Help: Very Low Power in Drive but fine in 2nd gear

[ELW2]

I have a 1994 Land Cruiser with 190K miles.

Just today I notice that the vehicle has *very* low power when pulling away from a stop.

If I floor it, it moves forward slowly (and the engine does not rev as high as it would in Neutral.)

However, if I manually shift down into 2nd or Low gear, the vehicle has normal power.

Once the vehicle gets up to speed, say above 30 mph, there are no noticeable problems.

The vehicle burns about 1 quart of oil every 1,500 miles.

I crawled under the rear end and checked the emergency brake, and it appears to be OK.

The check engine light has been on for several weeks -- an O2 sensor problem.

Any ideas for other stuff I should check?

[iaintscared1969]

It sounds like you have a tranny issue. My A440 is doing the same thing on a fresh 5k rebuild from AAMCO. I drop the pan and there was no pre filter and I found small pieces of metal in it. YEAH to me I think it is the overdriv clutch but I am not sure.

[Beowulf]

Check the kick-down cable adjustment.
-B-

[ELW2]

Thanks very much for the input so far.

I just went out and inspected the kick down cable (aka throttle cable). The metal stopper on the cable is about 1mm from the end of the redish cap, as it should be.

As an experiment, I turned off O/D via the button the on the shifter handle. The first time I pulled away from a stop I believe I had more power. However, after I got back from my 2 minute trial run, my "O/D Off" light is flashing, indicating a problem. And now I no longer have extra power pulling away from a stop with O/D Off.

Other ideas on the culprit on things I can try?

[ELW2]

I jumpered TT and E1 in the Diagnostic box. It returned the following codes by flashing the "O/D Off" light:

61 (Defective No. 2 Speed Sensor, severed wire harness or short circuit)

62 (Severed No. 1 solenoid or short circuit)

63 (Severed No. 2 solenoid or short circuit)

64 (Severed Lock-up or short circuit)

65 (I think this is the code for No.4 Solenoid, but not sure)

I doubt all 5 components would have failed at once, so I am looking for a common link.

[ELW2]

I jumpered TE1 and E1, and received the following codes:

28 (No.2 Oxygen Sensor)

71 (EGR valve malfunction)

I don't think these are related to the transmission/low power problem I'm having.

[ELW2]

Well, I slept on it, and I think the most likely cause is either the "No.2 Speed Sensor (in ATM)" or the "No.2 Solenoid" which I think handles the 1st --> 2nd shift.

I think these components are both accessible by dropping the AT Oil plan.

Is it difficult to replace those two components?

Does anyone think something else is worth checking/diagnosing?

[Beowulf]

Cruiserdan replaced both shift solenoids on his a few years ago. He said it was an easy repair and took about 1 hr. Find his post and he describes the symptoms he had. He did not document the repair as I recall.
-B-

[ELW2]

Thanks very much Beowulf. I found the thread you referenced and posted a clarifying question on it.

As an update, I just cleared all the problem codes by disconnecting the negative battery terminal for a couple minutes.

My Check Engine light went away (that was just an O2 sensor anyway).

Now, I just get Transmission codes:

62
63
64
65

Code 61 (No.2 Speed Sensor) is no longer reported as a problem.

[wildsmith]

I would suspect a wiring fault with all those codes coming at once. I'd have a look at the tranny wiring loom connectors in the engine bay just where the loom dissapears down the tunnel. If there's nothing obvious wrong at that connector or along the rest of the wiring you can get at you'll have to drop the oil pan and test the solenoids.

Dropping the pan is easy, a 1/4" drive and a flexible nuckle joint will make getting at some of the bolts at the cross member end a lot easier. It's very messy though, if you can, drain the ATF and leave it dripping for a few hours or you'll be tasting ATF when the pan comes off.

With the pan off, access to the solenoids is very easy. The FSM (see the manuals thread in 24 volt/diesel forum) documents how to test the solenoids quite well so I won't repeat that.

If the solenoids check out then disconnect the tranny ECU and do continuity tests on the solenoid wires from the ECU to the solenoid and from the bulk head connector to the ECU & solenoids to work out which section of loom failed.

Hope this helps, I've had to deal with quite a lot of tranny trouble.

[hj60]

Some 94s have an issue with the pigtail @ the trans. Take a look. I'd bet its showing lots of bare wires and corrosion. If you've caught it in time, you can clean it up and gob it with black silicone and dielectric grease. Otherwise, you'll be after a new pigtail.
I know of at least one case where the pigtail was eliminated and the wires soldered directly into the trans harness connector. I do not recommend this, but it is a possibility.

[landtank]

coming late to the thread but I remember CDan telling a story where a leaky PHH had contaminated and shorted out the connectors for the tranny which are located just under it.

Also, don't discount a problem with the engine harness at the EGR as those signals pass through there as well.

[ELW2]

First of all, a big thank you to everyone who contributed and shared ideas for me to investigate.

Those who suspected a wiring fault were right!

Just above the starter there is a grey plastic 6-wire connector. A damn rodent gnawed the connector completely off!

This explains why the vehicle threw 4 transmission fault codes at once.

I'm not sure if I have enough slack in what's left of the wire to solder them together.

I might need to remove the starter to get better access to the area from below.

Well, the good news is that the problem is identified and now I just need to figure out a good way to fix it.

Thanks!!

[landtank]

Which side of the harness, tranny or ECU?

[wildsmith]

Good to hear you're not looking at a tranny rebuild Comiserations on dealing with that connector, it's a real PITA to work on. I've been able to remove the various clips that hold the loom to the tranny and that provided a lot more slack to work with ...

[ELW2]

Originally Posted by landtank

Which side of the harness, tranny or ECU?

Unfortunately, both sides. My young daughter found the wire connector lying on the ground and asked me if it had anything to do with what I was working on. :-)

[ELW2]

Originally Posted by wildsmith

Good to hear you're not looking at a tranny rebuild Comiserations on dealing with that connector, it's a real PITA to work on. I've been able to remove the various clips that hold the loom to the tranny and that provided a lot more slack to work with ...

Amen brother.

Removing the loom clips to create slack sounds like a good idea. Thanks very much for that.