Feels like a misfire

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Sep 29, 2008 | 11:59 PM

lzrj

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Feels like a misfire

My 97 5.4 is right at 100,000 miles. There is what feels like a misfire when the engine is around 1300-1400 rpms and in top gear. Say Im on the road going 40-50mph. If I get to an incline there is what feels like a misfire. To me it seems like there is not enough power at that rpm to push the vehicle so the engine is "coughing". I can push down on the gas pedal a little and sometime it will cough more but wont downshift. It takes a lot of pedal press to get the engine to finally kick down into a lower gear. When it does kick down, the rpms really go up to around 3000 to 3500 rpm. To me I should be able to press a little to down kick shift and it should do it smoothly and go up to about 2300-2500 rpm not 3000-3500. What might cause this. Could it be something messed up involving the trans and shifting or might it be the cat that is clogged or similar causing the power to be robbed. Anyone else had this experience or solutions?

Sep 30, 2008 | 12:01 AM

lzrj

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Oh, Im might add it does have the heavier duty tans that used the regular Mercon. I forget which trans number that is.

Sep 30, 2008 | 09:56 AM

whoduhmann

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I just went through a condition identical to what you're going through. Mine was a bad Coil On Plug. If your Check Engine light is on have an Auto Zone or Advance Auto Parts do a diagnostic check for you. They do it for free.

Sep 30, 2008 | 04:06 PM

lzrj

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Ya, I did have two plugs go bad in the past and at first thought that was what was happening again. But it does not act the same as before. The bad plug made it do it a lot worse and more ofter then what this is. I also do not get the engine light. Do you know if it will throw a code without the engine light coming on?

Sep 30, 2008 | 06:11 PM

Ron W.

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From: Stockton Ca.

Your tranny is most likely an E4OD, the white decal on the door will show an "E" for the trans. if I'm correct. As far as your problem goes, do you have or have access to a scan tool that can take a "snapshot" of the PID's when this occurs? If so post them.

Sep 30, 2008 | 10:42 PM

lzrj

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I may see if the Oreillys Auto store close by will let me take their scanner out for a test drive. Not sure what you mean by "snapshot". I dont know if their tool will pick up any readings when it happens if it doesn't cause the engine light to come on.

Yes, the E40D is the transmission. I have never towed with it and all 100,000 miles have been easy. Hope it is either a coil pack or clogged cat over a problem with the trans.

And who put that funny ad in my original post

Oct 1, 2008 | 09:36 AM

Bear River

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A clogged cat would be the result of something else wrong, so your moslty likely culprit is a fouled plug, and bad coil, and bad cam sensor. If the cat is plugged, the most likely causes for that are a bad plug or coil, a bad O2 sensor.

Another possibility is a dirty MAF sensor element. This is especially likely if you have an oil impregnated air filter, such as AmsOil or K&N.