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Engine stumbling HELP!

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Old Aug 30, 2021 | 05:56 PM
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Default Engine stumbling HELP!

I have a 2000 Trans Am LQ4 engine, Tick polluter cam, Long tubes with 3" dual exhaust,Fast 102 intake, Nick Williams 102 TB, These were upgraded in order to find lost boost. The intake was not the problem. Aero Motive 340 pump, Aero Motive fuel pressure regulator, and a D1SC with 10 lbs of boost. It will crank and idle but stumbles bad and misses when slowly giving it gas up to 2000 rpm if i mash the gas fast it will rev. I have installed new NGK BR7EF plugs gapped at .030. New AC Delco plug wires. New AC Delco 02 Sensors, New car quest crank sensor. I have changed out the IAC and the TPS with ones that I had on my 2000 Silverado that are working fine. They are the same part # also.Fuel pressure 58 PSI. I also change out the ECM with the first one that was in the car. The engine and build has less than 500 miles. Compression check is good. Could it be a ground or the cam position sensor? Also it was running strong until I broke a blower belt.
Thanks!
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Old Aug 30, 2021 | 08:42 PM
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Do you still have a MAF? If so you may try unplugging it while running and see if it runs better when unplugged.
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Old Aug 30, 2021 | 09:35 PM
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Originally Posted by eTXOne
Do you still have a MAF? If so you may try unplugging it while running and see if it runs better when unplugged.
sorry I forgot to tell you that I have a speed density tune. So I no longer have the mass airflow
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Old Aug 31, 2021 | 04:16 PM
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There's a forum for help with this type of issue[s].
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Old Aug 31, 2021 | 05:52 PM
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Default Lean missfire OR Black smoke ?

When at 2000 RPM, do you see "black smoke" in the exhaust tips OR the sent of high HC ?
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Old Aug 31, 2021 | 10:31 PM
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I'm not seeing black smoke. Not sure what HC is?
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Old Aug 31, 2021 | 10:59 PM
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Default HC = Hydro Carbons

Hi, Hydro Carbons are unburned fuel created when the engine is too lean, a strong sent and this gas will also "burn" your eyes.
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Old Sep 1, 2021 | 08:25 AM
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you need to datalog it.
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Old Sep 1, 2021 | 11:54 AM
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I agree but I have no experience doing this? Anyone close to Lexington NC that can help?
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Old Sep 9, 2021 | 08:32 AM
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I had a similar problem once and one of my injectors was dumping to much fuel at idle but when i revved mis went away.Not saying that is your problem but something to look at. I found the injector by pulling rail and putting 58 psi on it and found the injector that was leaking down.
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Old Sep 10, 2021 | 02:08 PM
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Thanks for the help! I also like your truck. I have a 2000 SBSD Silverado that I'm working on.
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Old Sep 21, 2021 | 09:47 AM
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Thanks. Any luck with your troubleshooting?
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