Vang530

1985 Toyota Pickup Xtra Cab SR5 4x4
22R-E @ 148k miles
A/C, Power steering, etc..
A340F Automatic Transmission (19 bolts)



Just bought last month...So my automatic transmission skips second gear about 80% of the time and goes straight to third gear. It seems to get really bad when taking turns.. shifts into first and then immediately to third gear and really bogs down. It also won't kickdown even when playing with the gas pedal at WOT and pumping it. I have to manually downshift it to 2nd gear when I go up hills or when it bogs down around town. I've read all over the forums and searched all over the place including the AW4 transmission found in Jeeps which are the same.
My searches turned up into it most likely being the solenoids coming stuck so I went ahead and replaced all three of them today. Found no abnormal amount of shavings, filter looked fine, and bright red and smelly as new. After the test drive, it was still bogging down and skipping second or shifting way to early which of course about pissed me off considering the prices of solenoids. I've no clue what it could be now other than TPS or just rebuilding the whole dam tranny.

UPDATE!
Installed new TPS, it shifts awesome and actually downkicks now!!
I found out that the old TPS had a crappy worn out spring even though it tested good, took a long time for it to snap back compared to the new one which was instant. Solved most of my shifting problems...

UPDATE: UPDATE:
Replacing stuff here and there and now it is running extremely nice & clean except for that it stumbles and bogs down around 30-45MPH constantly & only at this speed.
- What happens is it suddenly drops down from say 1.5k-2krpm crusing down to 600rpm and slowly creeps back up... about 60% of the time when this happens the belt will make a quick chirp when it bogs and drops the rpm.
- What also happens during this is if I let go of gas pedal and give it more throttle the rpm comes back to normal again but the belts will slip and chirp about 80% of the time and will keep on doing it until you let go of the throttle once again...even 10x worse going uphill...maybe due to to the abrupt rpm changes so the belt can't catch up? I dunno, but the fan belt does start to look frayed up even though its new. Also when I floor it, it has tons of power and never bogs down~. In Power mode ECT it almost never bogs (atleast not as noticeable), but belts squeak while shifting only.

All New Parts I Replaced on truck so far:
- NGK V-Power Spark Plugs
- Napa Premium Wires, Cap, Rotor
- STP Air Filter
- Wix Fuel Filter
- All New Silicone Vacuum Hoses
- V6 Brake Booster & Master Cylinder
- Numerous bottles of various injector cleaners
- Seafoam
- TPS (solved most of my problems I described earlier) (adjusted 4crawler specs)
- Transmission Solenoids (all 3 of em)
- Transmission Filter
- Cleaned EGR
- Cleaned Throttle Body (Intake Manifold still full of black gunk)
- Hayden Transmission Cooler added
- Denso Starter rebuilt
- Denso Alternator rebuilt
- Idler Pulley
- Valucraft Belts! (Don't ask, my dad got them for me lol)
- Denso O2 Sensor
- ECT sensor + thermostat switch
- Hayden Fan Clutch
- Dorman Exhaust Manifold & Gaskets
- Other stuff I can't remember....

All these items but still this one minor problem is making me crazy...
Only things that I can list that might be causing my problem would be injectors ... btw no engine codes at all...
Sorry for the long write up and thanks to anyone who can help.

Zpd426

check out post #11

http://www.toyotanation.com/forum/81...lfunction.html

Vang530

Thanks for the link. His was very similar to mine except it was 3rd gear skipping and not 2nd gear. If it does turns out to be a valve body problem (I hope not), I'm not mechanically inclined enough and will most likely have to take it to a shop for which I have no money for.

Utah4Runner86

iTrader: (1)

Did you test the TPS signals at the ECU? If the TPS is solid, it could be the connector or wires. I ask because I had a cracked TPS connector that would work itself loose, and when it was loose my truck behaved very similiar to what you're describing.

Vang530

I have not checked out the TPS signals at the ECU yet. I'm assuming it is also in the 4crawler guide? I'll go to sleep and update you guys about this then after I test it later. Thanks.

Vang530

Sooo I checked out my truck again today. TPS is fine and all within spec. No dead spots going from idle to WOT from the TPS itself and also the ECU signals. I even got a new ECU to test out and it made no difference. Still skips 2nd gear and bogs down bad even at WOT.
I am suspecting it is the TCU or whatever since it shifts fine manually with it disconnected... no slippage, no grinding, no hesitation, no bogging, etc. and yes 2nd gear works if shifted manually no problem, which most likely rules out a mechanical problem.
Is there any place I can get a TCU at and what ones are compatible with my truck? Finding an '85 4x4 automatic TCU is gonna be hard in any junkyard. I cannot even find its listing on autozone...

Thanks guys.

Vang530

Does anyone know if there is a testing procedure for the TCU like the TPS to check if its OK or not?

SR25JD

had one that did the same ......have you checked the torque converter ?I replaced mine and it ran fine....later sold it...i wish i would have keep it....

SR25JD

i will buy it........

Vang530

I have not thought about the torque converter being the problem, but I do not think (or hope) it is the culprit in my case. O/D is also working fine with no codes to be shown that I know of.

How can I check the torque converter?.. Thank you.

Vang530

If it ends up needing a full tranny rebuild I will most likely lol..

or just end up letting it sit for a couple months until I get the funds

westjohns yota

dont rebuild the auto tranny, ud better off 5 spd swapping it, theres a weird thing about this, my dads dodge had a similar problem, the wiring harness could have a short somewere , pull some of the wireing harness apart and check for frayed or loose wires, all in the engine bay and under the dash, my dad ended up fixing a few frys under his hood and its totally fixed his problem, just an idea

Vang530

When I unplugged the TCU, I did notice a small blue streak where one of the pins and the connecter meets at... would this be some type of corrosion or something? It is a really small blue streak about half the size of my pinky fingernail...
Of course after I was done testing I put some dielectric grease on the thing.

Sadly I need to keep it as an automatic. My handicapped father will drive it from time to time when I'm not using it, so no 5 speed swap in the future. As of now I will check all the wires and save up for some shop time... I'll report back what I find in the rat's nest of wiring. Thank you.

Vang530

I checked most of the wiring today and everything looked fine.. no real corrosion or frayed wires to be seen. For some reason though I took it for a test drive and I actually have 2nd gear now and it even down shifts when going up hills OMG! Hopefully it won't go back to going through 2nd gear in 10 seconds and bogging down in 3rd again.

Now a new problem after it was working on my test drive...when it down shifts or accelerates under load I hear a loud ass squeal (really bad going up hills). Not a peep in idle, only under heavy load and shifting so it's kinda hard to hear where its coming from. Sound gets louder as I go on the gas and I have to step off the gas to make it stop squealing, sometimes doing this two or three times to stop the noise (only under load or when the tranny shifts). I replaced all three belts when I first bought it a month ago, so that rules out the belts I guess.. but if a tension idler bearing is bad won't it make the squeal in idle as well, and not only under load or when the tranny shifts? The belt squeal doesn't happen as much in power mode if that matters.

I still have a code 7 so I will go ahead and replace the TPS anyways when I get the money even though it checks out good even at the ECU.

Thanks for the help guys.

SR25JD

I still feel that the problem is the torque convertor..a good mech.in your area can check it out for you mmine was throwing the same codes......food for thought....

Vang530

Mind telling me how much it cost you so I can start saving up?

calvinh

I have a 89 4Runner with a 3.0/auto that has the same issue. If I'm not manually shifting it I hit overdrive by 30 mph. I've taken it to 4 different tranny shops and got 4 different answers from solenoids to converter to valve body to needing a complete rebuild. None of which have been a cheap estimate. I agree with the comment earlier about swapping in a 5 speed. If you source your parts right this can be done for around $600 doing the work yourself. I'm going to be in to mine for around $300 only because I already have most of the parts. And there is a ton of very detailed write-ups on the swap here and on some of the other sites.

justin_4runner

it could still be a belt for the alt or something squealing, i would check it and make sure there all good, sometimes they will stretch out a little after being on for a little time.

Vang530

Update!
Installed new TPS, it shifts awesome and actually downkicks now OMG!!
I found out that the old TPS had a crappy spring, took a long time for it to snap back compared to the new one which was instant. Solved most of my shifting problems...

Still some bad news though.. still bogs down around 30-40MPH, never any other speed and squeaks and chirps BAD around the same MPH when it bogs down. New belts, new alternator, bearings looked OK to me, belts aren't loose...

Also belts or something chirps once in awhile when it shifting, however the shifting isn't hard and is very smooth??

Could it be a fan clutch that is making the horrible sound?
Also could the bogging down around 30-40MPH be injectors? I put new NGK plugs & wires & air/fuel filter about 500 miles ago and still does it. The intake plenum however is CAKED with slimy black oily sludge, so maybe the injectors are going as well which causes the bogging down? I dunno... or it could just be my cracked exhaust manifold

Vang530

Update:
Put in new idler pulley, wow did it make my engine seem alot quieter. My old one was all gravel noisy.
Also put in a new fan clutch.... still squeals every time the transmission shifts like a belt is loose. and yes I did tighten them and new belts. don't suspect the alternator since its a new denso reman one.... what next?