jochumson

91 4runner with a 93 3.0
When it is cold only, it will start and run really rough shooting carbon or fuel out the tail pipe but if I keep the RPMs to about 3000 it will smooth out and run good for a about 4- 8 min. then if I back off the RPMs it will die and will not start until it is cold again 4 to 5 hours.
I have changed the:
ECM (computer)
Plugs
Plug wires
Distributor cap
Distributor
Coil
Igniter
Timing belt
Fuel filter (after it ran great for about 10 seconds then died)
Cold start injector
and I unbolted the catalytic converter and ran just the pipe
All of this with no change!
The deal is that I live 80 miles from the nearest Toyota dealer. After I paid them for some advice on what the problem might be they said that it was the timing. So that is why I have replaced all of the timing parts. The other parts I replaced because of suggestions from others. So I am now onto the fuel parts and the VSVs. It just happened that an old man that lives near me forgot to put oil in his 90 4runner for 2 years and… well sold it to me for a few hundred so I have parts however I would love to know which parts I should be working on. I am looking for Toyota genius.

By the way I took it to a local shop and after a month they suggested that I pay the $800 to have it taken to the Toyota dealer. Are you smarter than they are?

thook

Coolant temp sensor.....probably.

Kiroshu

Is it running really really rich or just alittle puffing. If its running that smokey and rich you may need some piston ring replacment. Some people call them piston seals but like any part they wear out sometimes. They are more less a seal or ring around the piston that keep the oil from going in to the cylinder where your gas is being fired. You may have some of those just bad or completley eroded. It happens. You can check that. I know thats a hasel but it might be your prob. You said you replaced the fuel filter. Maybe flush out the fuel system sometime. You can try sea foaming it I have heard many good things about sea foam. It should give it a bit of a clean. Mind you when you use sea foam its desgined to smoke when you start it up becasue it trying to burn away the sea foam. Dunno if you have used it or not but yea. Are you going to the same gas station everyday. You maybe going to a cheap gas station with really garbage gas. There is a thing as cheaply made gas. With all kinds of impuities and left oil and stuff. Check it out and hit me up. Oh and check your air filter.
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95 Toyota 4runner SR5 V6 3.0 Automatic 150,000 Miles

mr_schuster

I think he means the coolant temp sensor for the EFI.

Kiroshu

His EFI is prolly fine. Nothing much happens to them unless they get clogged or dirty then you may have to clean them or in worst case rebuild them. But it should not be that. That would not really cause smoke unless the timing is incredibley off, but he said he fixed and replaced all the timing stuff.
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95 Toyota 4runner SR5 V6 3.0 Automatic 150,000 Miles

Flash319

I would say;
first, coolent temp sensor
second, TPS (throttle position sensor)
Third, AFM (air flow meter) is stuck.

Sounds like you have a rich condition. I would have first said cold start injector but you changed that.

DeathCougar

iTrader: (23)

x2

Get a FSM and check resistance readings in the sensors on the back of the engine. That will tell you if its a temp sensor.

Was the cat getting red hot?

rdharper

Did the problem come on slowly... or did it magically appear one day?

If it came on slowly, I'd be suspicious of the VAFM as others have said.

Also, if you know how to use an ohmmeter, get the FSM and make the checks. Or if you have a replacement, swap it out.

thook

You're thinking of the injectors? EFI...the term....encompasses more than just the injectors, though. They're one part of an "EFI system". The coolant temperature sensor (not the sending unit) also being one part of the EFI system....which, btw, can and does affect the timing. Like the TPS, AFM, O2 sensor, etc. all to a degree.

AH64ID

Not sure how many are on the 3.0, but a 22RE has 3 IIRC, at least two... I had one going out (one of the EFI ones, not the dash gauge one.. so no indication) and my truck ran rich as crap... lost 2-3mpg....

I also had a similar rough idle with a bad vacuum hose.....

loacyota

The 4 runners have had enough problems with the head gaskets, just for shoots and grins check compression.

thook

There's only one for the EFI on either of my 4rnrs. Then, there's the temperature guage sending unit. That's all that I know of on the first and second gen 4rnrs. That's all the FSM point out, as well....that I've seen.

AH64ID

Yep... the 3rd one I was thinking of is the Start Injector Time Switch... whatever that does... .

thook

Hahaha....right...that one. "Cold" start injector time switch for the cold start injector....so's the ECU can tell the cold start injector when to squirt some gas. It's a different circuit than the water/coolant temp sensor.

Kiroshu

ya I know. you know what I mean most people talk about the injectors in EFI
alot o things can be in account here but its prolly not as serious as most of you thing.

94svt50

I second the headgasket. In a catastrophic blow, the steam blowing out the tailpipe might look like smoke. Had it happen on a v6 stang one time, white out conditions.

thook

Coolant temp sensors are little less serious than rings, though......don't you think?

However, you're right. It could be several things. That's what bugs me about EFI.

jochumson

I did replace the Coolant temp senor before I had this problem because the plug fell off however it ran fine before I was able to change it just the code in the computer.
The compression test gave me 145 on all cylinders. There is no coolant in the oil. Is there anouther way to tell if the head gasket is blown. They said that they replaced it when they put in the 93 3.0 off the recall.
The exhaust smells like gas. So it is running really rich.
Today I will go out and check Coolant temp senor with the ohmmeter and check all the wires.

I really want to thank everyone for posting there suggestions this has been a very long battle going on 4 months and I have only owned this 4runner for 6 months. thank You!

ozziesironmanoffroad

145? id think that was a little low... but if theyre all even, then i guess u got no prob... if ur lookin for a toyota genius, i think you came to the right place..

jochumson

It was the Coolant temp sensor. It turns out that the new one was messed up. I puled the one out of the 90 4runner plugged it in and started right up and ran great for about 30 min then I put it in gear to give her a drive and she died.
I looked at the throttle position sensor and it was a little loose. How do I adjust it and know that it is in the right spot?
What is the best way to get the timing on perfect?

I cant thank you guys enough you have no idea the hell I have be through. You can imagine the money I have spent.

Thank you