Vacuum questions. HELP!

[MysterE30]

Hey everyone. so i want to test for some vacuum leaks. does anyone know where to find what each hoses are suppose to be set at? i have the tester but i couldnt find anything in the bentley about it. if anyone knows for some reason or knows where i can find out please let me know. thank you


-Tony

[MrSpectre]

there are only vaccum lines for the ICV and brake booster on the M20

[jlevie]

The best way to check for intake leaks is to have a smoke test run on the intake. If not that, then remove each hose that attaches to the intake and replace any that have cracks. Which will probably be every hose. Also replace the dispstick o-rings and the oil filler cap seal. Then with the engine idling, spray carb cleaner around all edges of the intake manifold gaskets and around the injector seals. If there's a leak at any of those point the engine speed will change when you hit the leak with carb cleaner.

[MysterE30]

good to know good to know. thanks levie ill be checking these things this weekend.


anything else i should look for?

[jlevie]

I failed to mention the evap control system or brake booster as a possible intake leak. You'll want to check the valve to see that it is closed when not powered. The brake booster can be checked with a vacuum pump.

[twright]

Don't forget the o'rings on the oil return tube! (They caused my Check Engine light to come on at idle.)

[MysterE30]

sweet thanks for all the info gents. much work and testing going into this beast.