crasster

Main Trouble Symptoms:
A) Feels very weak at higher speeds. Have to floor it to go up hills.

B) Sometimes if I floor it, the tranny doesn't seem to down kick.

C) Sometimes when I floor it the tranny does down kick, but its weak.

D) Sometimes when I floor it the tranny does downkick, but it's weak, then I let up on the pedal and floor it again. It down kicks, but sounds weaker than before. Each time I let it up it kind of sounds even weaker.

E) At low speeds it most often seems to do okay, but often won't down kick at lower speeds and feels weak as well.

F) No bump shifts

G) When I first start driving, all the gears seem to shift very smooth and right

H) Nothing in tranny fluid seems to indicate a problem. Pink and smells good.


What I have done that I think could be relevant to fix this problem:
New Fuel Pump
New Fuel Filter
New PVC
New Catalytic Converter
Valve adjustment
New Spark plugs
New Coil
New Rotor
New Cap
New Spark plug wires
New Oil
New Oil Filter

I've also took off the TPS (throttle position sensor) and applied a tat of WD-40 to it because it was barely seeming hesitant. Now it's "snapping" back into place when I manipulate it.

Other things I've done:
Starter
New Battery


Things I'm wondering if could be the problem:
Air Flow Meter (AFM) - Could this cause my symptoms? I'd rather not mess with it if it couldn't because they are $$.

Bad injectors - How could I test and could this cause my problem?

Bad transmission - Since they are complicated. Fluid smells & looks good. Smooth shifting when shifts.


Open to all / any suggestions. I'm getting to my wits end with it. LOL. Once when I was going up a hill the Check Engine light came on but then went off when I went down the hill. Will it record what happened?

Thanks a lot!

MudHippy

Yes, it will likely have a code stored in the ECM if the engine light has come on at all. My guess is it will be a transmission code, possibly not. Regardless, the first troubleshooting procedure for any electronically-controlled transmission/engine is to check for DTCs(Diagnostic Trouble Codes). Here's the link to the 93 FSM A340H Diagnosis System section showing how to do that http://personal.utulsa.edu/~nathan-b...31diagnosi.pdf

EDIT: The 87 A340H is different in the way you check for codes. See page AT-111 in the 88 FSM.

If there are none there still may be a problem with the electronic control system, or with the components it controls. The general troubleshooting section states under "No O/D–3, 3–2 or 2–1 kick–down" the possible causes being "Solenoid valve faulty, Electronic control faulty, Valve body faulty". The next step would then be to inspect the electronic control system. After which the solenoid valve and valve body. You'll need to download the 88 FSM to get the details on how to inspect those, it's not in the online manuals. Here's that(it's kinda big so it may take a couple minutes to download) http://www.ncttora.com/fsm/87-4Runne...4runner_88.pdf You want pages AT-130 and AT-226 for those(solenoid valve & valve body) and AT-120 for the electronic control system.

If any engine codes pop up here they are:

PismoJoe

It sounds to me like a transmission related issue, but keep in mind that this is OBDI. Meaning, if the problem is not "current", you will NOT get a check engine light.

Yes we would all like to think that codes are stored as "pending" or "history", but the fact is that OBDI is primitive, and does NOT store codes that aren't being detected as "current."

I have faced this issue many times in diagnosing issues on OBDI systems, and the only way to truly pull this "intermittent" Check Engine Light is to actually run 2 jumper wires into the cab from connections TE1 and E1, so that when the Check Engine Light comes on while driving, you jump the connections and pull the code right then and there.

Now, keep in mind that you will be driving when this is occurring (off of idle, which is the normal condition in which codes are generally pulled for OBD1) Thus, you will get the TPS code 7, since the ECM is not sensing idle from the TPS when you jump connections TE1 and E1.

Hopefully getting the code pulled will point you in the right direction

MudHippy

From the 88FSM.

PismoJoe

Mudhippy, there are two aspect to mechanics: The real life, and the by the book approach.

Knowing the book side is good to give you some background on general theories and approaches to issues. Arguably more important, is the real life aspect of mechanics. The book is wrong in so many ways I cannot begin to describe, but real life knowledge is in its own sense even more valuable that what an FSM can tell you because it must be acquired from real life situations, day in and day out of receiving problems that must be resolved quickly and efficiently.

OBD1 does NOT store codes, or at least not all the time, and while were on the subject, very rarely do they store codes. It is naive to assume that this is incorrect, and rely strictly on the book the give you the knowledge to solve this issue, because I can tell you from real life experience that there are plenty of OBD1 cars that I have seen that will not store codes. Yes, besides 11 and 13.

Look at crasster's issue from a real life sense. He states that he has an intermittent check engine light. 50-50 the code will not come up. Say it doesn't. So what do you do? From the sounds of it, you will pull out your FSM, read it entirely too in depth, and attempt to plot out viable causes of the issue.

Nothing wrong with this approach, except that it is inefficient and time consuming. My point is that you can't take the FSM as gospel, and especially on the topic of OBD1, you can't rely on the system to function as described.

Therefore, I chimed in and gave some advice on what to do if the likely (real life) event of no codes being stored occurs to quickly help him discover the "current" CEL that is intermittent.

MudHippy

We fundamentally disagree. And that's o.k.! You state your side, I'll state mine.

My philosophy is that Toyota has been manufacturing automobiles since 1937, or roughly 74 years in total. Because of this I firmly believe that they've known what they're doing, or rather building, for most of that time surely. I also believe that there is no higher authority when it comes to servicing a vehicle than the Factory Service Manual. It was built at the factory, they made it work, they know how to make it work again. You can argue that with me 'til you're blue in the face. It changes nothing. Me and the rest of the "professional mechanics" know what's really going on. Toyota took the "guess-work" out of the equation for us, it's called the FSM, PERIOD.

The MAN

ok, arguments aside, I haven't seen the following suggestions:
-compression check... how is the compression with the motor?
-kick down cable adjustment... is the kick down cable adjusted properly? there IS a spec to this, and to find it you'll need to RTFM I readjusted mine last week and it kicks down immediately every time I floor it now unlike before.... what's interesting is, it has always been this way, so that means the monkeys at the factory didn't set it up right!
-TPS adjustment.... it's been taken off and put back on, has it been readjusted to the correct position? There is an adjustment tolerance spec for the IDL and E2 pins on the TPS.... bad TPS or out of adjustment TPS will cause the engine/trans to behave funny

MudHippy

This particular transmission doesn't have one. Kick-down is electronic-controlled via solenoid valves.

ChefYota4x4

iTrader: (5)

The Man, ...... My buddy has an Auto 86 22re, ..... had a Coolant Temp Sensor issue(from what I remember 4Crawler stating, ...."Auto Transmissions are DIRECTLY dependent in some forms on the CTSensor... if the CT Sensor is bad, it can cause the, can't remember, .... 'solenoids'? to have issues)" Sorry to Roger in advance, ..... if I blundered that one, lol. But, it can be found on his site, I'm sure, and definitely on here in the 'search' tab.

Hope you can get a good P.O.E. through the book and some Extra Added Guru Findings, like I have, to find out what's up widat ting! lol. Best wishes.

Edit, ... just now saw MH's above post.... I'll bud out now, hahaha.

MudHippy

From what I've read the transmission can be electronically "locked-out" of O/D if the ECT° reaches a certain threshold, until it falls below it again. Doing this will...blah..blah..blah...

EDIT: Not quite right. So let me have you read it for yourself and see.


BTW, what I think he was refering to is the TPS, not the ECTS.

The MAN

that's nice, I don't have an A340H nor is this really my problem, so I have little incentive to look at the FSM other than offering suggestions that might help.... many 80s to mid 90s toyotas have kick down cables, electronic valve bodies or not, so it was a generic suggestion

this thread might be more readable/useful to the OP if there's less arguing

MudHippy

No arguments with that. My job is done here.

And FWIW, I apologize if I offended anybody...not really.

Hilux808

Based on your description it sounds like a trans related issue. It sounds similar but opposite to what I was experiencing with my 2000 Nissan Frontier a few weeks ago. Under load, like going up hill I had no power and I would have to sometimes floor it like you do. Instead of not kicking down or down-shifting my problem is that it wouldn't up-shift to the next gear when it was supposed too. The shift points of the trans were off. At first I thought it was a plugged exhaust but like you at low speeds the truck seemed fine and a plugged exhaust would effect the entire power band. Convinced that my Frontier had a transmission problem I finally took it to a reputable shop.

Here's what I would recommend, take it to a shop like I did and have them perform tests on your transmission. Assuming everything else is ok and adjusted properly I'm wondering if your transmission governor is not working anymore. This tells the transmission when to shift based on your speed and throttle positioning. It was the problem I had. Stop spending money on parts until you know what's defective.

Hilux808

Forgot to mention that the governor in my trans is a mechanical device dependent on centrifugal force/speed, newer cars will be electrical/electronic with solenoids. Point being that for you and me, because it's mechanical it will not throw a check engine light. I never had one but driving my Frontier you could definitely tell something was wrong. I'm wondering if you have issues with your trans valve body/shift valves too but a shop can tell you that too if you take it in. Check this link out for a better understanding of auto transmissions...

http://www.familycar.com/transmission.htm

yotarover

dunno if this will help but before i blew a rod. when i replaced the factory hg there was tons of black goo behind the tb. it kept getting worse in power till i cleaned all that *junk* out. this time around on my new engine im using the windshield res to hold seafoam to inject into the tb over periods of time. worked great before kinda like having nos

yotarover

you can buy all 3 of the a340H solenoids here http://www.makcotransmissionparts.com/97420K.html and then buy a rad designs shifter making the auto fun http://radesignsproducts.com/14Shiftcontrollers.aspx

The MAN

since there's no kickdown cable, I'd seriously check all the tranny related sensors first... check the TFT sensor, inspect the shift solenoids (should be able be done outside the tranny), check the TPS (it might not be obvious, but the ECU looks at the throttle position to determine whether to downshift or not), check the output shaft sensor (VSS2?) and the turbine speed sensors too just for the hell of it

MudHippy

I'm not harping on you, but there's no turbine speed sensor or TFT sensor on this transmission either. There's only an A/T OIL TEMP switch/sender, that only turns the A/T OIL TEMP warning light in the instrument panel on/off.

TPS, yes, it's got that.

4runnerRandy

I just installed an auto out of an '87 4runner into my '85 4runner and it most certanley does have a kick down cable, sounds to me like it could be the issue.

worshipmentor

iTrader: (3)

You just have to learn how to take MUDHIPPY.................
His Avatar seems to fit his disposition and often like sandpaper..........
BUT his info is always good.