replaced valve cover gaskets - truck wont start

This is in reference to my 3rd gen 4runner.

I am posting in first gen Tacomas because as many of you know, the engines are the same and many of the parts between 1st gen Tacomas and 3rd gen 4runners are interchangeable.

So here is my issue, which I will explain with much as much detail as possible.

I replaced my valve cover gaskets last Monday. First time ever doing it, took me all day. When i work on my vehicles, i like to take my time, being careful with everything i do.

Once i put everything together, the 4runner wouldnt start.

It would take me two or three tries to get the truck to start, when it would start, it would rev up to 3,000 RPMs, and turn off. Nothing more. Every, single time.

After a few tries, i noticed there would be a faint thump - Like air pushing out.

I also noticed the check engine light turned on. So i ran the codes:

P1120 - Accelerator Pedal Position Sensor Circuit Malfunction

P0120 -Throttle/Pedal Position/Switch "A" Circuit Malfunction

P0115 - Engine Coolant Temperature Circuit Malfunction

P0110 - Intake Air Temperature Circuit Malfunction

P0100 - Mass or Volume Airflow Circuit Malfunction

I knew that i either didnt connect something OR i left something unplugged.

I took everything apart, checked my connections.

BAM -

My Connections:


The correct connections, per @willhaman21


I had accidentally plugged the PCV hose into the black airbox and the black airbox hose into the PCV valve.





Well I went ahead and swapped them correctly.

I disconnected the battery for about 30 minutes to clear the codes and tried turning the 4runner.

Nothing.

The 4runner turns on, sputters off.

I still hear that faint thumping noise.

Codes cleared and stayed off. Didnt come back on.

I am at a loss here, i feel the only path forward is to take everything apart and check again for any more loose connections, hoses, etc.

Did I screw anything up by trying to start the truck with the hoses connected incorrectly?

 

MAF plugged in?

 

yes

 

There is a plug under the throttle body, is it plugged in?

 

under the throttle body?

or ON the throttle body?

 

Underneath the rubber intake hose but on the throttle body, my bad.

 

There is one plug at the right for the accelerator cable.

Two on the left one is for TPS and the other below it, i dont know.

There is an air hose connection on the upper left pointing down

Two coolant hoses connections

 

If im looking at your previous pictures then yes it appears to be plugged in, but im not sure what im looking at in that pic above. If thats a 5vz then ive never seen that tb before

 

in that picture, im showing you the available connections on the throttle body itself

 

Originally I had accidentally plugged the PCV hose into the black airbox and the black airbox hose into the PCV valve.. .

i wonder if that screwed anything up

 

I see. Welp I have no clue honestly, its even weirder you are poppin all those codes at once...

 

@Tacoma Mike , any ideas?

 

well theyre cleared already.

 

Possibly actually, that hose that you plugged into your PCV should have been your fuel pressure regulator hose. The vacuum it saw may have destroyed the diaphragm. Although it shouldn't have.

EDIT: Nevermind there's no vacuum at the pcv...

 

this is the 5vz also...

Yes, that hose runs to the fuel pressure regulator i believe..

 

How can i test the fuel pressure regulator?

 

There shouldn't be any vacuum at the PCV sorry my mistake, the pcv just emits a little pressure and I doubt that did anything...

 

I believe this, correct @Brice