Element Check
Wheel Bearing Lubricate
Steering and Suspension Lubricate
Fuel Filter Replace
Spark Plug Replace
Fluid Filter - A/T Replace
Oil Filter, Engine Replace
Engine Oil Replace
Fluid - A/T Replace
Cabin Air Filter Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Cooling System Inspect
Wheel Bearing Inspect
Ball Joint Inspect
Drive/Propeller Shaft Inspect
Exhaust System Inspect
Steering and Suspension Inspect
Heat Shield, Exhaust Inspect
Tires Rotate


63000 miles or 100800 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


65000 miles or 104000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate


66000 miles or 105600 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


69000 miles or 110400 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


70000 miles or 112000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate


72000 miles or 115200 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


75000 miles or 120000 kilometers

Battery Check
Air Filter Element Check
Steering and Suspension Lubricate
Fuel Filter Replace
Oil Filter, Engine Replace
Engine Oil Replace
Cabin Air Filter Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Cooling System Inspect
Wheel Bearing Inspect
Ball Joint Inspect
Drive/Propeller Shaft Inspect
Steering and Suspension Inspect
Tires Rotate


78000 miles or 124800 kilometers

Steering and Suspension Lubricate
Oil Filter, Engine Replace
Engine Oil Replace


80000 miles or 128000 kilometers

Battery Check
Oil Filter, Engine Replace
Engine Oil Replace
Vehicle Inspect
Brakes and Traction Control Inspect
Tires Rotate



And you can continue the pattern from there...

sounds like a bad idle control sensor.as long as you're driving it and giving it gas it runs somewhat ok right? it won't idle by itself,or it idles up and down by itself and then dies?thats a sign of a bad idle control sensor,some times they straighten up after the engine warms up and run fine.but eventually go completely bad and won't idle at all. hope this helps and thank you for choosing fixya.com

hi have you tryed the coil or even spraying dampstart over the plugs leads and coil all so put some red ex in the tank thanks ben

Well, there are a number of questions that come to mind from a routine maintenance perspective.
Seeing that it is a 1991, has the transmission ever been serviced. A complete oil change out and filter replacement should be done every 50K miles or so.

Let me know how many miles you have and if you plan on keeping the vehicle.
Regards,

in cold tems you need to make sure that you use a block wormer it will help alot

The idle issue is normal. The idle is controlled by the ECU. There are no adjustments for the idle. Regarding the knocking noise, that could be several things, and I am hesitant to comment without hearing it. Take it to a Toyota Dealer & have a tech listen to it. We are very good at identifying noises on the service drive.

probably oil, it may be too thick when it's cold but once it warms up it liquefies and your engine runs smoothly. you could try changing oil, I'm guessing if you have a high performance oil the chances this is the problem may be greater since high performance things are usually geared towards working well when everything is hot

you might wanna use a thinner lighter oil