Backfiring when accelerating

2004 NISSAN URVAN
300,000 MILES • 4 CYL • 2WD • AUTOMATIC
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DUMISANI NDABAZAKE NUKA
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I have a Nissan Caravan with a ka20 engine. the camshaft dowel got damaged and it mis timed. I have replaced the camshaft but it is backfiring when you accelerate, but the timing is correct and when I close the fuel return pipe it stops backfiring. So what can be the problem?
Sep 11, 2020 at 9:33 PM
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KASEKENNY
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By plugging the fuel return we are most likely decreasing the fuel pressure. So we need to start with checking the fuel pressure. Clearly with a recent timing repair that would be the likely cause. However, if blocking the fuel return causes it to stop then that points us to the fuel pressure.

Here are a number of guides that will help with all of this. Let's run these down and go from there. Thanks

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

https://www.2carpros.com/articles/engine-backfires-while-running

https://youtu.be/HiI_eeFg-2A
Sep 12, 2020 at 3:39 PM
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DUMISANI NDABAZAKE NUKA
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I have tried all these guides but i still have the same problem?
Sep 13, 2020 at 1:13 PM
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KASEKENNY
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Were you able to get the fuel pressure? If so, was it steady while it was running and backfiring? What was the PSI?
Sep 13, 2020 at 7:56 PM