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Doriansrjeep93
02-07-2015, 02:17 PM
So I'm having a problem with my motor surging randomly. Sometimes it does it at idle or under a load, the surge is like the power dips and it kinda makes the motor die but only for a second then jumps back up to idle and lunge's forward. Its getting worse by the day but its still randomly doing it and not all the time. Does anyone have any ideas????
4.3LXJ
02-07-2015, 06:50 PM
Only at idling rpms?
Doriansrjeep93
02-07-2015, 07:37 PM
No. It does it under load and at idle. The only time it doesn't is when I'm to the floor.
4.3LXJ
02-07-2015, 08:01 PM
How long since you changed O2 sensors and do you have any indications of a vacuum leak?
Doriansrjeep93
02-07-2015, 08:34 PM
No vac leak. And i haven't seen a o2 sensor on any of the exhaust and i have checked every pipe. Someone said it might be an ignition problem just don't want to spend the money for a tune up if I don't need one.
4.3LXJ
02-07-2015, 08:50 PM
If you don't have an O2 sensor right before the cat, you need one. This could explain what is happening. The O2 sensor gives information to the PCM to determine the proper fuel/air mixture. If it has no information, it is taking a shot in the dark on this. When you mash the pedal to the floor, then the PCM bypasses this method and determines its own maximum power ratio, explaining why you can stop it with doing that
Cheromaniac
02-08-2015, 09:30 AM
So I'm having a problem with my motor surging randomly. Sometimes it does it at idle or under a load, the surge is like the power dips and it kinda makes the motor die but only for a second then jumps back up to idle and lunge's forward. Its getting worse by the day but its still randomly doing it and not all the time. Does anyone have any ideas????

The most likely cause of your symptoms is the throttle position sensor (TPS). The problem could either be with the sensor itself or with the wiring harness connector. At this time of the year with cold damp weather, TPS problems are quite common.
Check the connector and the pins inside the TPS for any dirt or moisture. Clean thoroughly with contact cleaner and apply dielectric grease. See if that solves the problem. If it persists, check the voltage in the middle of the three wires coming from the TPS with the ignition on and engine off. The voltage should ramp up steadily from about 0.7v (closed) to 4.3v (fully open) as you gradually open the throttle blade. Any dips or spikes will indicate a bad TPS.