1991 Mitsubishi Galant VR-4
CoDSM Intake Leak Testing

This is just copied from an email description I wrote. Pictures coming soon. Okay there is a VFAQ on leak testing but here is how I build a tester and leak test. First an intake leak tester goes right on the inlet of your turbocharger instead of you intake snorkel or pipe. |- ->-------------| *** turbo ------> to rest of intake system hose to air |- pvc or similar Basically I take a PVC cap or similar piece of plastic, drill and tap an hole, thread in a fitting to hold some line. Then that line goes to the compressor source (regulated or inline regulator). The other side can use the same coupler your intake pipe uses or a rubber one from Home Depot racing. Whatever fits and seals, varies depending on your turbo. Then you hook up the tester to the turbo and start feeding in the compressed air (regulated to ~15 psi or so). Turn on the gauges (not the car) so you can see what your boost gauge is reading. Add more air until you are pretty steady at 15 psi (or whatever max pressure you run). Then fill up a small squirt bottle with soapy water. Now trace through the entire intake system and listen and squirt for leaks. Big ones you can hear and feel with your hand. Smaller ones will be easily illuminated with the squirt bottle. Check specifically all piping connections, welds, intercooler, BOV flange and BOV itself, gaskets (BOV, TB elbow, TB, intake manifold), Throttle body shaft seals, BISS. Whereever you leak do your best to stop it. Ie new gasket, tighten connection, new BOV, reweld etc When you finally (weeks later ususally) get rid of all the known leaks test again. Then a month later test more. Basically test often and your car will be running much better.