More issues with throttle response....

[markedman450]

So like previous posts...i have an issue with my 01 explorer. Seems like lack of power, and while im driving the car seems to drop to 2k rpms and get stuck there, u have to floor it or let off the gas and press it again to get it to climb. I also get an issue where if im accelerating hard, it hits 3.5k rpms, starts to drop a little then it picks back up, mean while my foot is flooring the gas pedal. Ive replaced wires, plugs, coil pack, TPS, intake, etc...cleaned the idle sensor and MAF.. I unplugged my MAF, car doesnt like running without it plugged in but it eventually smooths out after bouncing up and down, ran it without being plugged in, seems to run exactly the same except when it shifs it seems to kick a little bit more. Could the MAF just be going bad...what else could it be??

 

[manaen]

Have you checked your fuel pressure? sounds like it could be a fuel delivery problem.

Are you getting any codes at all? seems like a pretty serious problem to not have any codes.

 

[markedman450]

Just replaced the fuel pump and regulator a few weeks ago and still same problem, had a garage check pressure too. No codes at all. Just feels off, like driving steady down the road, you will feel the car drop in rpms and just hang there...almost like its dropping to high gear and getting stuck...and pulling the MAF harness off didnt seem to effect it much except for a more jerky shift through gears...not sure if that helps.

 

[ThePhoenix]

what about the fuel filter?

 

[manaen]

Yeah what he said ^^^^

 

[ZBlackBeast]

What about the injectors? HA. wow, i cant really think of anything. How is the power going to the coil packs?

 

[markedman450]

Fuel Filter is new, power to coil pack is good, just had injectors cleaned and checked. Anyone know if these MAF issues could be a sign

 

[manaen]

Try turning off your overdrive, I just re-read your post and realized that could just be your converter locking into overdrive. (which is normal)

Also try lifting your foot and getting back on the gas, the tranny will downshift out of overdrive

 

[winsorcoke]

I could be mistaken, but I think if you unplug the maf sensor the computer goes into a default program with default sensor values. That would explain why it started bouncing and then smoothed out when unplugged.

 

[markedman450]

when i take it out of overdrive it doesnt do it as bad but still does it...i dont want it to do it anymore or have to bounce the gas pedal...since it never did it before, could it be a transmission sensor??

 

[manaen]

does your tranny seem to shift harsher than before? does your OD light blink at all?

 

[markedman450]

No blinking lights at all, no codes, nothing. Only time it shifted harder was when i tried driving it with the MAF unplugged. It seems to shift wierd sometimes, especially when i gun it, sometimes it doesnt shift quick enough like its hanging...or it doesnt shift until i put it to the floor then it jumps into one gear just to go into another gear right away...Im wondering if it could be some tranny sensor that tells the vehicle when to shift, maybe its going bad and trying to keep the car in overdrive, that would explain why it keeps bogging down to 2k rpms and i have to either punch the gas or let off the gas and hit it again to get some rpms.

 

[ThePhoenix]

if I remember from my friends mustang, isnt there a throttle kickdown? OR, like on my wife's jetta, there is a screen in the tranny that detects fluid pressure. If that is clogged, no shifty

either that or a vacuum....

 

[markedman450]

I just had the tranny filter replaced less then a yr ago. And if theres a vacuum leak i cant find it.

 

[manaen]

I believe the 01 sport should have the 5r55e, that tranny is completely shifted by the computer. The stock shift setup is purely for gas mileage and that soft plush feel. That means the tranny will try to always keep the engine rpm's as low as possible to conserve gas and the shift silky smooth (not great for tranny life). What your describing is pretty typical of a stock tranmission. It will hold overdrive as long as it can, and only kick down if you floor it, or lift your foot and get back on the gas which is the computers only redeeming feature in stock form. The shifts can be reprogrammed but you would need to either bribe a ford mechanic, or get a tuner chip like one of the options from www.hensonperformance.com.

If you notice a change in the shifting, it could be that the EPC (electronic pressure control) valve is starting to go bad, they are a known weakness of the 5r55e transmission, they basically loose their ability to hold the proper shifting pressures. There are also othe things that can cause problems like fluid level, or old fluid which can loose it's hydraulic properties when it gets old and burnt. Sounds like if you just had your filter changed you probably also had a fluid flush which eliminates those issues, assuming they used the proper fluid, I always recommend mercon V full synthetic, like mobil 1 or one of the many other options that are full synthetic, not a synthetic blend

You should also adjust your bands to make sure they are properly adjusted, the 5r55e uses them more than previous trannies and therefore they tend to need more adjustment. In the 5r they are not only used for overdrive(5th) but also for 2nd, 3rd and manual 1st.

 

[ThePhoenix]

is the electronic pressure control something you access by dropping the tranny? where is that located? I am just curious

 

[manaen]

The EPC is a small solenoid located on the side of the valve body (inside the transmission pan) I would recommend reading these threads on the 5r55e

http://www.explorerforum.com/forums/showthread.php?t=140987

http://www.explorerforum.com/forums/showthread.php?t=154655

You don't need to drop the tranny, just the pan to access the EPC

 

[markedman450]

Thanks Manaen, im gonna check out about that valve. Yea i def. have noticed a big difference in the way its shifting, is it an expensive fix? Yeah fluids were changed too so ive been checking the levels, all good so far.

 

[manaen]

well from ford I believe it runs about $180, but you can get it cheaper online on the ford parts network, or I guess they changed thier name to the fast parts network.... just see the links sections its in there