Manifold backfires?

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douglas vincent
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Manifold backfires?

Post by douglas vincent »

So I am getting a manifold backfire which blow off my while intake. This only happens when I am boosting 8-10 psi. Could this be because my ABV/BOV isnt working correctly/enough?
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1990 wagon, EJ25 12.3 @ 116.5 FAST Family wagon getting new motor soon
1992 wagon, wifes daily, high compression
1992 Touring wagon, should I keep it?
BAC5.2
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Post by BAC5.2 »

Probably not.

What is the valve timing of the N/A cams? Your intake valves might be open a little to long.
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legacy92ej22t
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Post by legacy92ej22t »

That is not good Doug. You might be getting some preignition detonation.
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douglas vincent
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Post by douglas vincent »

I think it might have been the BOV, or lack of. The long tube leading from the BOV back to the intake was pinched off. So the huge pressure spike might have been setting off the backfire. This never happened at lower than 8 psi, but also at those stages I was either leaking boost, or actually had the BOV working correctly.

Havent had a problem since I fixed the pinched line.
Reddevil, Awaiting new heart, will it ever happen?
1990 wagon, EJ25 12.3 @ 116.5 FAST Family wagon getting new motor soon
1992 wagon, wifes daily, high compression
1992 Touring wagon, should I keep it?
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