Bad-A-SS

iTrader: (3)

Ok guys, I was just driving my car and decided to get on it a little and run my buddy. Well whenever we went to turn on to another road I decided to get on it again but this time my car bogged down and I let off which resulted in a pretty loud backfire. From then on it doesnt feel right. Also, I observed that the deceling boost is now around -24.1 compared to a -23.0 and that idle boost is not about -19.1 instead of -17 to -18. Also it shows 0.3 to 1.0 knock retard. Help me guys please

blueLNFftw

iTrader: (16)

what the hell are deceling and idle boost???


its called vacuum bro.


your **** is broke.
open the hood and explore.

Chevycobaltss3

iTrader: (2)

If you were on it when it happened, you can have blown a lash adjuster, got a vacuum/boost leak, somthing hit the maf and caused the cars to skew. Also check compression!

Tjolley

i see another build thread in the future..lol
something happened wen i cracked a piston..

Bad-A-SS

iTrader: (3)

Ok well you know what im talking about I couldnt think of the word lol but there is not ticking or anything like that. No smoke either

Tjolley

my car ran fine with 2 cracked pistons..no smoke or anything...i noticed alot more air coming out of the breather hose..

Bad-A-SS

iTrader: (3)

Would a fouled plug or bad gas cause this to happen too? jw

Chevycobaltss3

iTrader: (2)

Yes

Bad-A-SS

iTrader: (3)

Thats what I hope it is I will get some pics of the plugs.

Bad-A-SS

iTrader: (3)

Ok guys here are the spark plugs. Not sure what I am looking for help me out.

uv blue

I just swapped my plugs last week and they looked way worse than yours and my car still ran fine so i dont think thats your problem

Bad-A-SS

iTrader: (3)

Alrighty then on to the next thing I guess

Bad-A-SS

iTrader: (3)

Just saw there there is a little oil where the spark plugs goes in number 1 going from left to right. What might cause this?

buildmeanempire

iTrader: (5)

Just going out on a limb with this but my other car had oil in with the spark plugs, it was the valve cover gaskets that go with the spark plugs. Maybe someone else can confirm this. As for everything else... don't know.

Bad-A-SS

iTrader: (3)

I have a feeling its the by pass valve just bc of how the vacuum n boost are acting.

Bad-A-SS

iTrader: (3)

Also would a clogged cat or just burntout cat mess with the vaccum and boost? Also would it cause it to run richer or leaner, thus causing knock?

jp1600

iTrader: (2)

Have u tried just replacing the plugs? Looks like ur about due to do that, see if it fixes it

mrbelvedere

iTrader: (3)

anything below zero is vaccum anything above zero is boost do you still have a cat if so i would look there first and do a comp test if 1cyl is showing higher then the rest then chances are you have a collapsed lash adj on the exh side

Bad-A-SS

iTrader: (3)

So how to I do a compression test?

user 72239

iTrader: (4)

Buy a compression tester. you can get em pretty cheap at parts stores or even rent them.


How To Do an Engine Compression Test - Compression Testing Your Engine - Testing Engine Compression

Bad-A-SS

iTrader: (3)

What kind of numbers should I be seeing?

user 72239

iTrader: (4)

Well there are a few different variables.

Since im in Colorado, my altitude was 5800 ft and I saw 125 psi across the board.

Some say between 125 and 180 is good. Anything below 100 is bad.

As long as all 4 pistons read the same, or close, you should be good

mrbelvedere

iTrader: (3)

180 to 210 is what they normaly run

Bad-A-SS

iTrader: (3)

Ok I will remember that and I know it was stupid for me to do, but I found out it only will boost 12psi instead of the normal 15psi I see. I figured it would help determine what is happening. Also, it is only knocking maybe one time when I drive it. Could the ECU have some how gotten messed up and I need another tune or what guys this is driving me INSANE

mrbelvedere

iTrader: (3)

it could be the winter blend fuel causing the knock do comp test and a leak doown test where is hickory