Hello this is my first time posting didn't really know too much about this site but would appreciate any help or feedback I can get I basically have a brand new ZR2 was about 30,000 miles on it 99 Blazer I bought it new back in 99 needless to say I needed it for work purposes because it's A 3 hour round trip from my house to where I'm working at right now and it's way cheaper on gas than my F-150 so I got out and drove it and it was fine for the summer months winter months came up 4 by 4 wouldn't kick in well I have vacuum issues so I replaced all the vacuum lines and they basically rebuilt everything from the cable to the vacuum to the switch so my issue is I have a mass air flow sensor that keeps on giving me check engine light I replaced it once now with a brand new one from AutoZone and I'm still getting that like the other issue is I'm trying to figure out where the PSI supposed to be in my vacuum so I hook it up to my OBD2 reader and it's saying I'm not about 19 at idle but when I goofy it drops down for Split Second .07 and then jumps back to 26 27 and then back at idle at 19 my issue is I read on line that is saying I have bad Rings If it drops down to .07 at all so I'm just wondering that could it be I mean I've got thirty thousand miles on it I've owned it since new

 

First take a look at the bottom right portion of your keyboard or phone screen there you will see a key that has a dot it is called a period when used to end a sentence so that people can read your post without trying to spend a lot of time trying to make sense of your post using basic punctuation is not only a courtesy in general but especially to people you are asking for help and will probably result in a better chance of getting assistance I don't think there are many that will take the time to go thru a post several times trying to figure out where you meant to end your sentences it is also a good idea in general to reread your post looking for words that your spellcheck changed on you we all hate that but it happens this also helps the reader understand clearly your symptoms instead of the reader having to try and translate the words that you really meant that the spellcheck feature changed on you we all understand being frustrated trying to fix our issues and are jumping on the phone to try and post for some help but if we take a step and take the time to draft a post that can be understood it could result in a quicker response that will help us just my two cents best of luck and I with all sincerity hope someone here can help you out

 

Owe! My Head!

All I got was a Vacuum issue and a MAF issue..

For the MAF , clean the heck out of the MAF connector using electronic cleaning spray(eg- CRC) and make sure there's no breaks in the wire or connector.

Vacuum is measured in Hg , not PSI. Best to get a Vacuum gauge and measure it at , or right before the check valve , then start measuring other segments.

Best of luck to ya...

 

where is your periods? Lol.......

 

While we're on the subject of grammar, it's where 'are' your periods. Sorry, I had to.

If you're concerned about having bad rings, I would recommend doing a compression test. Other than vacuumn, are there any other reasons you suspect bad rings? Are you burning oil or anything? In my experience rings aren't one of the common things to go wrong in a 4.3

 

heheheh....

 

It is perfectly normal for vacuum to dramatically drop when you stomp the little pedal then bounce back a tad high then return to normal.
That's what I understood this to say: