I replaced the clutch in my 94 Ranger, but after test driving for 15 minutes, although the clutch worked great, the engine was running very, very rough. The upper radiator was swelling and I thought it was going to explode. This would possibly indicate a blown head gasket or a cracked head. So I stripped my truck of its drive belt and outer timing belt cover just to check on the timing belt which showed to be about 2 or 2 1/2 teeth off. But anyways, before I change out the timing belt, I wanted to rule out a blown head gasket or cracked head by doing a compression check.

I am confused about a couple of things.

First, to disenable the plug wire coil packs, I guess you just unplug the electrical from each coil pack. I have the 1994 V4 2.3 and the coil packs are right by each other on the passenger side of the engine. The electical inputs are simple to see and simple to unplug.

Second, I think I am supposed to disable the fuel system to make sure it doesn't flow. I think just taking out the fuel pump relay fuse in the power distribution box should do this. Can anyone confirm this?

Third, there is always airflow and to check compression, I think it should be important that air cant leak out secondary places, like open spark plug compartments. So can anyone confirm that I need all 7 spark plugs in and tightened? Obviously the 8th spark plug compartment would hold the pressure gauge?

Finally, to check compression, I need to crank the truck with my one foot on the clutch and one on the gas pedal, probably all the way to the floor to open the throttle. Can anyone confirm that I would need to hit the gas pedal to the floor when attempting to crank?

Because I am in the middle of changing my timing belt and thermostat, my drive belt is off and the upper radiator hose, along with the thermostat housing, are disconnected. I'm thinking about at least reconnecting the thermostat housing and the upper radiator hose to ensure the coolant in the engine doesn't end up all over my garage wall when I crank the truck.

Any suggestions or answers to my questions would be greatly appreciated.

 

Disconnect coil packs, remove fuel pump relay, either hold pedal all the way down or temporarily wire throttle to wide open and hold down clutch pedal. Remove one plug at a time and when testing crank the engine the same number of revolutions for each cylinder.