1990 Toyota 4R 3VZE Intermittent start problem

[hadia]

1990 Toyota 4R, 3VZE, AT, V6, 4WD.
For a while experienced with random and intermittent non-start issues about once a week (no klick no crank). Battery new 12.5V when off and 14.5V when running, alternator charging OK and no voltage leakage over time. Replaced Starter. With no more start issues for 6 months, it appeared that it was all fixed until recently that the problem is back so I am looking into Neutral start switch.
From all I read and from the Toyota’s original repair and maintenance manual that I own the removal of neutral start switch was supposed to be a breeze! Based on a few posts, it was suggested to put gear in neutral for removal and in Park for installation. I put the 4R in neutral, removed the mounting bolt and control shaft lever. Opened the washer tabs and removed the 22mm nut. The part wiggles side by side but absolutely refuses to make any forward movement. There is nothing else that can be removed or the manual asks to be removed in order to pull this switch out. What is holding it? Any help is appreciated and thank you in advance. Images attached.

 

[4runner_kid]

Welcome to the forum.

Its probably gummed up from years of dirt and oils collecting on it. I normally use a pry bar very lightly to help motivate it to slide off.

 

[hadia]

Thank you. I was not sure if it is just dirty and gummed up or there is a mechanical trick involved in removing it. I sprayed some W40 on it and will try it again tomorrow. Thanks again.

 

[4runner_kid]

Thank you. I was not sure if it is just dirty and gummed up or there is a mechanical trick involved in removing it. I sprayed some W40 on it and will try it again tomorrow. Thanks again.

Not a problem.

 

[hadia]

Yes, it was just stuck. DW40 helped and it came loose but leading to a bigger problem. There is a metal hose running in front of it and the valve shaft runs all the way to the hose. I need at least another inch of space to slide this part off the valve shaft. What do this metal hose does? Should I mess with it? Should I be expecting oil spillage if I open it? The Manuel does not show or speak of this hose at all for Neutral Safety Switch removal!

 

[4runner_kid]

Yes, it was just stuck. DW40 helped and it came loose but leading to a bigger problem. There is a metal hose running in front of it and the valve shaft runs all the way to the hose. I need at least another inch of space to slide this part off the valve shaft. What do this metal hose does? Should I mess with it? Should I be expecting oil spillage if I open it? The Manuel does not show or speak of this hose at all for Neutral Safety Switch removal!

That is in fact a cooler line. Just loosen it up and move it out of the way. Yes there will be oil spillage from said metal line.

 

[hadia]

It was difficult to access any of the bolts and nuts and little room for ratchets to move. I ended up bending the 4 inch wide bracket that was across the switch and got plenty of room for my hand and tools.
Disassembled, cleaned and rubbed a touch of dielectric grease on contacts, reassembled and mounted it back on the transmission. Hopefully, my intermittent non-start problem will be a thing of the past. Will report how it goes after a few days of driving. Thank you 4Runner Kid for being the lone helper on my thread. I very much appreciate that.

 

[4runner_kid]

Hey man not a problem. On this forum i've noticed alot of people don't speak up if they don't know the answer. Anytime i can help i try to. Report back with us and let us know.

 

[RAD4Runner]

Good job, cleaning the NSS.
Even after that I believe the cranking circuit still has a problem, because it does not have a starter relay. Explanation and fix are here:
http://www.toyota-4runner.org/class...d4runners-mods-restoration-7.html#post2182599

 

[hadia]

Thank you Rad4Runner. My 1990 4Runner has a Starter Relay and the problem with my start was that I wouldn't even get a click before the crank part. One of the initial troubleshooting I did was I removed the relay and verified OK per Toyota Manuel test instruction. Non the less, thanks for the extra info. The thread link you provided has lots of interesting and useful information. Hopefully cleaning the SNN will fix my problem.

 

[hadia]

So far the 4Runner doing alright and no Start issues after the Neutral Start Switch cleaning.

But, I have not changed the transmission fluid on this car and the mileage is close to 200K. I want to do a transmission fluid flush but the mechanic says because you haven’t done it for so long, if you do a flush your transmission may start giving you problems. Is he correct or just does not want to touch it because he thinks it might be to dirty to flush and clean? Except for the Start issue, I have never had nor have any transmission problems and the 4R is running fine. Any comments? Thanks.

 

[4runner_kid]

So far the 4Runner doing alright and no Start issues after the Neutral Start Switch cleaning.

But, I have not changed the transmission fluid on this car and the mileage is close to 200K. I want to do a transmission fluid flush but the mechanic says because you haven’t done it for so long, if you do a flush your transmission may start giving you problems. Is he correct or just does not want to touch it because he thinks it might be to dirty to flush and clean? Except for the Start issue, I have never had nor have any transmission problems and the 4R is running fine. Any comments? Thanks.

Being the mechanic that i am, i would say he is correct. It may start giving you issues after a flush if a service has never been done. I would just do a service on it and no flush.

I have had it happen on customer's car, where i do a flush and the transmission would start having shifting issue's. However there is time's where it doesn't affect anything. It's really up to you the customer if you want to take the chance.

 

[hadia]

4Runner Kid, somehow I did not receive notification on your last post. I did the transmission flush.
As far as the start problem, it acted up again today, after 360 miles and exactly a month after the Neutral Start Switch clean up. Nothing new, same old sudden non-start issue. It started again after 15 minutes!

 

[4runner_kid]

4Runner Kid, somehow I did not receive notification on your last post. I did the transmission flush.
As far as the start problem, it acted up again today, after 360 miles and exactly a month after the Neutral Start Switch clean up. Nothing new, same old sudden non-start issue. It started again after 15 minutes!

Did the flush help? Maybe you should look into buying a new neutral switch.

 

[hadia]

I have not felt any difference in performance since the transmission flush. As far as the non-start problem goes:

_Battery is only 2 years old and all suggested battery tests are OK and no overnight leakage on the voltage.
_Start Relay was tested OK per Toyota manual instruction.
_Alternator was tested OK per Toyota manual instruction
_Starter was replaced in February. (after starter replacement, I had no start problem for 6 months and I thought that the problem was gone for good)
_All connectors and wirings as far as I have been able to reach and check are secure and tight.
_Neutral Starter Switch cleaned and made no difference. If there was a sure bet that this is still a problem I would replace it.
_Fuel injectors and spark cable were replaced 2 years ago (not for this problem but I thought it was time to do it)

This problem is so intermittent and that is a problem by itself. It does not fail when I take it to mechanics and therefore they just guess what might be the cause just like I guess. The Blue Book value of this car is non-existent and I am wondering how much($) more to spend on this one problem. At the same time this 4R is my life line and can’t afford a replacement.

I remember old cars had a voltage regulator and very accessible under the hood. That is something I have not looked into. I have no idea yet if this 4R has one and where it is located. I have to dig into that.

 

[RAD4Runner]

Your voltage regulator only affects charging, not cranking.
Pls post schematic of ur starting circuit AND CLEAR picturs of ur starter relay and wiring.
Clear high resolution pics.
That problem is EASY to fix if u help put us at ur vehicle.

 

[hadia]

When the problem happens, I won’t even hear a click, though in last episode which is post Neutral Start Switch cleaning, I heard the click when I attempted to start. It won’t go any farther than that. It won’t get to cranking part at all, otherwise a lot more parts will be suspected I assume. Attached is a wiring diagram I got from the manual.
I think I did the best to check the battery (measuring at off and at on positions, turning headlights on and checking for dimming out, monitoring for voltage leaks, etc…),and all look good, but if there are other steps to verify the battery I appreciate it if someone share them with me. Thank you.

 

[RAD4Runner]

When the problem happens, I won’t even hear a click...

Tnx for the schematic.
You problen is almost solved. $30 and a little work will fix that.
That truck has the wiring flaw covered over and over on both Yotatech and T4R.
You need to ADD a starter relay. Search my post, OR see KidVermicious ultimate fix.
The manual trans version of that truck was wired WRONG AT THE FACTORY.
See Griswald's fix.

 

[RAD4Runner]

When the problem happens, I won’t even hear a click...

Tnx for the schematic.
You problen is almost solved. $30 and a little work will fix that.
That truck has the wiring flaw covered over and over on both Yotatech and T4R.
Search "clicknocrank"

You need to ADD a starter relay. Search my post, OR see KidVermicious ultimate fix.
The manual trans version of that truck was wired WRONG AT THE FACTORY.
See Griswald's fix.

 

[4runner_kid]

Tnx for the schematic.
You problen is almost solved. $30 and a little work will fix that.
That truck has the wiring flaw covered over and over on both Yotatech and T4R.
You need to ADD a starter relay. Search my post, OR see KidVermicious ultimate fix.
The manual trans version of that truck was wired WRONG AT THE FACTORY.
See Griswald's fix.

I have NEVER had to add a starter relay and i have owned at least ten, 5 speed model's. I've never even heard of this. But if it work's it work's.