Big backfire and boost creep.

[crimsonGST]

So I replaced the PCV valve on my car as well as the hose coming off of it, and the car ran much better than what it had been running. A local mechanic helped me track down that problem. Now I have a new one, I'm experiencing a little boost creep (between 12-15psi with no MBC) and also when it peaks on the boost, if it try to keep it WOT the car backfires BIG TIME! Any suggestions before I start tearing into it tomorrow morning?

 

[Bud92gsx]

What kind of backfire buddy?

 

[SnowBird]

Spiking so hard causing fuel cut? I would think you could handle 15psi unless you caused a boost leak with the pcv valve.

 

[crimsonGST]

PCV valve is fine. Hose coming off of it is fine. No leaks that I can hear or feel. But it's not even a big spike and then a backfire. It's like I'm driving, I hit boost, it starts to go up, BACKFIRE, keeps going, BACKFIRE, and by this time I've let off.

EDIT: The mechanic that has been helping me said to clean my plugs, could this be what is making it do this?

 

[crimsonGST]

So quick update, just clean the plugs, and the car ran alot better. In 4th though it still hit 15 and had a little backfire. It stayed pretty steady between 10-13psi in all other gears. I think I'm going to drain the gas because it was 87 (I know, but due to Hurricane Ike it was all they had) and put some 93 in. Hopefully that will solve my problem. Any thoughts?

 

[Bud92gsx]

How much gas is in there yet? What kind of plugs do you have? How new are your wires?

 

[xsboost]

Switching from that 87 should help (at least with knock and ecu timing pull). If cleaning your plugs seemed to help, try new plugs and wires. Good luck. When you find the problem be sure to let us all know.

 

[grantman10]

My car was, and still is having this same problem.

I installed a SSAC FMIC kit on my car and it turns out the flanges were warped on the bov and TB. This of course caused a huge boost leak. I had them resurfaced and that caused my car to backfire like this a lot less.

It still does it from time to time, but i still think i have some leaks. Although this does not sound like he notorious "brick wall" that is fuel cut, i think it is a more mild version of fuel cut...

 

[crimsonGST]

Switching from that 87 should help (at least with knock and ecu timing pull). If cleaning your plugs seemed to help, try new plugs and wires. Good luck. When you find the problem be sure to let us all know.

Plugs and wires and brand new, the only reason I cleaned them is because I pulled the one closest to the PCV valve and it was super thick with carbon buildup from the oil due to the bad hose.

 

[grantman10]

Crimson, when was the last time you did a boost leak test?

 

[crimsonGST]

Right after I changed the PCV valve.