intake "popping"

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Redlined
Fourth Gear
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Joined: Tue Apr 12, 2005 7:00 am
Location: Portland, OR

intake "popping"

Post by Redlined »

My car has been doing this for a while. and this morning it got worse.

when the engine is cold or just warm it will pop (backfire?) through the intake. This Generally happens after a quick push on the accelerator.

Normally it does it once and then power comes on and off I go.

Most often this happens coming out of a stop light onto the freeway onramp on my way to work in the mornings. On ramp is about 3 minutes from my house and is actually the point where my engine finally reaches running temp.

This morning as I was coming out of above stated stoplight the engine popped. stuttered and popped again. probably three of four times with me varying degree of gas pedal depression. Then the power came on and all was normal.

I figured it was time to find the problem and get it fixed. It is also notable that the car tends to idle roughly. I suspect a weak injector on one of the cylinders.

So... any ideas?

thanks in advance!
Dave
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1993 Legacy Sport Sedan 4EAT "Angel" *sold*
94SS_Canada
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Post by 94SS_Canada »

It could be many possible things right now, Dont worry about the more expensive stuff like injectors. Its sounds like there is a clamp loose in your intake, Check and make shure every single clamp is tight, After that if everything check out, Check out all your Vacumm hoses the main one being the BPV (i doubts it that if its at idle)

It more than likely sounds like your IACV (idle air control valve)not sealing right, or possibly the air line connected to your intake resonater (big black box with hoses on it left side of engine bay after air filter) Its the biggest line connected to it, Check it, If not follow the line to the IACV removing things as neccesary and replace the gaskets and clean it with some gas (google this)

If anyone want to add onto what i said, So someone can "confirm" thanks, Good luck!
FastRust
Redlined
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Location: Portland, OR

Post by Redlined »

Immediately after posting this i got dispatched to Idaho for a mill shutdown so haven't had time to do more than a cursory examination that found no loose clamps. ill dig a little deeper tomorrow.

However. On the 6 1/2 hour drive (each way) to Idaho and back i had time to make a few more observations.

I'm currently getting about 24 MPG (all highway driving at 65-80 mph) as opposed to the regular 19-21 MPG.

The intake would *pop* when at low RPMs with but under torque, e.g. climbing a mountain pass in 4th gear with light throttle. Dropping to third gear A) solves the problem. B) attracts the police.

Ill get a closer look tomorrow or Saturday after I've recovered from this last job.
Dave
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legacy92ej22t
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Post by legacy92ej22t »

Is it a popping or a backfire type noise?

I've seen other EJ22T's that had the backfire type thing going on and eventually #4 popped.......

Be careful, check your O2 sensor readings and make sure it's not sending a wacked out voltage reading that's making the car lean out.
-Matt

'92 SS 5mt. All go and no show. Sold :(
'94 Audi UrS4 Modded (new project)
'96 Outback 5mt.
'07 Legacy 2.5i SE

[quote="Redlined"]
Oh... and I hope the fucker get bunked with Gunter, arrested for raping Gorillas.[/quote]
Redlined
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Location: Portland, OR

Post by Redlined »

its not realy a backfire type noise its real muted but I figure it has to be firing through the intake somehow. I definately loose power when it happens.

Guy at the local parts store made a comment about some cars backfiring through the intake as the turbo was coming up on boost but I had to take a call and by the time i got off he was with another customer.
Dave
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1993 Legacy Sport Sedan 4EAT "Angel" *sold*
Redlined
Fourth Gear
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Joined: Tue Apr 12, 2005 7:00 am
Location: Portland, OR

Post by Redlined »

*facepalm* so much fuss and hastle over such an easy fix



Sparkplugs

Tossed in a new set of NGK V-powers and she seems to be running fine again.

Also tossed in my vac/boost gauge. pics to come.
Dave
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1993 Legacy Sport Sedan 4EAT "Angel" *sold*
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