93 TLeg AT - 4th gear problem

[macipusy]

Seems like the 4th gear on the 93 TLeg 4EAT is not working properly. When cruising on the highway at 75, the RPM's are at 4250. When I let off, they drop to 1200. When I give it a little bit of gas at theat point , it seems to just freewheel until the RPM's climb back to 4250 before the car moves again.

I can sit there all day and rev at 2K driving 70 and the car will coast down until 2K will actually do something in 3rd gear.
Anybody ever have this problem with a AT...it's my brothers car and I never owned an AT car before.

[ericem]

Bad TPS sensor maybe? Sounds like the torque converter isn't locking up in 4th which it should.

Most popular suggestion is do a tranny fluid change takes 4L. Also looking for a tranny oil filter on the cooling lines is a good idea could be clogged.

[macipusy]

I will flush the tranny tomorrow and check the filter....I will check for any changes in the symptoms and report back.

[ericem]

Be good if you had a scan tool you could check out the TPS and make sure it is working properly.

[macipusy]

I actually did tests on the TPS when my brother first bought the car. It was bogging and no power, but turned out to be the MAF.

I did the volt meter tests ant fully closed and open, as well as incremental opening of the throttle plate....all the readings were within Ohm range provided in the FSM.

[wtdash]

Flashing POWER light @ start-up? If so, pull the TCU codes HERE.

Also, do a TC Stall test- DO NOT DO FOR MORE THAN 5 SECONDS!!:

TORQUE CONVERTER STALL TEST

A "stall test" can be used on many transmissions to check its ability to hold torque and the operation of the converter one-way clutch. Some manufacturers don't recommend using a stall test because it stresses the transmission, so if you use this procedure, do not do it for more than five seconds at a time.

Before conducting a stall test, check the fluid level and condition. Chock the wheels and set the parking brake. Start the engine and place the transmission in drive while holding the brake pedal under firm pressure so the vehicle doesn't move. Then push the accelerator to the floor while holding the brakes on. Note the maximum rpm that the engine reaches. This is the stall speed. If it is lower than specifications, the torque converter one-way clutch is slipping. If the stall speed is higher than specifications, the transmission is slipping. Possible causes include a low fluid level, restricted fluid filter, a sticking pressure regulator valve, slipping clutches, bands, shaft splines or one-way clutch.

And

Stall Test Results

Higher than normal RPM indicates one or more of the following:
• Slippage of the forward clutch
• O.W.C. not holding
• Low/Reverse brake slipping
• Overall low line pressure
Lower than normal RPM indicates one or more of the following:
• Incorrect throttle adjustment
• Poor engine operation

• Torque converter stator slippage

The stall test 'normal' values for the Phase 1 4EAT are:
Non-turbo: 2550-2950 RPM
Turbo: 2850-3250 RPM

(Thanks to Legacy777 for this INFO - open this FILE: 4EAT_performance_test.zip.)

For reference I found the WRX 4eat Phase II is 3200 RPM

[macipusy]

Thanks for that info....I will test this tomorrow