Backfiring

[David Sutton]

Well.. this has been long delayed.
SO basically, when it's cold, my boost creeps. Anytime it reachs 19 -20 psi my car backfires wildly. I DONT KNOW WHAT THE PROBLEM IS. I've leaned it out, richened it up.. nothing works. I tried to log my car tonight, but the cable said hooked up improperly (that's another story). But anyways, on my way home tonight, 5 minutes from home, I was cruising in 5th on the highway. My car felt really bumpy, like as if a wheel was loose. So I slowed down, and it wasn't a loose tire ,it was my car repeatedly backfiring in small amounts, shaking my car horribly. When I stopped it stalled, or came very close to (fighting to keep the revs up). I checked for any audible / visible leaks in common places, like the IC piping, intake etc. Found nothing. My car used to get this way when an IC coupling would blow off. About 5 minutes later.. it's fine again. WTF. Now when I was driving home, I boosted a few times, and it would backfire like crazy, usually only under boost. I would get normal power, then suddenly *BAP**BAP*, and I'd get complete power loss. But it wouldn't stall even if i just put in the clutch while driving. I was thinking, maybe spark plugs and wires? ANY SUGGESTIONS?! PLEASE I'M DYING HERE...  :cry:

[John Novo]

Dave, what are you up to this Friday evening or Sat?

If you're into it, we could hook up my Pocketlogger and see what's up.

Oh, did you make note of the settings on the SAFC before you started dialing it?

Later.

[David Sutton]

Yea I have everything written down.. and sure, Friday would be awesome.
PM me you rcell number or something.. or add me to MSN messenger if you have it. Thanks man.

- Dave

[Martin Raska]

Is your timing correct?  And I wouldnt boost 20 psi if I couldn't tune it right or it's still cold.  There is a point where I would highly recommend against the change settings and listen/smell the exhaust method.

[Chris Andrews]

Anytime it reachs 19 -20 psi my car backfires wildly.

So it doesn't backfire at 18 psi, 17 psi or 16 psi?

I would say you have an intake leak that happens at 19 psi.  Stock BOV?

It might be wise to fix your boost creep before you blow up your engine.  20 psi on pump gas is running the ragged edge.......

[David Sutton]

Yea I know. It seems to be happening at anything over 14 psi now. Yea I'm thinking it's an intake leak that is triggered over a certain psi. But if it was leaking, would it not vent back into intake normally? I have a greddy type-s vented back into the intake. Hmmm.. It backfired so loud on my way home it actually sounded like a gunshot. It hit me in the chest!




**UPDATE**


OMG... So. I was beggining to want to kill myself with the car problems and all. CHanged the plugs.. nothing. Checked everything I could possibly think of. I then noticed my Air filter on the end of my 2G maf was really loose. It just slipped off, the clamp was almost off. Guess what I found. The piece of metallic honeycomb that the sensor uses was tilted sideways and blocking the hole, allowing maybe 10% of the air it normally would into the intake to the turbo. My god. So I put that back to normal, and guess what! It's pulling the hardest since I've bought it, at 17 psi! It's 100 times faster than when I got it tuned at Kinetic even. This problem has been going on for a long time too.. so basically, this could've been like this , although less noticeable, since I bought the car.. my god.. LOL

[Jesse Veitch]

think of all that time wasted when you could have been going so much faster  :twisted:

at least it didn't get sucked into your turbo though

[John Hartman]

that would explain alot of your drivability problems.  

Holy, imagine if you WOULD have sold it, and cheap because you were frustrated and figured it was gonna be big bucks to fix it?  Then some guy puts the honeycomb back in and BAMM!!  tons more power, no issues etc?

[David Sutton]

John, that's what suicide is for.
Jusssst kidding. But seriously, I'd be damn close. :|

[Danny Bouliane]

glad to hear you got it sorted out...

now lets figure out why we can't log your car.