4Runner won’t stay running

Me and my friend recently bought a 1994 4Runner and it will die as soon as I start it up unless I have my foot in the gas pedal. Im wondering what can cause it to do that and how to fix it. I’ve got the 3vze engine

 

could be a lot of different things... MAF sensor, timing sensor, bad gas, timing is off on the cams/ crank, multiple mis-fires vaccum leak, plugged exhaust... the list could be very long or it could be something as a connector not on all the way. is the Check Engine light come on when you are able to get it to run?

 

I got a code 22, Engine coolant temp sensor which the previous owner had broke off so we got it replaced. Also got a code 24 but I don’t know where that sensor is located.

 

What is the name of said sensor so we can help you locate it...

 

Intake air temperature sensor

 

Usually on the back side of the intake manifold. 2-3 wires on the connector. Seen a few go bad but only causes the engine to run rich but not cause them to "not run." But there is a first for everything....

 

The intake air temp sensor is in inside of the VAFM. Here is a link to an article to test the circuit. These readings are for the 22RE, but they are probably similar for the 3VZE. You want to measure the resistance between THA and E2, it should be 2K to 3K ohms resistance at 68 degrees F. If the circuit is open or the resistance is way off, that will trip a code 24.

http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml

Let us know what you find.

 

While fixing those sensors is good, I don't think they will be the cause of it not running at idle.

I'm thinking a vacuum leak or bad gas. Might be a bad injector or 3. Or like was mentioned...a bunch of things.

How well does it run when you have your foot on the gas?

How much do you have to rev it to keep it running? Or do you just need a small bit of extra throttle to keep it running? Can you keep it running indefinitely or does it fight you?

White or black smoke out the tail pipe?

Pull the plugs and see what they look like.

 

Does it only happen when it’s cold ? Could be the cold start injector

 

It seems to be running lean. We’re replacing the fuel pump and fuel filter this weekend if we have the chance. I had read somewhere else that sometimes they don’t start on the cold but I have no way to see if it’s due to temperature since it’s just been freezing for the past couple months

 

If I’m not mistaken they have a cold start valve it’s called check into this I may be wrong

 

This is cold start valve

 

Had the same problem when I had my 1st gen Runner. Turns out it was the TPS, ( throttle position sensor ).
Sounds like that might be your problem given the fact that it will keep running if YOU throttle it.
As I said, mine was acting the same. It was the 22re, but, might be similar enough.

 

Hi:
That picture is showing the cold start injector.
The CSI will inject extra fuel during the cranking phase of a cold start.
Once the engine starts, and runs, the CSI is no longer in play.
The symptom of a bad CSI is a long cranking period till you achieve engine run.
Once the engine starts the CSI is no longer needed, and is automatically disconnected by the VAFM, (the round thing with the air filter in it) and the COR. (circuit opening relay)
Good Luck.
Art.

 

We finally got the 4Runner to stay on without giving it gas. We replaced the fuel pump and fuel filter but it would still stall. Replaced the air intake hose because it was falling apart and now the truck will stay on without giving gas but it runs rough. Also discovered an oil leak coming from the engine