Solved: 2TR Rough Idle

I've been chasing a rough idle for about 3 years now. I attributed it to draining my battery camping at high altitude camping then switching over to my backup and resetting the ECU.

The coolant bypass just went and after replacing it the truck wouldn't idle. It would back fire and try to sort things out but would eventually just quit. I ordered new throttle body and manifold gaskets, tore everything back apart then found a cracked vacuum hose. Heat shielding was covering the split.

The hose that's cracked is on the firewall side of the manifold. It's about 2" long and goes from 5/8" to 3/8". No idea what it's for and I can't find it on any Toyota parts diagrams.

I was able to heat up then jamb some 3/8" vac line on there to replace it. If anyone has actual part number please comment. From what can tell Toyota hacked this too as this hose has kinks in it from the factory and the hard aluminum tubing it ties into looks like it was beaten with a hammer.

This is on a 2007 so things may have changed since. Below is the bung where the hose attaches.



If you're doing a coolant bypass... Order the manifold and throttle body gaskets!! Also have 3/8" vac tubing, heatgun, and hose clamps ready.

 

Toyota hoses have metric inside and outside diameters.

 

Do you know the part number or hose sizes? I'd like to replace this chunk of SAE hose with the metric equivalent.

 

Here you are

 

Also, welcome aboard

 

Thanks OP, for sharing these tips for the rest of us with a 2.7l plastic coolant by-pass hose that may have the same problem you did.

 

Lol i am so with you on this. Such a stupid design. Let's make this very difficult to see and install with the intake manifold on, and then let's go ahead and make the ends different sizes so we can really frustrate people