JKWHSU

Greetings,

I'm new to this forum, please bear with me.

I have a 2004 GX470 that needed the engine replaced. I went to automotix.com and bought an used engine with 70,000 miles from them. When the engine arrived, it was a 2003 4.7L from a toyota 4runner. They told me that the 4runner 4.7L is the same engine in the 2004 GX470. I had a local mechanic try to install the engine. He took my old engine out & installed the used 4runner engine.

He then tried to connect the plugs and noticed that my GX470 had 10 (ten) connections, but the used 4runner engine only had 9 connections. He connected the first 9 connections and left the 10th plug open and tried to start the car, but it would turn over. He's not sure how to make it compatible. He and I are researching on what to do next.

My question for those of you with experience installing the 4.7L 4runner engine into a GX470, how to you get all the connections hooked up. Is there an adapter? Please help.

thanks,

Joe,

ROK

I'd be more concerned as to why you're mechanic doesn't know what to do. If no one here has a simple response, I'd consider taking the truck to your local Toyota dealer.

gl with it. It's gotta be a crappy feeling when things aren't panning out especially with an useful thing like a utility car.

Ancient

Don't you have your old gx motor, to see where the 10 connections went to?, or did you have to return the core for credit already?

I have read most of the posts on this web site and not heard of anyone doing this. There must be an extra sensor/ component on the gx motor. Other than having a gx wiring diagram, you would need to look at another gx.

Even if it did start, you might start getting codes right away, since one harness was not connected. Here is where I sound stupid, you know that there is an immobilizer switch, next to the gear shift on the console. small square cap. Read owners manual about the sequence/ function of that switch. You may have to reset it.

Sweep

depending on what was wrong with your old engine there are a few ways you can remedy this. I am guessing that the block is bad, so I would only swap the block, then put the original heads and all on this new block. that should give you all of the original connectors. But I suspect that you have something else going on.

mann777

Has the ECM also been swapped.

06isDriver

the tundra 4.7 and the gx 4.7 are slightly different animals. I'm sorry I dont have any help for you but this answers an additional question of what differs between the two.

I'm guessing you wont need premium fuel anymore, if you can get it running. I'd imagine you'll need an ecm swap, too.

ROK

He said 4R, not Tundra. It's the same engine. The switch to VVTI occurred with the '05 models in the GX line.

4R also recommends premium fuel on their non-VVTI 2UZ-FEs.

JKWHSU

Excuse my ignorance, is the ECM (engine control modules), the wiring that connects the engine to the car computer system? Can my mechanic use the old wiring harness from my original GX470 engine and will it connect with the used 4runner engine?

Ancient

Normally, one would disconnect the GX wiring harness, at the engine, when they remove the engine. They would not remove the engine with the wiring harness too. They would only remove the engine.

tissimo

Swap the GX wiring harness over to the 4Runner engine. I did this on my GX as I bought it with a bad engine. I put a 03 Tundra engine in, swapped the oil pan and the wiring harness over and worked like a charm.