JJacobs said:
sigh. Yep, they'll do that.
Go figure, it happens when things aren't working right. Very insightful. With that out of the way:
Assuming everything is connected as it should be, do the usual stuff:
- Clean the throttle body.
- Clean the IAC; replace if necessary.
- Make sure the TPS is working properly; replace if necessary.
- Ensure that the PCV system is clean and working.
- Check that the EGR valve is connected and functional; clean or replace as necessary.
- Check that the thermostat operates properly, that coolant levels are good and no air is trapped in the system (you've got the closed cooling system, so this is
possible), that the water pump isn't disintegrated, and have the radiator pressure- and leak-tested.
- Investigate the condition of the distributor cap, rotor arm, plug wires, and plugs. Make sure everything's in good condition and/or within spec. Replace as necessary.
- Look for signs of head or gasket failure: bubbles in the coolant with the engine running, oil in the coolant, mayonnaise on the underside of the oil filler cap.
- Check that the oxygen sensor is functional; replace if necessary.
- Check that the catalytic converter is functional; replace if necessary.
A little better description of the symptoms and what you've tried so far would go a long way in troubleshooting them. This sounds like it's probably a multi-layered issue, but it's hard to tell at this point.
