This week we did a compression test on the carburetor engine.
1/ I disconnected the spade terminal going to the coil so the engine would just crank over and not start.
2/ Then all the spark plugs were removed to ensure accurate results.
3/ I put a compression tester where the spark plugs usually sit and applied pressure to the gauge while my partner cranked over the engine about 4 times to build up the compression.
4/ Then I did it to each cylinder and compared the results which was less than 10% difference between the cylinders.
A low compression in one cylinder would tell you that the exhaust valve isn't shutting properly.


We also did testing of Inputs and Outputs using the Multimeter.
One of the sensors we tested was the Throttle Position switch (TPS)

With the Multimeter on DC Volts we tested between the VTA and E2 on the circuit board While the engine was off but the key in the accessories position.
You should get a reading of 0.5V or less when the throttle is fully closed and 3.5 - 5.5 when the throttle is fully open.
This is just telling you how many volts are given to the TPS to keep the throttle open or closed.
I got a 0.3V reading when closed and 4.1V when open which meets the manufactures specs.