marlboroman71818

ok so its pulling about 8" of vacuum all the time at idle. no fluctuations, no spiking and no idle or drivability problems. plugs look great, not using any oil, not blowing anything out of the dipstick either and no intake leaks. the vacuum has been verified with logs but doesnt seem to affect anything that i know of (not sure about power). what gives?

Mangled03gmc

iTrader: (95)

Wow that is strange.. Has it affected anything at all with the truck??

marlboroman71818

not one single thing! lol i dont know what to think. it has been this way now for about a year or more

Mangled03gmc

iTrader: (95)

Roll with it lol.. I'm guessing its one of them ''if it isn't broke don't fix it'' things.. I mean wth can you do if it is running the way it should

03sierraslt

iTrader: (22)

Thats with a stock cam? Ever do a leak down test?

marlboroman71818

yeah thats what ive been doing but its got me wondering wtf, and I hate when I cant figure something out lol

yep stock cam, correct me if im wrong but is there any reason to do a leak down if i am not having any vacuum fluctuations, no loss power, plugs look perfect, no change in idle and operating quality? I would think that if I had that big of a problem it would show up in one of those things?

03sierraslt

iTrader: (22)

I agree to one extent however something is not right for your vac to be that low. How are your breaks? What MAP is it idling at?

Atomic

iTrader: (42)

thats around 77kpa, right?

does it go up a couple when you put it in drive while ideling?

budhayes3

iTrader: (19)

Could there be something wrong with the gauge? Maybe test that...try another known good gauge in it's place. You should have at least 17 mmhg with the factory cam at idle btw...

marlboroman71818

Breaks are great, the MAP is around 6-8"
yep it gains like 1-2" vacuum

I wish lol, that would make this much easier. It has been verified with the MAP sensor reading on HPTuners