So far I have:
- Checked for vacuum leaks and replaced all vacuum hoses with new silicone hoses and new clamps. I removed and thoroughly checked the intake boot.
- I noticed that there is no change at all in engine speed/operation when I remove the oil filler cap or dipstick, which makes me think I have a serious vacuum leak somewhere.
- Checked the ICV and tested it to make sure it's working.
- Checked the Throttle Switch and replaced it with a new one (the old one worked but was filthy and old). The checked the new switch with the multimeter.
- Replaced the throttle body gasket.
- Checked the torque settings on the rocker cover nuts.
- Replaced the blue coolant temp sensor.
- Flushed and bled the coolant system.
- Replaced the O2 sensor - this didn't fix the idle but it made a noticeable difference to the amount of power the engine was making. Seems far more lively now.
- Checked the spark plugs - they look quite black but I don't know if that's because the engine was running rich with the non-functioning O2 sensor previously. I'll be replacing all the plugs on Monday so I can determine if it's running rich or lean.
- Spent an hour trying to do the "stomp test" before learning that it only works on US cars
- Filled tank with fresh fuel 98 octane fuel.
My next steps are:
- Get the engine professionally smoke tested for vacuum leaks.
- New clean spark plugs with checked/correct gaps.
- Check crank position sensor.
- Have fuel pressure checked in case the fuel pump or fuel pressure regulator are shot.
- Replace fuel injectors and O-rings (they look very old, they're noisy and they have surface rust).
This has been a real hair-puller for me, if anyone has had similar problems or has suggestions for other things I need to check I'm all ears!
