How does the compression test work on a Dodge Ram?
How does the compression test work on a Dodge Ram? The PCM detects misfires by monitoring the crank sensor. As a cylinder fires the crank rotation speeds up. The PCM knows where #1 cylinder is on the crank tone wheel, so from there it knows which cylinder should fire next. If it doesn't see that acceleration that means a misfire has occurred. How to test engine compression in 5.2L V8? STEP 2: 26.25 = 26 (rounded to nearest one). STEP 3: 175 - 26 = 149. ANSWER: 149 PSI. Any cylinder with this compression (or lower) value will misfire. Since...