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.
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Re: 1991 cadillac deville 4.9 fuel trouble
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.
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I don't think you really understand what this fault code means, it means that likely all the engine cylinders are misfiring at random no set pattern, not any particular cylinder. I would start with checking for engine vacuum leaks like the intake manifold gasket. that is all I can say since you provided no make, model or year and engine type and size information.
Could be injectors, but I would focus on the spark plugs and coils. I'm not sure if you have a coil pack on your car, or individual coils on each spark plug. If the plugs and coils are ok, then check the injection. All your codes are the same bank, so it could possibly be your fuel rail is not getting correct pressure.
many things cause intermittently stalling if you see check engine flashing on code scan for faulty mass air flow sensor.faulty idle air control valve or egr solenoid.could have bad spark plugs and wires faulty fuel injector. contaminated fuel restricted fuel filter or fuel pump failing. faulty TCC solenoid .
Hello! when you say you checked the MAP sensor what do you mean? Did you take voltage readings at idle ? A vacuum leak is the likely culprit, especially to the MAP...The minor shake at idle being the major clue...Send a comment...guru..saailer
I had a similar problem in my grand prix i did some research and found out a couple different things that it could be... it could either be a bad fuel pump, a bad resitor, or a bad connection in the wires on the fuse box. My problem was solved simply by taking out the fuse box and checking the wire that came from the fuel system. It turned ot that it was just a bad connection.