Delay on Acceleration with A/T

[BrandonVA]

I have an 02 escape with 148000 miles with fresh transmission fluid and i'm having a strange issue. Sometimes from taking off from a dead stop or accelerating after releasing the gas pedal there will be a slight delay before the transmission engages. What causes this? The shifts feel pretty firm but sometimes there is a delay or slight tug (after the delay) when the wheels finally do start spinning (after putting foot on gas). It has a cd4e transmission.


anyone know what's going on here?

 

[BrandonVA]

could it be an old throttle position sensor?

 

[GSCJR]

Low ATF level?

 

[asiancivicmaniac]

Dirty throttle body?

 

[Brybo86]

the rpms increase significantly before the car starts to move? Or the rpms don't Increase like a stuck throttle body?

 

[Warstud]

Did you have this problem before the ATF change?

 

[asiancivicmaniac]

My guess:

 

[friendly_jacek]

I had than when ATF overheated. Long story.

 

[Rand]

probably transmission on its way out. I know 4 people that had those and needed a transmission <100000miles

 

[BrandonVA]

the rpms increase a little bit but not a ton. maybe 500 rpm or so before engaging

 

[BrandonVA]

atf is new and at perfect level. Mercon. It was shifting a little lazy before atf change but didn't do anything like this.

i think what is happening is that the torque converter unlocks when I put my foot on the brake pedal and then reengages when I put my foot on the gas. Problem is there is sometimes a very small delay (fraction of second) before engaging sometimes upon acceleration. This happens maybe 1 out of 10 times. I am thinking it is probably a lazy sensor somewhere but I have already dropped way too much money on this car so I don't want to go about replacing the wrong stuff.

 

[CharBaby]

Originally Posted By: BrandonVA
atf is new and at perfect level. Mercon. It was shifting a little lazy before atf change but didn't do anything like this.

i think what is happening is that the torque converter unlocks when I put my foot on the brake pedal and then reengages when I put my foot on the gas. Problem is there is sometimes a very small delay (fraction of second) before engaging sometimes upon acceleration. This happens maybe 1 out of 10 times. I am thinking it is probably a lazy sensor somewhere but I have already dropped way too much money on this car so I don't want to go about replacing the wrong stuff.


Well, I think it has something to do with the Torque Converter! I have has similar issues in the past with auto transmissions but, only when the drivetrain was cold.

When you replaced the ATF, did you do a pan drop and change the screen/filter? If not, maybe this is the way to go 1st!

 

[TFB1]

AFAIK torque converters do not lock at lower speeds, the fluid coupled turbine transfers power... If it locked before the vehicle is rolling you'd get a severe lurch and maybe stall the engine...

Sounds like it has a internal leak in the hydraulic system or pump could be weak so isn't supplying enough fluid pressure till revs come up a bit... Of course all the newer trans are controlled by the PCM so anything is possible, you should take it to someone trustworthy for diagnosis...

 

[rshaw125]

I am not familiar with this particular transmission. But I do know the GM 4T65E trans can have a delayed engagement issue.
It usually requires a new pressure control solenoid.

My point being if you keep digging you may well find what component fails in your case.

 

[OVERKILL]

Originally Posted By: BrandonVA
the rpms increase a little bit but not a ton. maybe 500 rpm or so before engaging


That's normal. The delay however is not. Probably flat spot on the TPS.

 

[BrandonVA]

ordered a new tps sensor for $15 on ebay last night. i'll update when i get it installed

 

[zzyzzx]

Did you test the old TPS first?