mechano-nut is right.
If an engine won't build decent cylinder pressure, it won't run. The fuel/air mixture must be compressed before it will burn and make the engine run. My post assumed that the engine had compression. Check that first!
A compression tester is available at all auto parts stores for 20 to 30 bucks. It has a high pressure gauge on a 1 foot piece of high pressure hose. The other end of the hose screws into the sparkplug hole of the cyl under test.
To check compression, remove all 6 sparkplugs. Disconnect the wire that goes from the coil to the distributor to prevent sparking during test. Block the throttle wide open. Make sure battery is charged to get good readings. Screw the gauge into each cylinder in turn, and crank the engine over until the gauge reading stops increasing. The pressure difference between the cylinders should be within 10% of each other.
For example, if the highest reading you get out of a cylinder is 130 PSI, the lowest reading in any other cylinder should be
130psi x 10% = 13psi
subtract 10 percent reading from maximum:
130psi - 13psi = 117psi minimum in any other cylinder in a healthy motor.
For a worn motor, the pressure may be much lower. A ballpark figure for a worn motor to run is least 85 PSI to run at all. But the readings should still be within 10 to 15% of each other.
If all but one or two cylinders have good pressure, then the problem is in that one cylinder. It could be stuck valves, weak valvesprings, misadjusted valves, blown head gasket, cracked piston rings, cracked head, etc.
If the motor has good, even compression across all 6 cylinders, go back to troubleshooting the fuel and ignition systems. If the engine has low compression, then you must correct the internal malfunction before it will run.
The reason I asked about intake rings is because if you tried to put the wrong intake on the motor, the intake rings wouldn't let you, cuz they wouldn't line up.
hope this helps
chip
