| AUTOMOTIVE REPAIR INFORMATION: | | | | pattern. |
| Obtaining the auto repair information and | | | | MANIFOLD VACUUM TO TEST ENGINE HEALTH: |
| automotive parts you need to fix a faulty engine | | | | 1. Connect your vacuum gauge to an intake |
| requires you to accurately identify the problem | | | | vacuum port as close to the intake manifold as |
| behind it. However, when the problem is barely | | | | you can. |
| visible, this can be much harder than it sounds. In | | | | A running engine at idle should produce between |
| the initial stages of troubleshooting it is important | | | | 18 inches/Hg to 21 inches/Hg and the needle |
| to gain diagnostic direction, especially when you | | | | should remain steady. |
| are dealing with hard to identify engine issues. By | | | | Significantly lower readings or a gauge needle that |
| following the steps to properly identify engine | | | | bounces around are signs that further, more |
| problems, you will become a better diagnostician | | | | detailed tests should be done. |
| and save yourself time and energy in the long run. | | | | 2. Snap the throttle to wide open and release a |
| The following information will guide you in how to | | | | few times while watching the gauge. The needle |
| become a better engine doctor, allowing you to | | | | should drop to roughly 5 inches/Hg or less, |
| get your customers the answers they need | | | | rebound quickly and surge past the idle reading, |
| faster. | | | | then fall as quickly back to the idle reading. Any |
| Motor Age outlines three tests you can perform | | | | delay in needle response can indicate a problem |
| that will indicate if the engine you are examining is | | | | with airflow through the engine, usually in the |
| having difficulties. These tactics may even help | | | | exhaust. |
| determine what is causing a particular problem. | | | | 3. If this doesn’t work, hold the throttle at a |
| The first is an oldie but goodie – checking the | | | | constant 2,500 rpm. The gauge should read near |
| manifold vacuum. Next we encourage you to use | | | | the idle reading and stay there. Lowering vacuum |
| a relative compression test. And last but not least, | | | | readings while maintaining a steady rpm are |
| you should try reading the secondary ignition | | | | another indicator of a restricted exhaust. |