I have a 1995 Toyota 4runner v6 3vze 4X4 auto trans.
I have replaced the VAF sensor, Starter, O2 sensor before Cat., Recent Tune up.
After installing VAF sensor everything was great. Strong response & acceleration.
The next (Cold) morning I go to start it and it has a very hard time trying to idle.
After it does start idling it will not accelerate past 2000 rpms without missing & losing power.
It will drive only up to 10-15 mph (2000 RPM's) after 15 mph it starts to misfire and bogs.
Yesterday and today this condition would clear up after driving it 15 mph for roughly 10 minutes where I accelerate and make it misfire. One misfire pop and it clears up and runs like new.
I do know that after it has been sitting for more than 5 hours the problem is happening all over again.
I love this truck and it out performs when it runs the way it is supposed to.
Please can someone tell me what the problem is.
I have been looking for the Relays. But what relay and where is it located exactly.

 

My first theory:
Sounds to me like a dirty intake... Is the temp really low? cause this agravates the problem:
Pull the whole manifold , get some good carp/intake cleaner from the parts store (Advance ) and a brush and clean it real good... I work for a Ford dealer during the day and we see this prob every time it gets cold in Louisiana...
(Yes i'm a Toyota trained Ford tech ) < and i work @ advance nights. my life doesnt seem to be that crazy

 

welcome to yotatech ... what brand of o2 sensor did you buy also is the check engine light on ?

 

So, your problems started after installing the new VAFM? It is possible that you damaged one of the intake hoses during this process. Or possibly failed to clamp them down tight enough. If one of those hoses is cracked or slit, it will cause the engine to run like you have described. I would imagine that once the engine warms up a bit, a fine slit would seal itself due to heat expansion. It's worth taking a look at.

 

Wow! You guys have given me other items to look into. One thing that baffles me is how the engine missfire pop clears it up.
I think Yota tech is awesome! I love my 4runner and plan on keeping it until I get put into an old folks home. LOL I will look at those areas of the engine (when I have time) and let you guys know what happens.
My greatest fear is having a cylinder leaking.
Thanks Guys! I'll be back later today.

 

As for the O2 sensor it was the most expensive one out there. I will have to look at the brand.
When it comes to Auto parts I always want the best that I can get.

 

you can get the best O2 sensor from sparkplugs.com An exact fit Denso. That is also the cheapest one you can get. You can order it fromthe dealer but you pay $40 more for it. How old it your ditributor cap and wires. I just replaced my wires with fancy NGK (best fit, no slipping boots aslo from sparkplugs.com) and put an OEM cap on. I was getting some sputtering idle, and that fixed it.

 

I replaced the Dist cap & plugs 150 miles ago. Plug wires I may do this weekend (only time I have to do anything) I know they are getting spark as I tested them last weekend.
This morning I had the same problem and pushed the gas pedal to the floor several times (very fast) and it cleared up. Without a missfire pop needed to clear it up. The check eng lite cleared as well.
Would this be a Throttle body problem? Stuck Flap? You guys are great! I am a Yotatech user forever now. I hope to come accross some of you guys out in the desert of Mojave Ca. sometime. Thanks for all of your responses. PLease let me know if you think it is a throttle body problem.

 

You might want to see what code the engine light is giving you. Sounds like you could have a sticky AFM?

 

OK, I don't mean to hijack this thread -- I have a similar problem whith the POP and rough idle... where's the VAF sensor? I searched for it, but couldn't really find anything useful.

 

Th3duke The VAF Sensor on my 95 4runner is attached to the air filter container. Look it up on an auto parts website so that you know what to look for.
Mine is in the shop now awaiting diagnoses since I don't have a garage to be able to do anything after work. I hate winter hours!
I'm worried sick that it might be a cracked head or head gasket.
I will keep you informed.

 

...or a burnt valve

 

OKay to continue the saga. Shop calls and says "it's your VAF meter" ..."But I put one in last week!" I said. Codes pointed to the VAF. He checked the connections and narrowed it down to the computer unit inside the VAF. I took it back got my money back. The truck is AWESOME!!! again. But I'll tell you. I got more education on my 3VZ notso Ez from Yotatech than anywhere else on the net. I am now saving up to get a long block and take it from there. You guys are great! Chicken Lover. You had it! Thanks one million! Merry Christmas Fellow 4X4 dirtdogs! I will be letting you know if it does that cold morning garbage.

 

The Vehicle (I call it Tommy) is now back to normal. No cold morning struggles. The Volume Air Flow Meter I installed was bad. I found out that knowing how to use a OHM meter on these is very helpful.
Yotatech. Merry Christmas!!!