First off, this is about my 2003 4.0L 2wd.....

For the longest time, I had a buck/jerk in the truck at cruising speeds, low RPM's on the highway. Only happened in bad weather (weird?).

Then when winter came around, when I would get the truck to normal operating temperature, it would stall when I put the gear selector in "park".

After pulling out my hair for the past year, and catching up on ALL maitenance first (fluids, plugs etc.....) I gave up and went into the dealership.

I had some anxiety about this, not knowing what they would say (or the possibility they would not find anything)....

Long story short, $250 later of all things, my air box lid was not shut 100% completely, there was a small gap where the two halves come together, but not big enought to stick my baby finger in, but a crack none-the-less.

The fix: a plastic zip-tie to shut it completely.

That was the fix! No more buck in bad weather (and I can say for sure since I just drove 3000km in blizzard conditions where it would normally di ti every few minutes). No more stall when I put in park.

All I can say is I am very happy the dealership found the problem. Fixed it, truck runs better than it ever did. Its unfortunate I had to pay to find that amount for that solution, but it was better than throwing IAC's, MAF's, PCV's at it only to not fix the problem.

I leave this in hopes it may help someone experiencing similar problems.

 

I'm not going to say this is not true. They did what they did to fix it.

But I gotta tell ya.. I don't understand why this would matter? Would seem to me that even if the air passing the MAF were turbulent.. it wouldn't stall and such?

Hum... I'd like to know more about why this is?


Rich

 

Weird.

But if it's fixed it's fixed. It's just always nice to have a sure solution to any problem.

 

The tech that worked on my truck explained it to me...

The bucking at highway speeds was the spikes in the pressure readings made by the MAF. If the system was air tight, the filter would equalize the pressure seen by the MAF. The reason I only felt it in bad weather was cause the ambient pressure was alot lower than on a normal day (only happened in very bad weather, like severe storms with high winds) causing the readings to go so out of whack that the MAF was not able to compensate for the distortion.

The stalling when put in park, I cannot explain, but once it started to stall a a month or two ago, it did it everytime, never would it "not stall". And once the zip tie was put on, the RPM's don't even think about dropping. I took the tie off to "test if I was ripped off". First trip to the store, stalled when I parked. Put zip tie back on it stopped.

I can't complain. They did what I paid them to do - I am happy.

Ohh, and of the $250, $150 was just to hook up the truck to their ford-computer, standard procedure when a problem like this is brought it (even though I new it had no codes, they had to do it), and the rest was one hour of labour, and a new air filter.

Can you believe, they threw in the zip-tie and didn't even charge me for it!

 

Those Ford OEM zip-ties cost a fortune too!!!

 

you got ripped on the $150 diag fee, we charge $45 at the dealship i work at

rich, this is a legit problem, particularly seen on fusions and edges

 

Had a similar problem only when it snowed going between 45 and 70. It was the TPS (throttle position sensor). Replaced it and works great, i discovered the answer by accident while doing some cleaning around the throttle body. I took off the TPS and the spring would not return. Easy fix and was about $28.

 

That's interesting I had that problem when the truck was new... I'll keep that in mind.