Rpm surge in Overdrive and drive

[lild123]

I have a 93 explorer and have been experiencing an issue in overdrive and drive even, in overdrive I get to 45 mph or so and depending on the load of the engine the rpm will fluctuate up and down, same with drive at a lower speed. I changed the transmission fluid recently and the fluid was fair, I did the pan drop with filter change. I also changed the tps sensor if that’s relevant. Any input is appreciated!

 

[MrQ]

Are you talking about slipping as in you push the go pedal and the RPM's jump with out any acceleration? There is a thread on here about adjusting the bands in the transmission.

Hypothesis: I think sometimes material gets built up between the bands and the drums on high mileage transmissions. When you drain and fill with new ATF the detergents break it up and wash it out (as it's supposed too). This could cause the bands to loosen up when holding the drum allowing it to slip requiring them to be re-adjusted.

 

[lild123]

Are you talking about slipping as in you push the go pedal and the RPM's jump with out any acceleration? There is a thread on here about adjusting the bands in the transmission.

Hypothesis: I think sometimes material gets built up between the bands and the drums on high mileage transmissions. When you drain and fill with new ATF the detergents break it up and wash it out (as it's supposed too). This could cause the bands to loosen up when holding the drum allowing it to slip requiring them to be re-adjusted.

It accelerates but the rpm will raise and lower, someone told me it was almost like a old Chevy tps sensor going bad? It is throttle related. I’m not sure how to describe it but you know how it goes into overdrive and then the rpms drop again like a micro gear engaged? It keeps bouncing between that. I don’t know a thing from atom about transmissions and that’s the best I can describe it lol but it don’t feel like a slip it jerks when it does it sometimes

 

[lild123]

This morning coming up A mildly steep hill I came to a sudden stop
, My RPMs drop kind of bad and the whole front end shook and then the RPMs came back up

 

[lild123]

here’s a video of the rpms

 

[Roadrunner777]

If we took the trans fluid change out of the equation, I'd be thinking this is fuel starvation, particularly when you say it depends on the load on the engine.

 

[MrQ]

Do you feel the engine bogging down?

 

[lild123]

Do you feel the engine bogging down?

Yea

 

[lild123]

If we took the trans fluid change out of the equation, I'd be thinking this is fuel starvation, particularly when you say it depends on the load on the engine.

Yea but only in D and OD ? Could that be possible ? I can always test fuel pressure

 

[MrQ]

Before we attribute it to the transmission and open that can of worms, check the fuel pressure and see if there are any codes.

 

[lild123]

Before we attribute it to the transmission and open that can of worms, check the fuel pressure and see if there are any codes.

I’ve had a code 542 forever but I replaced the relay

 

[Roadrunner777]

If you have the fuel pressure gauge, it's a 5 minute thing, but... in your case I'm more interested in volume, which you can do with the gauge as well... there are videos on line for that. This could just be a clogged fuel filter, if you are feeling lucky!

 

[lild123]

Update boys, my maf wiring was bad. I put a new harness on it a couple months ago and kind of honky tonk rigged it and it came back and bit me on the butt.

 

[Renegade444]

I just bought a lowish mileage 94 explorer and mine seems to do this when going 60+, feels like the torque converter clutch is being activated and deactivated slightly. Is this what you were experiencing?

 

[lild123]

I just bought a lowish mileage 94 explorer and mine seems to do this when going 60+, feels like the torque converter clutch is being activated and deactivated slightly. Is this what you were experiencing?

Yea I initially thought mine was a trans issue, you can watch my video in this thread and observe my rpms when it did it. It would do it constantly

 

[transman304]

Sounds like a TCC problem. Is the RPM fluctuations 200-300?

 

[lild123]

Sounds like a TCC problem. Is the RPM fluctuations 200-300?

You referring to my issue or Renegades?

 

[Renegade444]

Yea I initially thought mine was a trans issue, you can watch my video in this thread and observe my rpms when it did it. It would do it constantly

I will take a video I’m just a second and upload, the truck has been sitting for awhile, it looks very similar but mine is more systematic, about every 10-15 seconds it will fluctuate, does it at lower speed too but less noticeable

 

[dcgerard]

I had a similar problem like in the video, and it turned out I had some bad plug wires. Swapping them out cured my problem. I can see how a MAF sensor can do the same thing with bad wiring, but what the video screams to me is a bad fuel pump too. Glad it was just the MAF though. That's a lot easier to work on.

 

[Renegade444]

Sounds like a TCC problem. Is the RPM fluctuations 200-300?

Yes it’s between 200-300 rpms but only when I’m on the interstate doing 60-70mph I can barely feel it at lower rpms