Lower Intake Plenum cleaning... How to?

[96r50]

Yeah, routing the wire harness through the lower intake definetly was not the smartest move for us having to do maintenance with our 80's but I guess that it made sense to Toyota at the time with the assembly line process for on reason or another.

When I pull my harness out I can look and see how feasible it would be to adjust the hard plastic and tape around the wires so that it comes up just aft of the intake plenum instead of through it.

I'm playing the devil's advocate here (cuz its fun ), but the intake manifold isn't a "serviceable part" designed to be removed as part of regular maintenance. There is no need for Toyota to make it an easy-in, easy-out part, nor is there a reason for them to do so. The clamshell shape of the intake manifold is also a great design in that it protects fragile/expensive/critical/low maintenance parts (wire harness/sensors/injectors/fuel lines/VSVs etc) from clumsy handed grease monkeys such as ourselves .

Next you'll start complaining that the pistons are too hard to get at!

 

[jlg32281]

I'm playing the devil's advocate here (cuz its fun ), but the intake manifold isn't a "serviceable part" designed to be removed as part of regular maintenance. There is no need for Toyota to make it an easy-in, easy-out part, nor is there a reason for them to do so. The clamshell shape of the intake manifold is also a great design in that it protects fragile/expensive/critical/low maintenance parts (wire harness/sensors/injectors/fuel lines/VSVs etc) from clumsy handed grease monkeys such as ourselves .

Next you'll start complaining that the pistons are too hard to get at!

Just because it's Toyota doesn't mean it's perfect. The harness running through the intake is a bad design. And yes, the pistons are too hard to get to.

 

[LINUS]

One possible thing to do is to cut the lower intake, and radius the edges so they won't harm your harness when re-installed. I cut mine nearly 7 years ago & though some have laughed at the idea, it's been just fine.
I popped my HG back then, and when I saw the deal of how they routed the harness I knew my intake was getting cut - I planned it out quite well, I took my time & in the end it was the right call for me.

I say that as a disclaimer - I've also transplanted motors/powertrains into cars that took tons of work, and I have a decent resume when it comes to tools & industrial settings. If you come to the same place I was at, don't worry - it's OK to cut it. The world won't wobble off its' axis, Homer Simpson will still drool & moan his way to a doughnut.

We had a "hotsie" at work that I put to my intake - a little Simple Green and the hot water pressure washer were all it took to make mine sparkle.

 

[S.CarolinaFZJ80]

My current PCV isn't in bad shape and is working correctly, the old one I took out was completely gummed up. I replaced the PCV literally 5 minutes after I bought it. I drove right to the O'Reiley down the street and put in a new PCV before driving it 4 hours home.

The hose was replaced when I cleaned the TB & upper intake out.

The EGR just has carbon in it. It is being cleaned out as well.

Did you verify that the PCV valve was working correctly? If you suspect it's your EGR system you can take a look at the EGR valve & pipe to see they have the same amount of deposits.

 

[S.CarolinaFZJ80]

I'm playing the devil's advocate here (cuz its fun ), but the intake manifold isn't a "serviceable part" designed to be removed as part of regular maintenance. There is no need for Toyota to make it an easy-in, easy-out part, nor is there a reason for them to do so. The clamshell shape of the intake manifold is also a great design in that it protects fragile/expensive/critical/low maintenance parts (wire harness/sensors/injectors/fuel lines/VSVs etc) from clumsy handed grease monkeys such as ourselves .

Next you'll start complaining that the pistons are too hard to get at!

Thanks Adam. Ha ha yeah it is. It's like a Spartan phalanx!

I know it's not serviceable but if it wasn"t for us clumsy handed grease monkeys, there would be no Mud!

 

[S.CarolinaFZJ80]

I got it out ok without cutting or breaking anything. But during the process, I can't say that I didn't atleast think about it.

One possible thing to do is to cut the lower intake, and radius the edges so they won't harm your harness when re-installed. I cut mine nearly 7 years ago & though some have laughed at the idea, it's been just fine.
I popped my HG back then, and when I saw the deal of how they routed the harness I knew my intake was getting cut - I planned it out quite well, I took my time & in the end it was the right call for me.

I say that as a disclaimer - I've also transplanted motors/powertrains into cars that took tons of work, and I have a decent resume when it comes to tools & industrial settings. If you come to the same place I was at, don't worry - it's OK to cut it. The world won't wobble off its' axis, Homer Simpson will still drool & moan his way to a doughnut.

We had a "hotsie" at work that I put to my intake - a little Simple Green and the hot water pressure washer were all it took to make mine sparkle.

 

[S.CarolinaFZJ80]

Here are some pics of my 80 deconstruction. Pulling the wire harness was easier by lowering the crossmember slightly. Once the harness is pulled up and out of the way, getting to the lower intake bolts and 2 nuts is alot easier. As is unbolting the fuel lines from the fuel filter. You'll want to remove the two studs as well and loosen the heater hose that connnects to the head under neath the intake. That way the fuel filter and heater pipe that is attached with will come out as one.

 

[S.CarolinaFZJ80]

Here's what it looks like with the intake removed.

 

[CruiserJack]

I dont know how to do any of this but thanks to great documentation like this I am becoming more confident about doing my own maintenance work.

Thanks!

 

[LINUS]

If you are on your original headgasket, now would be the time to swap it. Seriously, that harness was the biggest skeevie hooker of the whole process.

 

[S.CarolinaFZJ80]

If you are on your original headgasket, now would be the time to swap it. Seriously, that harness was the biggest skeevie hooker of the whole process.

New HG and rebuilt head just before Christmas so I'm good there. The harness really wasn't that bad 15 minutes or so once you create some room between the tunnel and the tranny to extract the wire loom. The connectors were all easy to get to. Just a little dirty.

 

[Houston FZJ80]

I have been wondering where the tranny plugs to the harness are... anyone have a diagram? Looks like a good solution to get a little extra room....

 

[S.CarolinaFZJ80]

I just wanted to up date this thread...
after 11,000 miles and 11 months, the upper intake is still crud free. The oil catch cans DO WORK.

I removed the TRD SC intake runner to gain access to change spark plugs and got a good look at it. There was some carbon from the EGR but that disappeared with some TB/choke cleaner.

 

[uscmas412]

Working on my turbo kit installation. I've got the upper plenum removed. Is it worth it to remove the intake manifold? My turbo installation thread is located HERE for reference.

The engine was rebuilt 1k miles ago and EGR bypassed.

Seems like a catch can may be worth it at a minimum.

 

[fjbj40]

As stated cut the lower intake manifold. It takes 10 minutes and less harm to the heat soaked wiring harness.

I used a pneumatic recip saw with the manifold disconnected from the engine. After removal I cleaned it up with a file.

 

[LINUS]

As stated cut the lower intake manifold. It takes 10 minutes and less harm to the heat soaked wiring harness.

I used a pneumatic recip saw with the manifold disconnected from the engine. After removal I cleaned it up with a file.

View attachment 2335416

Yup. There’s a few nay-sayers but if anybody goes SC/turbo on a mystery gasket this should be SOP at some point.