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01-23-2020, 06:10 PM | #41 | |
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Re: Question on loosing fuel pressure going down track.
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01-23-2020, 07:48 PM | #42 |
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Re: Question on loosing fuel pressure going down track.
A lean miss-fire will show a rich condition due the un-burned fuel leaving the combustion chamber.
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01-23-2020, 08:09 PM | #43 | |
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Re: Question on loosing fuel pressure going down track.
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A severely rich mixture will also show as a lean condition on a wideband sensor. Spark plugs and header tubes don't lie.................. But the widebands can. |
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01-23-2020, 09:59 PM | #44 | |
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Re: Question on loosing fuel pressure going down track.
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Misfires do look lean.
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Ed Wright 4156 SS/JA Last edited by Ed Wright; 01-23-2020 at 10:02 PM. Reason: Can’t type |
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01-24-2020, 01:51 AM | #45 |
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Re: Question on loosing fuel pressure going down track.
YES, a mis-fire will show lean on a wideband sensor. All that sensor reads is oxygen, when there's a mis-fire, oxygen isn't getting used on that cycle so it passes through the engine un-used. A wideband sensor in a collector is seeing the average of 4 cylinders. If say theres a distribution problem in an intake manifold, the average of the 4 could show close to perfect, but with the bad intake it may have a severely lean hole. The better way to check would be to weld 8 bungs into the primary tubes of the headers and either install 8 sensors or rotate 1 sensor over 8 passes down the track.
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01-24-2020, 10:10 AM | #46 |
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Re: Question on loosing fuel pressure going down track.
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01-24-2020, 11:41 AM | #47 | |
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Re: Question on loosing fuel pressure going down track.
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The too rich showing lean though, that can be tricky to diagnose. A N/A engine will typically be falling on it's face though, but on a forced induction it can be misleading, therefore plugs and collectors are the best thing to determine the root cause. |
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01-24-2020, 12:11 PM | #48 |
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Re: Question on loosing fuel pressure going down track.
On my other car I use a 2 step and car goes rich staging with trans brake and 2 step. Takes about 1.5 seconds to clear up when released.
Maybe 2 types of misfires. One with plug not firing and car goes rich , the other if injected and injector does open then car goes lean? IDK Last edited by Jeff Stout; 01-24-2020 at 12:13 PM. Reason: more |
01-25-2020, 01:24 PM | #49 | |
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Re: Question on loosing fuel pressure going down track.
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Just remember, a wideband sensor only measures oxygen inside the exhaust system, it knows nothing about fuel inside the pipe. |
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01-25-2020, 03:21 PM | #50 |
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Re: Question on loosing fuel pressure going down track.
Ok here is the fix. I bypassed summit inline filter and changed vent line on fuel cell. 1 gallon in about 40 seconds and today's pass with leaner secondary rods im at 5psi in high and went 12.1 afr. May night be perfect but improved .3 mph
I want to thank everyone for the suggestions as they were helpful in chasing problem. Last edited by Jeff Stout; 01-25-2020 at 03:24 PM. Reason: More |
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