Hello again,
Well a vacuum leak or unmetered air leak is any air leak entering the engine before the combustion chamber. A good way to check for a vacuum leak is to get a small propane torch. Please use extreme caution and proper safety gear when doing this troubleshooting. Barely crack open the nozzle on your propane torch, making sure not to light it. You just want the propane to be coming out. Have an assistant start your vehicle. With the engine running, pass the propane torch around the air-box, air intake ducting, throttle body, intake manifold, and all vacuum lines and pipes. If there is a leak, when the propane torch passes by it, the engine rpm's should momentarily pick up as the propane is ingested into the cylinders and consumed in the combustion process. Let us know what you find out.
Thanks,
Alex,
2CarPros
Wednesday, February 6th, 2019 AT 9:32 AM