Why does my V6 4R sometimes hesitate & stalls when accelerating from stop?
02-01-2007, 12:59 PM
#21
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It's super easy:
1) Unplug TPS (it's on the back of the throttle body, attached to the same shaft as the throttle cable)
2) Unscrew the two screws that hold the TPS to the throttle body.
3) Reverse steps to put the new one on
1) Unplug TPS (it's on the back of the throttle body, attached to the same shaft as the throttle cable)
2) Unscrew the two screws that hold the TPS to the throttle body.
3) Reverse steps to put the new one on
02-01-2007, 01:20 PM
#22
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This sort of thing happened in my brother's old Corolla, a long time ago. It hesitated badly from start and would almost stall. He would have to rev it in N and then shift it into D just to start. He changed his plug wires and the problem went right away. Maybe try the plug wires.
02-02-2007, 04:47 AM
#25
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The diagnosis for this issue of stalling or sputtering when gassing the truck is a process and not every case will have the same root cause. Since there are multiple people experiencing similar problems it may be hard to help everyone at once in the same thread, but my comments on the TPS were regarding the initial question about goosing it and then stalling.
The TPS is just one part to check but it is a common problem and can be quickly eliminated (just probe resistance with a DMM and then have someone move the gas pedal, resistance should change linearly....if not, or you get spikes, the TPS is bad). Other areas to check are the IAC (idle air conrol valve) which controls the idle speed (there is no adjustment idle screw on a 3.4L engine). That should be disassembled and cleaned thoroughly along with the throttle body. Next you should be checking fuel pressure on the line at idle and at speed. There are a few problems which can occur such as a bad FPR (fuel pressure regulator), lagging fuel pump or clogged fuel filter, so have that checked as well. Then you should look at any items that were recently replaced (plugs, etc) since there may be a defective part that got installed. If you still have issues you may need to hook up an OBD computer to view the sensor outputs, timing, fuel trims, etc to get further clues as to where your problem lies.
The TPS is just one part to check but it is a common problem and can be quickly eliminated (just probe resistance with a DMM and then have someone move the gas pedal, resistance should change linearly....if not, or you get spikes, the TPS is bad). Other areas to check are the IAC (idle air conrol valve) which controls the idle speed (there is no adjustment idle screw on a 3.4L engine). That should be disassembled and cleaned thoroughly along with the throttle body. Next you should be checking fuel pressure on the line at idle and at speed. There are a few problems which can occur such as a bad FPR (fuel pressure regulator), lagging fuel pump or clogged fuel filter, so have that checked as well. Then you should look at any items that were recently replaced (plugs, etc) since there may be a defective part that got installed. If you still have issues you may need to hook up an OBD computer to view the sensor outputs, timing, fuel trims, etc to get further clues as to where your problem lies.
Last edited by MTL_4runner; 02-02-2007 at 04:49 AM.
02-03-2007, 01:15 PM
#26
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OK, so when I took it in today they said my idle valve was bad. The part and the gasket was $266. All told $450.24 added to my previous $585.06 for a grand total of $1,035.30. All for some hesitations and 3 stall outs. My butt really hurts. At least the first round of things needed to be done anyways (cleaned MAF, checked induction for leaks, reset fuel trims, oil change, drive belts, injection service, transmission flush, replace fuel filter). I hope that fixes it!!
Last edited by jgs9455; 02-03-2007 at 01:17 PM.
06-28-2018, 06:23 PM
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Solved?
OK, so when I took it in today they said my idle valve was bad. The part and the gasket was $266. All told $450.24 added to my previous $585.06 for a grand total of $1,035.30. All for some hesitations and 3 stall outs. My butt really hurts. At least the first round of things needed to be done anyways (cleaned MAF, checked induction for leaks, reset fuel trims, oil change, drive belts, injection service, transmission flush, replace fuel filter). I hope that fixes it!!
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