help me identify this black box and random engine dying

[69LC]

My wife recently picked up a 96 4 runner for our daughter to drive and it has a few things going on.

First of all, this black box between the fuse box and firewall makes a weird buzzing sound-on and off again.

Also, the truck recently started running out of power so it can't be driven. It's a 3.4L v6, auto. I just replaced the inline fuel filter and thought it was doing better until a short test drive. After I got the truck to sputter back into the driveway i put it into neutral and was able to get it to rev sometimes.

I've read a few different ideas here and on Google about what the issue could be. How likely is the IAC the culprit? Also, how likely could it be the fuel sending unit getting weak? I didn't find any cracked or broken vacuum lines.

I've barely spent any time with the truck yet and have most of my 'Yota time with my 40 and my wife's 80. This is a new animal to me.

 

[Mudder]

Evap box. don't remove it unless you want to fake out the system so the ECU believes it's still there.

 

[69LC]

Could the evap box make a buzzing sound like i described after turning off the engine?

 

[69LC]

I've been doing lots of searching with other forums, Google and whatever comes up. there are lots of random ideas about what could cause the engine to cut out during driving. I'm not seeing anything here related when i use the search option.

It sounds a lot like a random electrical short based on other's similar experience, but then theres ideas of VSVs, loose gas cap or bad seal, fuel system components (I know the pump and filter work), ignition modules, relays, position sensors etc, but nothing definitive.

I could really use some quality help.

 

[69LC]

I know no one is responding, but I'll keep trying.

I just replaced the EFI relay. Prior to pulling the truck into the barn it would barely run. I had to floor it to start and then cycle the pedal quickly to have it stumble up the slight step in.

After the relay switch, it will run if i give it some pedal while starting and then run fine. It will run the AC. If I try to start it without pedal, half the time it will start and not the other half.

Also, It will stumble and die if I put it into gear unless I hold both pedals to keep more fuel to the engine. What am I chasing? At least I can drive it onto a trailer to take to a mechanic if I need to...

I'm currently letting it sit and run to build some internal heat. No idea if it will help.

 

[bigredmachine]

black box is the charcoal canister, probably shouldn't be making any noise. not sure why it would be making noise but there are internal valves inside that could be the cause.

as for the iac, possible but usually you would have more of an issue when cold and not at operating temp. its easy enough to remove and clean but cleaning is just a temporary fix. cleaning the throttle body would be a good place to start.

how do the plugs and wires look? is the cel on

 

[vipergrhd]

The noise you are hearing could be your purge solenoid, the evap canister is contained in the box and vacuum hoses are connected to it. Check for vacuum leaks on all your hoses including your intake tube hoses clean your MAF sensor clean your TB. Pull your spark plugs and inspect and while your at it do a compression test. Don't do anything to your IAC until you have checked all your basics if you can check your fuel pressure too. Post up if you have any codes and take a pics of your plugs. Good luck on your quest.

 

[69LC]

I gave up yesterday and hauled it to a mechanic I trust. My son also blew his car up on the way to school. While I was loading the 4 Runner behind the 80 my daughter told me the basement was flooded again...

I'll let someone else handle this one.

 

[vipergrhd]

@69LC keep us posted on the findings.

 

[69LC]

I will. It seems like a lot of people have similar issues without a good answer.

 

[vipergrhd]

I forgot to mention check out T4R.org if you get the time. They are more dedicated to 4Runners,great group of guys like mud.

 

[bigredmachine]

Could the evap box make a buzzing sound like i described after turning off the engine?

there is a tsb for an updated hose going into the canister to eliminate a buzzing noise, if you need it I can look it up again and give you the updated part number

 

[69LC]

That would be great. I have to reach out to the mechanic anyway. Maybe I can get him to throw that in too.

 

[vipergrhd]

Any finding on what's going on ?

 

[Kleatus]

FWIW our 96 has always made the noises you describe, mostly in hot weather. I figured it was normal evap stuff and never messed with it. That's the one vehicle we've had the longest and I know the least about-never had to mess with it!

 

[69LC]

It seems that the front O2 sensor was the issue.

 

[vipergrhd]

^^^ Install a Denso.

 

[bigredmachine]

p/n 77701-35010 evap canister hose no1. it was updated to include an air chamber attached to the hose. it would be installed on port e, that should eb the port closest to the fuse box.

 

[69LC]

Thanks for the input. I don't know which brand of O2 sensor he used, but the truck runs great now. Now for better winter shoes...

 

[69LC]

So my daughter took the truck out to get groceries for the first drive since the fix. She took the worst area road and hit the normal snow pack to end up doing a 180 across the road into the field on the other side of the road. She didn't roll it, but packed sand into the right rear bead for the tire to go flat.

She ditched our old Elantra in the same spot two years ago.