Idle around 1300rpm (X300 4.0L -95)

The idle could be due to an air leak in the rubber air hose between the throttle body and air filter housing, these crack over time and lets unmetered air into the engine may cause a high idle. Also clean your throttle body and clean your maf sensor it may help.

try by cleaning the throttle body, and Idle air control valve. to clean throttle body, Follow the plastic duct from the air filter housing up to the throttle body. Remove the duct and locate the throttle cables and rotating mechanism. Rotate the throttle mechanism and spray the cleaning solvent around the inside of the throttle body. Give it a moment to work and then wipe out the crud. but an old tooth brush works good to scrub around throttle plate. after it is sprayed, then wipe it out. you can use carb cleaner to clean Idle air control valve. do not push on it. just spray it good to get carbon off, and spray inside valve also. let it dry then replace it. Good-day!

sounds like your idle air control valve is defective, it controls your idle speed, Check around and get the best price you can. check your local auto parts or internet for the best prices.Eary to replace ,if you can operate a screwdriver you should be able to replace it youself..just a couple screws and a wire connection..

If you mean that the idle speed fluctuates, this is normally caused by build up of oil in the throttle valve housing. This oil is blown through the crankcase breather and gets worse as the engine gets old and wears. To remedy this remove intake hose from the throttle valve housing and clean out the oil build up in throttle valve housing in the area of the throttle butterfly. Open throttle valve to enable cleaning.

Follow top radiator hose, it goes directly to thermostat housing. The thermostat is directly under the housing.

oil sludge build up in throttle housing. clean out throttle housing.

Take a look at the rubber elbow on the back of the throttle body. It is under the plastic throttle body cover. This elbow can crack and allow un metered air into the system.

In this picture, it is just above the oval around the IAC



Also check the intake & air filter housing. If you just replaced the airfilter, the intake could have an air leak after the MAFS ( Mass Air Flow Sensor ). The MAFS is in the housing that the air filter is in.

You need a 10 mil and 8 mil spanner, carb cleaner and mabie some wd40.
Remove the big hose which goes from the throttle body to the air filter housing. Under the throttle body there is a idle control valve, unplug it, spray some wd40 on the 8mil bolts and take them off. Clean the idle control valve and housing and anywhere else which looks dirty, dry it with a lint free cloth and then put everything back on.
remove the battery negative terminal and leave it off for 30 minutes, this will reset the ecu to factory settings.

On the top of the throttle body there is a black circular rubber screw cover, take that off and there should be a plastic screw.

Connect your battery and start your engine, unscrew the idle speed control (plastic screw) so it revs at 2000rpm cold. When the temp needle reached the middle so it revs at 1000rpm hot.

This should solve the problem, if you drive around and find that you in 4th gear, with your foot off the accelerator and the idle is going up and down madly then the idle control valve is worn out and it needs replacing. Cost around £125 on ebay.

I had same problem with Scion. Took it to a Mobil One quick oil change place. Flushed injectors. It was under $100 and ran like new.

Dirt and crud builds up in the air intake around the throttle plate. It does not take much to choke out the engine either. (so you have to give it more gas) Take off your air cleaner housing and clean inside the air intake throat with some carb clener and a toothbrush.