Stumble on acceleration with WOT

[Sndsational]

I was driving the old Exploder tonight and made a turn then got on the throttle .,..pretty much WIDE OPEN. In doing so, there was a hesitation. almost like there was nothing for power....then it got up to RPM and off I went. any ideas why this occured. Never really noticed it before.

thanks

 

[colintrax]

first is because they just do that.
second, get a cold air intake, got rid of the problem for me.

 

[X6StringerX]

Did it feel like it was missing? When was the last time you filled up with gas? You could possibly have some water in your fuel. Dump a bottle of Heet in your fuel tank. It comes in a yellow or red bottle. The red bottle is iso-Heet and usually costs a few cents more. The last time I checked, it was only about $1.50 per bottle. It seems that I end up using a couple bottles every winter to get rid of water in the fuel system.

 

[2000StreetRod]

fuel filter change?

What engine do you have?

Have you changed your fuel filter in the last 30,000 miles? If not, I suggest that you do and then add fuel injector cleaner to your tank.

At WOT the PCM utilizes a set table for Air/Fuel ratio. You may want to check your throttle position sensor (TPS) to make sure the voltage changes continuously from idle to WOT.

If its been six months since you've cleaned your MAF sensor you might try that.

Are you still running the stock type air filter and enclosure?

 

[Sndsational]

I have the 4.0L with I believe the OHC.

This vehicle is actually a nightmare!! I have done so much and continue to do more, but cannot afford to get out of it right now. In the past year, I have had the following done:

Transmission rebuild
front and rear differential reuilt
Transfer case rebuilt with encoder motor replaced
Cam synchronizer and Cam Position Sensor
Throttle position sensor
MAF
I had replaced the IAC a little over a year ago
intake and valve cover gaskets and new plenum

The stumble on WOT was an isolated incident. I have noticed that I do have a rough idle but it idles at like 800 RPM's in park. I have also done the EGR valve and pressure regulator (i think it is called). When I get on it it goes. Seems to run better in the cold.

My biggest problem right now is that the transmission seems to be "off". My shifts seem to be right there, but it seems that when I want to go, it is always reving out. There does not seem to be any slow progression to highway speed. Also, when I am on the highway at speed, there really is no maintaning....the slightest feather on the pedal and it seems to "kickdown" RPM's go up an then it shifts down....I also noticed that it seemed to run at an RPM, then go up about 200...then drop back down, then up, back down and so on.

I really do not have any idea what is going on, but I want to try and get my truck running the way it has in the pass. No CEL or noted codes...Right now I need HEEEELLLLLLPPPPPP!!!!!

 

[jremington59]

I have the 4.0L with I believe the OHC.

This vehicle is actually a nightmare!! I have done so much and continue to do more, but cannot afford to get out of it right now. In the past year, I have had the following done:

Transmission rebuild
front and rear differential reuilt
Transfer case rebuilt with encoder motor replaced
Cam synchronizer and Cam Position Sensor
Throttle position sensor
MAF
I had replaced the IAC a little over a year ago
intake and valve cover gaskets and new plenum

The stumble on WOT was an isolated incident. I have noticed that I do have a rough idle but it idles at like 800 RPM's in park. I have also done the EGR valve and pressure regulator (i think it is called). When I get on it it goes. Seems to run better in the cold.

My biggest problem right now is that the transmission seems to be "off". My shifts seem to be right there, but it seems that when I want to go, it is always reving out. There does not seem to be any slow progression to highway speed. Also, when I am on the highway at speed, there really is no maintaning....the slightest feather on the pedal and it seems to "kickdown" RPM's go up an then it shifts down....I also noticed that it seemed to run at an RPM, then go up about 200...then drop back down, then up, back down and so on.
I really do not have any idea what is going on, but I want to try and get my truck running the way it has in the pass. No CEL or noted codes...Right now I need HEEEELLLLLLPPPPPP!!!!!

That would be your tranny slipping.

I just took mine off the road and got another because it got so bad I couldn't get it to 60 without a fight. Eventually there was a constant slip in drive.

 

[Sndsational]

I am able to get to speed and the truck will do 80. I also has actually been rebuilt 2 times...once 2 years ago, but I think it was a botched job. Then again about a year ago. Like I said all the shifts seem to be right there. Can any body tell me where the truck should be for RPM's at what speeds?

I have brought it back to the shop several times to be evaluated and they say it seems fine. I think it is something else and not the tranny....I think it is more some thing electronic, but I know really nothing about cars. Any input it good input.

I know at one point I was trying to clean my throttle body and stuff and sprayed cleaner into the TB itself...any chance I fouled up sensors?

 

[2000StreetRod]

Sohc & 5r55e?

It would be helpful if I knew for sure if you have the SOHC or the OHV. You can click on the following link and then scroll down to post # 4 which includes photos of the intake plenum of the SOHC.
SOHC PCV Valve Mod thru 2000

If you have the SOHC then you probably have the 5R55E 5 speed electronic shift transmission. The first thing I would do is check to make sure your transmission fluid is not low. Your transmission torque converter will not lock up unless the PCM is in closed loop. If you're having performance issues then the PCM may be staying in open loop.

 

[Sndsational]

I have the OHV.....X Code in the VIN with the 5R55E Transmission. Nope this helps.

 

[jremington59]

Both my explorers do about 2500 rpm's at 75 mph.

 

[Sndsational]

Well, that is right about where mine is. So my assumption is that it is right.

I really think I have a restriction somewhere and / or a sensor that is not doing its thing.

Can someone read back on the thread and kind of help me through and break this down?

Thank you for the help....so far it has been great!

 

[jremington59]

My area is light on good tranny people but I was told my problem could have been a bad valve body gasket or a bad sensor.

Mine started slipping back and forth a few hundred RPM's and eventually it got to where I had to remove my foot from the throttle and let it "fall" into drive. If I didn't the tranny didn't engage and it was like I was in neutral.

 

[Sndsational]

This is where the questions lies. It never seems to be out of gear. It runs like there is so much sensitivity to the pedal and there is no range...it drops down increasdes RPM's and then shifts. But like I said, i only need to feather the pedal... I mean it is almost like i move a muscle and off it goes.

Any way...any info is good info. Please let me know

Thank you

 

[Sndsational]

Ok, so here is the deal....I am looking for someone that is good with explosives to blow up the Exploder!! Anyone?

Really, I cannot take this thing any more. First off, the tranny is really got me baffled. It has been rebuilt 2 times in as many years...still does not seem right. Seems like it is always shifting. Any chance it is responding to the throttle cable having a lot of play in it?

Next, I just put two brand new whel hub assemblies and the darn thing is still making a wawawawawawawawawa noise when I take my foot of the gas and coast to a stop. Any ideas...new brakes and rotors all around too!

Finally, I noticed that lately the damn thing idles kinda ****ty...but in reading the other posts I noticed there is an issue with the 4.0L and Bosch plugs...so looks like I will be changing those this weekend.

Please, any info is great...I really like the truck, just need to get it back in shape!

Thanks

 

[Sndsational]

can you clarify this

If you have the SOHC then you probably have the 5R55E 5 speed electronic shift transmission. The first thing I would do is check to make sure your transmission fluid is not low. Your transmission torque converter will not lock up unless the PCM is in closed loop. If you're having performance issues then the PCM may be staying in open loop.


Can you explain the open/ closed loop and also how to correct if it is the problem?