im ready to give up

1992 CADILLAC DEVILLE
131,000 MILES • V8 • FWD • AUTOMATIC
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TEDRO
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I have a 92 deville. it starts and runs great for 20 minutes. As soon as it warms up, it gets sluggish,hesitates, and sometimes backfires through tailpipe or carb/throttle body. it will still drive if u give it a little gas the more gas u give it the more sluggish and hesitant it gets. What can it be. I have changed wires,fuel filter, rotor,dist cap,ign coil pack, and spark plugs and the problem remains.
Aug 20, 2011 at 8:41 PM
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RASMATAZ
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Do you have a check engine light?

https://www.2carpros.com/articles/engine-hesitates

Could be caused by one of the following below

Oxygen sensor.
Catalytic converter.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Knock sensor
Manifold absolute pressure sensor.
EGR Valve
Fuel pressure regulator leaking or defective fuel pump.
Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.

Note:If it doesn't apply disregard it and keep testing.
Aug 20, 2011 at 9:07 PM
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CADIEMAN
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the egr valve is on the intake.remove the valve and clean the hole out.you may have to replace it.
Aug 20, 2011 at 10:01 PM
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TEDRO
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no check engine light
Aug 21, 2011 at 4:01 AM
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FACTORYJACK
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Remove the oxygen sensor from the header pipe, roadtest it and see if the problem is still present. It sounds like the converter is plugged. As the vehicle sits, the debris falls down to the bottom of the cat, as pressure flows through it, it picks up and starts clogging. You create an airleak by removing the sensor, allowing for adequate airflow for the engine to run properly.
Aug 31, 2011 at 3:23 PM
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CADIEMAN
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youll also need to know the fuel pump pressure when you are having the problem.gm pumps overheat and just quit.later you come back it will start again for 20 min.good answer to gstacey thanks for using 2carpros
Aug 31, 2011 at 4:52 PM
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TEDRO
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no catalytic converter its staright piped for the time being
Sep 1, 2011 at 5:17 PM
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CADIEMAN
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hook up a gauge so you can see it. like through the cowl area.watch the gauge as you drive.when the probem happens we need to know the fuel pump pressure
Sep 1, 2011 at 6:15 PM