I disconnected the ECU and removed ALL the plugs and wires (boots on mine). I cranked 3 turns for each cylinder, and when done repeated the test for accuracy. Disconnecting the ecu pretty much insures you wont fry it.
I am preparing to do the compression test for my car,never done such a thing before, i gathered some info about the procedure,and got some steps to be cleared if possible:
1- Is it better to disconnect all the coils and spark plugs,or is it better to test one cylinder at a time?
2- After the fuel system is disabled, and pressing the gas pedal then cranking the engine,do i crank till the gague holds to the highest reading,or there are nomber of strokes should be accomplished; 4,5...?
3- Are there any cautions or any additional tips for this procedure?
TIA
jj
I disconnected the ECU and removed ALL the plugs and wires (boots on mine). I cranked 3 turns for each cylinder, and when done repeated the test for accuracy. Disconnecting the ecu pretty much insures you wont fry it.
95 E34 530I V2.37
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Those who make peaceful revolution impossible will make violent revolution inevitable.
John F. Kennedy
Finally, today i carried the engine compresion test,as follows:
1- take the car for a spin till reaching operating temperature
2- take out fuse 23 till car stalled
3- disconnect battery
4- disconnect ECU
5- disconnect coils and spark plugs
6- connect the gauge
7- step on the pedal and give 3-4 cranks
I was alone doing that,i managed to see the needle jumping with each stroke, all the six cylinders went up to almost 10 BAR ( around 140-145 Psi), the compression didnt hold the needle steady,but after each stroke it went back to (0).
did i miss anything than having another extra hand around,and are the results satisfactory?
PS: after all is finished and everything is put back in order,the car operates
TIA
jj