Chevy C1500, 5.0 V8--Engine will start but will not idle or run at speed unless the throttle is manipulated. Engine runs rough and has very poor acceleration when trying to increase speed.Engine does not backfire at any RPM. No Check Engine Light. TPS--good MAP--good IAC--good ECM--? Injector(s)--? Thanks

Throttle position sensor or maf sensor malfunction.

Engine Runs Rough, Stalls, Hesitates on Acceleration, Hard ...

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Ford Probe Engine Runs Rough, Stalls, Hesitates on Acceleration, Hard Starting, Poor Performance. This is a verified problem based on 9 reports. Learn more ...

Starting Problems - 1997 Ford Probe - RepairPal

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Dec 5, 2010 - Starting Problems on 1997 Ford Probe ... If the engine runs rough,stalls, hesitates on acceleration, is hard to start, or has generally poor ...

A new misfire/hesitation on accel. Problem.. - ProbeTalk.com Forums

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I'm not sure what you mean by "under load", maybe with a/c on, etc. Also is it really an engine misfire or a rough idle. If it really is a misfire, a scantool at your local parts store should be able to read a code for that. Sometimes a rough idle could be due to just a cracked or disconnected vacuum hose or dirty throttle body. You didn't say whether it runs ok at highway speeds. Sometimes a rough idle can be cleared up a lot with throttle body service or injector flush. Sorry, this is the best I can do with information provided.

The truck ECM computer controls the idle speed based on a number of engine parameters. Idle drops to a minimum preset level when engine coolant reaches normal operating range and the engine goes into closed loop control. This idle is typically set at around 575 rpm, and cannot be changed without reprogramming the ECM. The miss is not caused by the idle speed - unless the engine is tuned properly and has not lost compression, this idle speed can result in a rough running engine at idle (typical with older 4.3L Vortec engines). Best bet is to get a complete tuneup which will include checking the O2 sensors, catalytic converter and cleaning the IAC valve and throttle body.

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve but always run a OBD2 fault code as well as the cleaning procedure. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control

Do the following service it should help the stall out.

Engine stalling and rough run issue at low speeds

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control

yea id definately try cleaning ur throttle body 1st. My 03 1500hd had the exact same bad idle after my battery went bad it would die at lights unless i kept foot on gas i cleaned throttle body runs perfect now took 30min cost 8$ for cleaner at autozone and theres how to videos on you tube

Possible Idle air control, simple to change on the throttle body

SOUND LIKE YOU MISSING THE IDLE SPEED SOLENOID.I REMEMBER I HAD A 81 OLDS 260 V8.IT HAD THE 2 BARREL ROCHESTER.IT HAD THE IDLE SPEED SOLENOID MAKING CONTACT TO THE THROTTLE LEVER.