O.K. First with the rough drivability:
Since you've eliminated the ignition system (?) As the source of your problems, it's time to check the fuel. Throw on a fuel pressure gauge and compare to spec. (Checking the fuel pump, filter and FPR)
Also, if the gauge needle is fluctuating rapidly, and pressure is out of range while accelerating, suspect clogged fuel injectors. You can do a cylinder drop/balance test to isolate each injector. (If you're not familiar with that procedure, write back and I'll walk you through it)
As for your "No heat":
Have you done a system flush? With the thermostat removed, connect a garden hose and flush the system. (Turn the heater controls on "HIGH", no a/c.) Check to see that water flows freely through the system. If not, then the heater core and/or the radiator could be clogged.
Also, is there ever an unexplained loss of coolant? If so, you may have a blown head gasket. When these motors blow a gasket, the exhaust gas is forced into the coolant system and the air bubbles get trapped in the heater core and radiator. This prevents the coolant from circulating correctly. (And will cause overheating after sustained driving over 60)
To do a quick test for this, remove the radiator cap or surge tank cap. Look inside as someone revs the motor to at least 1,500 r.P.M.S. If you see large bubbles, that's exhaust gas. (With a blown head gasket, coolant doesn't always get into the oil)
Monday, February 22nd, 2010 AT 8:02 PM