Hey everyone I'm looking for some help. For the last few days my car has been running with more vacum than normal. As much as 20+ psi while cruising and it seems to have lost a little power. And it has been backfiring a little. I don't think it is holding boost as well either. A vacum leak would create low vacum right? I'm stumped so if anyone has any ideas, thanks in advance.

 

Just off the top of my head:

Increased vacuum could be from a restriction in the intake or a change in cam timing.

Loss of power could be from either of the above, plus a lot of others.

Backfiring could be from either a rich condition (like an airflow restriction after the MAF) or from a change in cam timing, or many other things.

I would look first at the hose between the airbox and the turbo inlet first, and pray that something is narrowing it. Other things could get expensive. And they'd be way out of my league.

 

Isn't 20+ psi, boosting?

 

yea i think he meant 20 inches.

 

sorry everyone I did mean 20 inches not psi. I was in a bit of a panic when I posted. I go crazy when I think something is wrong with my car I'm sure everyone can relate!

 

Check your lines...What mods do you have?

 

I usually show 19-21in of vacuum at idle and a few less with AC on. I have intake/exhaust/dynoflash/ground kit/MBC@20psi

 

Hi,

What is your vacuum at idle? Isn't it better to have a higher # for vacuum at idle (for example 20 is better than 18) since it means the engine has good compression?

My car with a Defi mech boost gauge reads just about 20 inches at idle and can go to almost 30 while cruising/downshifting...

Thoughts?

FB

 

my vacuum reads usually about 16 inches or sometimes 17 at idle. with a/c on it can drop to 14 or 15. when downshifting it usually goes to 30 inches. jason

 

Thanks to everyone for helping out, I also checked with mitsu for specs and 18-20 inc at idle is perfect. I think my car was just having a bad day and I made to much of it. Thanks for your replies.

 

Thnx for the info phish52. I feel good knowing Im withing spec.

BTW I LoVe Rockin' out to PhIsH, too bad they stopped touring =(

 

I see about 12ish at idle.

 

Where are you located? I was in Cali and I was at 20 inches. Now I came back home to New Mexico and my idle is at 14 inches. My idle runs like crap.