Jumping and lurching during acceleration.

[rwz23]

I have a 1999 eddie bauer v8. It accelerates fine through all gears but when its in the last two gears it kind of hesitates and lurches and accelerates unevenly. I replaced the DPFE sensor and that didnt seem to fix it so im wondering where to go next. Thanks.

 

[Diff Whack Daddy]

When was the last time you had a tune up? You may not be feeling it in the lower gears as the torque converter has not locked up yet. Once the torque converter locks and provides a direct connection between the engine and tranny(no slip) you will then be able to feel the uneven outcomes of a cylinder missing. This could be caused by several things, but usually it's just simple maintenance of new spark plugs and/or wires. Other things that cause cylinders to miss is bad or clogged fuel injectors.

 

[BrooklynBay]

Welcome to this forum! I've moved your thread to the stock 95-01 section.

 

[rwz23]

I just did plugs and changed all fluids 50 miles ago so they are brand new. I was going to change the wires as well but the factory wires were $106 at auto zone so i skipped on those. it was throwing the egr code p0401 when i did the tune up 50 miles ago but it hasnt come back on. Thats why I initially suspected the DPFE sensor. I know there is a short delay period before the SES light comes back on but I am anticipating the same code.

 

[Diff Whack Daddy]

Is that the EGR insufficient flow code? If so, stop replacing sensors. I had the same issue on my wifes Expedition, changed the entire EGR system out and it ended up being that the orifice tube in the intake manifold was completely clogged up with carbon/dirt build up.

 

[Tbars4]

...This thread may be of some help then..
http://www.explorerforum.com/forums/showthread.php?t=92263&highlight=p0401

 

[rwz23]

does the orifice tube your talking about go from the EGR to the intake manifold. I took a quick look at it again today before I went to work and i saw the thick tube that goes from the exhaust manifold into the bottom of the EGR.... Is that the tube that gets clogged up/is that the one you were talking about? Thanks for the help

 

[Diff Whack Daddy]

No, the one that got gunked up on me was after the EGR valve. I actualy took part of the intake manifold apart to clean it out. On the Expedidtion, the EGR Valve was connected just behind the throttle body and I was able to pull the upper intake and clean out the gunk.

 

[rwz23]

Just another thought... do you think it could be a bad cat converter? like i said i did the full tune up but when I start it, it turns over for a while then when it does start, it doesnt jump right up to idling rpm like my 2000 sport. It starts up relatively slowly and then gets up to idling rpm. My dad took it for a ride the other day and i followed him and it did smell weird when he punched it and he said it didnt have as much power as he expected from the v8... at this point im considering bringing it to my mechanic since he is obviously better at trouble shooting this issue then i am... would a bad cat explain the lurching when I try to accelerate in the last two gears though? Thanks for the responses

 

[rwz23]

oh and it does sound like it has a small exhaust leak somewhere. I havent have time to check into it to find out where but just listening to it sounds like there is one somewhere

 

[jlsparky7]

Run some seafoam to check for an exhaust leak. You can see it from 10 feet away.

I think you might be on to something with the EGR