There can be a misfire too from the cylinders.
An engine that
hesitates, stumbles or misfires when accelerating or when
it is under load is an engine that is either sucking too much air, not
getting enough fuel or misfiring. If the Check Engine Light comes on,
you may find any of the following codes:
• P0171, P0174 Lean
fuel condition codes
• P0120 to P0124 Throttle position sensor codes
•
P0222 to P0229 Throttle position sensor codes
• P0400 to P0409 EGR
related codes
If there are no misfire codes, a common cause of
acceleration stumble is a bad throttle position sensor (TPS). The TPS
tells the computer how far the throttle is open. The computer uses this
information to determine how much fuel is needed to maintain the correct
air/fuel mixture and when extra fuel is needed if the throttle suddenly
opens wide.
Another common cause is dirty fuel injectors. If
varnish deposits have built up in the tips of the injectors, they won’t
spray as much fuel as they normally do, or will “dribble” fuel instead
of spraying a fine mist. This creates a lean fuel mixture and
conditions that are ripe for stumble and hesitation (also misfire). Look
at short term fuel trim (STFT) and long term fuel trim (LTFT) with your
scantool.
If the numbers are high, it tells you the engine is running lean and
the injectors need cleaning. Treat mild cases with a high quality
fuel-injector cleaner additive. Severe cases require professional
cleaning equipment.
Also if this sensors apply to your
vehicle, camshaft sensor or
crankshaft sensor if sensors bad you don't get any spark. Also
run a scan on the car.
Good
luck and rate this solution,
please.
The PCM is causing one of the injectors to not fire when loaded.
The ECU is feeding the PCM wrong data, also the PCM is misadjusting the
mixure.
Check the following:- MAP/MAF or Fuel Pressure Regulator
O2 sensor
Throttle Positioning Sensor or Coolant Temperature Sensor
Good luck
The PCM is causing one of the injectors to not fire when loaded.
The
ECU is feeding the PCM wrong data, also the PCM is misadjusting the
mixure.
Check the following:- MAP/MAF or Fuel Pressure Regulator
O2
sensor
Throttle Positioning Sensor or Coolant Temperature Sensor
It does not mean that there should be any codes.
Good
luck
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With all due respect sir, I clearly stated a transmission issue. The transmission cannot misfire. Go back and read my problem again, and then think about what is going on in the transmission. The engine does NOT misfire, nor does it do ANYTHING it should not. In park, going down a hill, or coasting the entire thing runs as smooth as silk. Hard take-off, hard vibration. Easy take-off little vibration. It fibrates, but ONLY under a load. Bigger the load, the harder the vibration. The engine runs smooth at all times... (UNLESS the PCM is causing one of the injectors to not fire when loaded, or if the ECU is feeding the PCM wrong data, or if the PCM is misadjusting the mixure (due to bad MAP/MAF or Fuel Pressure Regulator, O2 sensor, Throttle Positioning Sensor or Coolant Temperature Sensor) when addional fuel is required by the engine to provide sufficient power under loads. NONE of these are the case. Rather, it seems to be in the tranny, AND I believe it to be the TC, but I cannot know for sure as I am not the transmission guy to go to when the problem is this illusive.
There are NO codes...
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