I have replace fuel filter,fuelpump,egr,all injectors,coil pack,plugs,wires,cts and this car still will not idle right,engine surges up and down.At times it is getting to much gas other times it acts like it isnt getting enough gas.Also just replaced fuel pressure regulator.Can not get to the bottom of the proublem.Any suggestions?I am at wits end.
You just need to go through a simple Idle Relearn Process.
The Idle Speed Control motor will cause the accelerator pedal to tap and the car will surge back and forth, actually acting like there is a lack of power during intial startup.
Whenever a battery is changed, went dead or the ECM computer is replaced.
In order to make the engine run normal again, you need to take the car through a relearn process. Otherwise the idle could be very slow or have a 30mph idle.
To enable it to relearn, here's what to do.
1) Disconnect the battery cable for 15 minutes, before hooking it back up.
2) (KOEO) Turn the Key On with Engine Off, just so the electronics are on, but without starting the engine and turn the climate control panel to off.
3) Push the off and warmer buttons on the climate control panel at the same time and hold for up to 5 seconds for the computer to go into diagnostics.
On the fuel panel screen it will display 888 then E52 and then 70.
When it gets to 7.0 shut off the key for 1 minute.
4) Repeat step 3, two more times.
5) Start the engine without pushing on the accelerator pedal and let it run for 18 minutes with the climate control panel off.
6) After 18 minutes put your foot on the brake and shift into drive and wait 1 minute.
7) Then turn on the a/c by pushing the auto button. It needs to be warmer than 60 degrees F so the compressor can engage. Wait 1 more minute.
8) Put the shifter back in park and turn the key off.
9) Wait 1 minute
10) Idle relearn is now complete and the engine should start and run correctly.
In order to make the engine run normal again, you need to take the car through a relearn process. Otherwise the idle could be very slow or have a 30mph idle.
To enable it to relearn, here's what to do.
1) Disconnect the battery cable for 15 minutes, before hooking it back up.
2) (KOEO) Turn the Key On with Engine Off, just so the electronics are on, but without starting the engine and turn the climate control panel to off.
3) Push the off and warmer buttons on the climate control panel at the same time and hold for up to 5 seconds for the computer to go into diagnostics.
On the fuel panel screen it will display 888 then E52 and then 70.
When it gets to 7.0 shut off the key for 1 minute.
4) Repeat step 3, two more times.
5) Start the engine without pushing on the accelerator pedal and let it run for 18 minutes with the climate control panel off.
6) After 18 minutes put your foot on the brake and shift into drive and wait 1 minute.
7) Then turn on the a/c by pushing the auto button. It needs to be warmer than 60 degrees F so the compressor can engage. Wait 1 more minute.
8) Put the shifter back in park and turn the key off.
9) Wait 1 minute
10) Idle relearn is now complete and the engine should start and run correctly.
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My be the transmission discs are not changing proprerly. may need new transmission>
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Sounds like possibly the Idle speed control motor is causing a problem. There is a switch in the motor assy that tells the pcm the throttle is closed and it should take over the idle. If the switch which is nothing more than a set of points is dirty or not making good contact the pcm will order the motor to send the plunger out to accept it\'s return like the old dashpot used to on carb engines. Then pcm recognizes that throttle is actually closed and retracts. If you shift from park or reverse into gear when this is happening it will retard the timing to slow the engine down so it doesn\'t slam into gear. This continual hunting and surging and timing variation causes an erratic idle. If you are handy enough you can take the ISC apart, clean it up, re-grease with a silicone type lube and put it back into service. Otherwise, buy a new one.
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