RPM Drop / Transmission question... (1 Viewer)

[Skillet]

When I am driving along, usually at freeway speeds of 50 or more, then I let off the gas, the engine RPM's stay where they are for a few second then drop suddenly instead of just decreasing slowly.
Transmission is not necessarily downshifting but an actual drop in RPM's.

Is this normal for these transmissions? I just lubed all of the cables and they seemed very free so any ideas on this?

 

[Skillet]

Testing and timing it this morning...

Going along at 2200 RPM then take my foot off of the gas completely,
the RPMs stay at 2200 for about 1.5 seconds then drop to 1900 - 2000 RPM.

As I said before, not a smooth drop just a sudden one.

More irritating than anything else. Perhaps the cables are not adjusted correctly.

Hmmmm?

Anyone? Anyone?

 

[firetruck41]

Torque convertor unlocking while coasting maybe? I would think this is normal on any automatic, but I'll have to check next time I drive...

 

[powderpig]

Pretty normal for both 80 series tranny. The TC unlocks for coasting not under a load. robbie

 

[heckler]

I am having the same problem, that is why I am reserecting this thread. Should I be concerned? Is there anything I can do or should do?

Mark

 

[CJF]

I am having the same problem, that is why I am reserecting this thread. Should I be concerned? Is there anything I can do or should do?

Mark

The post above yours seemed like a pretty definitive answer to me...

 

[corsair23]

Robbie (powderpig) says it is normal (post #4) and that is good enough for me

Is the Cruiser "new" to you or are you experiencing something that you haven't noticed before? If so, I'd suggest starting a new thread with the old "I've searched but still have a question" statement.

 

[heckler]

I have had the landcruiser for about two years now and this is the only time this has happened. So, when will it go back to normal, is there anything I can do for this?

 

[corsair23]

I have had the landcruiser for about two years now and this is the only time this has happened. So, when will it go back to normal, is there anything I can do for this?

As stated, I'd start a new thread. Reference this thread and others you've found and go from there seeking help. I assume you've done the routine checks on the fluid level and condition. Maybe try to find another Cruiserhead in your area with an 80 and compare.

 

[corsair23]

Just as a follow up if anyone down the road comes across this thread, yesterday I tested what my '97 LX450 does.

Driving along at 65-70 @ 2100-2200 RPMs, if I let off the gas the RPMs stay at what they were for about a second and then drop down about 100-200. Tried it about 6 times and each time the LX performed in the same manner. This was on fairly level to slight down hill grades.

Not sure this is worth anything but figured since I tested it I would post it up.

 

[jcj_78FJ40]

This is from a 91 Manual.

My 78 fj40 does the same thing.

The Dash Pot reduces Hydrocarbons (HC) and Carbon Monoxide emissions by returning the throttle plate slowly to the idle position during deceleration. This allows the air fuel mixture to burn more completely than if the throttle were closed abruptly. The Dash Pot consists of a spring loaded diaphragm that extends when the throttle is opened, thus drawing in air through suction. The air becomes trapped by the vacuum transmitting valve (VTV) and becomes a buffer on the diaphragm. When the throttle valve is released and comes in contact with the DP actuator pin, the air is forced back out of the DP filter slowly, returning the throttle valve slowly to its idle position.