Unable to pressure test intake system ?

[Wildman95GS-T]

My car is running a little rough and i get only 16in hg on my vdo boost gauge at idle, so i thought that it might have a vacuum leak someware in my intake system. I made a simple test fixture (4" of 2 1/2" hose, pvc cap, valve stem and clamps) to pressurize my system, hooked it up and plugged off my mbc, i first tried to use a hand pump but could not get any pressure built up, i then went to a small electric air pump and still could only get about 4psi of pressure to build up. I cannot hear any hear any leaks, not sure what i am doing wrong or why i cannot build up pressure

 

[infinty99]

Recently had simular problem.

I had to go witha bigger air source to locate the leak. It was starting to leak abour 3-4 lbs PSI and a small pump just couldnt get higher than that. Since it was starting to leak at that pressure.

Once I stepped to bigger pump and got my pressure up I was able to find the leak.

 

[logans dad]

i have a regulator on my air compressor and set it at 20 then 25 to check for leaks. do u have a friend that has a compressor with regulator. all regulatoes are differant so maybe start at 15 then go up if thats not giving u enough pressure.then spray every thing with soapy water. I also have a air nozzle that locks on. just makes it all easier to check for leaks.

 

[Wildman95GS-T]

Thanks, i have an air compressor, just need to get a regulator. I was afraid to use that much air source since in the instructions on how to build a tester stated using a hand pump. One quick question, should i do the test with the car warmed up to operation temp or let everything cool down so you don't burn the crap out of yourself