Idle surge/lurch forward when stopped and brake on

[Jester1994]

Hey guys, I have noticed about 4-5 times in the last few weeks that my Explorer has lurched forward a few inches when I am stopped in traffic or at a stop sign in the middle of driving a few miles around town or so. It seems that all of a sudden the engine idle jumps a few hundred RPMs (or more) and even when my foot is on the brake, the truck lurches forward a bit. If I didn't have my foot on the brake, I am sure the power produced by the second long surge would push me a few feet on level ground. It's basically as if I kept me left foot on teh brake the tapped the gas for a second to jump the truck a bit.

Any ideas? Could it be a computer issue? I do have an apten chip and have always noticed a few quirks in the warm weather last summer on my drive home from Idaho, such as the Explorer would jump out of gear and sometimes shut off while driving on the high way, not good and I guess that's not just a little quirk! No CEL was ever on, the Explorer would just shut off, I would have to stop and turn the key off and then back on to start it.

 

[97ebEXPLORER]

Did you by any chance have the A/C on when this was happening? Because my ex sometimes likes to jump a little bit when stopped with my A/C on

 

[Jester1994]

I am not sure, I might have had it on, but this is no lurch because of A/C, it has not happened anytime before. It's actually not safe what happaned.

 

[Jester1994]

bump. Any ideas? It lurched forward 2 days ago. Not so good in the city close to cars!

 

[Jester1994]

Any ideas? It lurched forward 2 days ago. Not so good in the city close to cars!

 

[section525]

Mine does that same thing. I don't know what it is. I always thought it was my cam. I was thinking it's an IAC deal. Like your V8 is taking a deep breath right then. I've never came close to hitting anyone though.

 

[Jester1994]

Yeah, it's some kind of "interesting" hiccup. It did it to me for the first time over the 4th of July, so I was a little surprised at a stop sign, ha. Oh well.

I've had it stall a few times (once a month), but it only does all of this stuff in warm weather , summertime.

 

[mynameisaric]

i'm about 14 days late on this one, but my 4.0 did the same thing(alot more with the a/c on) i just got used to it. but i recently chopped the exhaust after the muffle and put a turn down on. killed a little back pressure. not sure how much it hurt horsepower or torque, but its not bad. but the idling smoothed out ALOT! it was the first thing i noticed when i started it up. its not too much louder either. its kind of a drastic ireversible measure to try and smoothe an idle out tho. if you werent planning on doing sumthing like that, then i wouldnt do it. just thought i'd let you know how it stopped happening on my car.

 

[Jester1994]

I know for a fact this is not a A/C related throttle surge. This is a legitimate jump as if I stomped on the gas for a fraction of a second with my foot on teh brake still. I have notice little quirks with the idle recently besides the lurching, which has only happened a few times in the past 2 months. I'll probably run seafoam through when I get a chance.

 

[Scoota]

I am having the same issue... I had the problem several months ago and took it into the shop...they couldn't find the problem. In the last week it has started again pretty bad. It is definitely a safety issue. The car lurches (actually "bucks") forward enough that you could definitely hit someone. At the same time the RPM's surge ridiculously, it get so loud that it sounds like the engine is going to give. In the past I was able to hit the gas and lower the RPM's...however recently I have had to throw the truck in park and turn it off. Twice it turned back on with the accelerating RPM issue still happening.
Anyone?

 

[Jester1994]

Hey Scoota, I pretty much narrowed my issue down to the performance chip I had in the truck. I have since disconnected it and have had no other issues. It would create the same issues you described and also sometimes would inhibit performance on the highway at wide open throttle (seemed like it would flood or the airflow would get choked). So all in all, the chip wasn;t reliable for me.

 

[alcus]

2007 Explorer Lurches When Coming to a Stop

It is like driving a stick and letting off the clutch too fast. It was getting a little scary at stop signs and red lights because if you stopped too close to the car in front of you, there's a good chance that you'd tap it.
Anyway, took it to Ford Dealer and showed them Technical Service Bulletin (TSB) 8-24-4.
This TSB did the following:
Reflash PCM/TCM and perform relearn of adaptive tables to reduce driveline dump while braking.
Cost was $162.70 and it seems to have corrected the problem for now.
Cost breakdown:
Supplies: 14.70
Labor 147.00
You definitely have to leave your car for at least 4-6 hours to complete the procedure.