Advanced 3vz Trouble - Experts please help

Hi All,

I just completed a head replacement, including all the related headaches, on my rig (see below). It took me forever, as I am a hobbyist with lots of cool tools, not a mechanic with lots of knowledge.

I have a strange symptom - The engine runs smooth and I am generally very happy with the repair. However, after the engine warms up, I get a terrible sluggish, bogged down feeling when accelerating. This happens usually in city driving, so I suspect tranny stuff. I bought this truck new in California, so it is full of CA smog stuff. I almost always find problems with vacuum, but this one is perplexing.

Here's the best part: If I turn off the motor - even for a couple of seconds - it starts right up and runs smooth with no hesitation.

Any ideas?

Thanks in advance

The computer resets and rechecks the sensors when you restart. Maybe it has a bad sensor. I would check the codes. To check them pop the diagnostic cover and connect two terminals. I believe they are labeled TE1 and E1. Stick a paperclip between the two and the check engine light will flash the codes.

Thanks for joining in, Tom.

I am familiar with the procedure for retreiving codes. I didn't think that I could get a code if the OD OFF light wasn't flashing.

I'll try it anyway and let you know.

Thanks,

Since the problem is heat-related, you might consider looking at the engine coolant temperature sensor and seeing if it is within spec.

Thanks - I am working thru an EGR error code right now. I hate that block of hoses and electrical connectors at the back of the engine block up against the firewall. Every procedure is a hassle. Of course, that's why my problem is likely to be there :)

Thanks,

Problem solved.

I replaced every stupid little vacuum hose on every smog-related component.

viola - it runs great.

Hope this helps someone else.

Thanks,

Did you notice if any of the hoses were loose or cracked? If you could pinpoint the likely problem hose, then it would be of more help. Your symptoms would not be caused by a simple vacuum leak. It must have been a switching or signal hose.

Hello All I could use some help with those nasty vacuum lines. I have a 95 4Runner with the 3vz engine. I recently re-installed it after a rebuild for a bad piston. I reconnected everything the way it was the problem is
that it was wrong to begin with (bought used a year ago). The Chiltons
is worthless and the underhood diagram is incomplete. Here's the problem, No hoses are connected to the switch on the power steering
pump, a hose comes from the fender wall but goes no where. I confirmed the ones that are on the diagram but many others are unknown.

Also, as it warms up the idle drops to 250 rpms or less. Anyone know
anything about the idle circuit? I suspect that this and the vacuum
issues are related but not quite sure.

Any help is greatly appreciated. A diagram would be fantastic!

Thanks,

Tim

Hello All I could use some help with those nasty vacuum lines. I have a 95 4Runner with the 3vz engine. I recently re-installed it after a rebuild for a bad piston. I reconnected everything the way it was the problem is
that it was wrong to begin with (bought used a year ago). The Chiltons
is worthless and the underhood diagram is incomplete. Here's the problem, No hoses are connected to the switch on the power steering
pump, a hose comes from the fender wall but goes no where. I confirmed the ones that are on the diagram but many others are unknown.

Also, as it warms up the idle drops to 250 rpms or less. Anyone know
anything about the idle circuit? I suspect that this and the vacuum
issues are related but not quite sure.

Any help is greatly appreciated. A diagram would be fantastic!

Thanks,

Tim


Yeah,yeah....know this is late but to those in same situation....keep eyes peeled on used car lots and neighbors that have same vehicle and ask to look at their setup and compare to yours (a six pack or lunch along with a promise not to disconnect or remove anything usual works)

Hi All,

I took many digital pics of the vacuum hoses when I did the head gaskets earlier this year. My rig is from CA, so there are some additional smog hoses.

I am out of town, but when I return (Sunday night) I'll try and post them. I have never done that before, so some tutoring would be helpful.

Hope you can wait.

David