When I bought my 4runner a couple weeks ago I was told there was a leaking fuel line. The mechanic the seller had look at it said there was a fuel line running behind the engine that was leaking onto the exhaust manifold. He described it as half metal, half rubber hose.

I have her running now and I can't find any leaks. No gas smell and nothing wet I can feel along the fuel lines while running the engine. I'm planning on replacing the valve cover gaskets this weekend so that would be a great time to replace a bad line.

Any ideas on verifying I have leaking line? I can see the lines better once the manifold is off but I won't be able to pressurise the lines.

 

Forgot to mention. This is a V6, 3VZE engine

 

Actually, you can. You're only going to remove the plenum (upper intake manifold) to get to the valve covers, and you won't disconnect anything on the fuel system except for the return line. Use any 10mm hose (I prefer the clear plastic kind; this isn't under pressure and you're only going to have it in contact with fuel for a few minutes) to connect the fuel return from the pressure regulator back to the fuel return on the other side of the plenum. With key-on, engine-off connect FP to B+ on the diag connector. That will start the pump (you'll see fuel flowing through the return line) and you can carefully examine all the pressurized lines.

(Did I mention: have a fire extinguisher sitting RIGHT THERE.)

You might want to just go ahead and replace the flex line on spec (23811B here) for $35. It could be an intermittent leak; why mess with it. Look closely at the Fuel Pressure Damper (23270). It has an internal rubber diaphragm that fails at about this age. Unfortunately, at $112 I would only replace it if you could confirm it's leaking.

To replace the flex hose you must disconnect the banjo bolts. You must replace the crush washers. 23270B, 23807J Don't let anyone tell you you can reuse them. They're about a buck each, but only from the dealership. (same for any other banjo bolt you're thinking of disconnecting)

Last, you don't want gasoline on your hands, do you? Don't use latex gloves; it's scary how fast gasoline dissolves them. Get a box of nitrile gloves (about $8 for 100), and you'll look like a pro.

 

Wow, great response. This is exactly what I needed. I'll connect the fuel return like you said and check for any leaks. If I dont see anything else leaking I will replace the flex line just for peace of mind.

 

I went ahead and jumped FP to B+ with the intake manifold still on, and sure enough the flex line was the one leaking. I'll get the parts ordered and replaced this weekend.

 

Take pictures, report back.

Don't forget to check the Fuel Pulsation Damper.

 

Wow you mean Gasoline is no longer the hand cleaner of choice??( just Kidding)

Those were the days cheap hand cleaner great for cleaning parts.$ 0.45 a gallon .

When it went to$ 0.65 we all thought the world was ending .

Not to many of us left that used gasoline to wash off the block before taking it to the machine shop.