Air intake manifold / EGR service? Pic heavy! (1 Viewer)

[lechnito]

My 1990 FJ62 has always idled a little high at 900 - 1000 RPM for as long as I've owned the vehicle. So I started a project this weekend to clean out my throttle body and recalibrate the throttle position sensor. Turns out that the throttle body was already pretty clean but the air intake manifold and EGR valve were filthy:

I also noticed some carbon material splattered on the outside of the intake manifold around the EGR vacuum modulator assembly. There's been a mild burning smell when I drive for long distances and I wonder if this is the culprit.

So my questions are:

1. Is there any benefit to disassembling my air intake manifold and EGR system for cleaning? Should I just clean the EGR components? Or should I just put the truck back together because this is a rabbit hole from which few souls return.
   
2. At nearly 200k miles, the fuel injectors should probably be serviced. Can the injectors be removed while the air intake manifold is still in place?
   
3. Likewise, can I service the cold start injector without removing the air intake manifold? It takes a second or two of cranking before my rig starts up.
   
4. Is it possible to service the EGR vacuum modulator or should I think about buying a new one at this point?

Thanks mud bros!

 

[sbelinge]

My first thought would be for you to give the guys at LCNW a call. They would be able to give you good advise about how to proceed and if need be, they are a great shop to take your rig to.

Cleaning out the carbon is always a "good thing" but not always easy or quick. It really depends on how bad it's running, how much time/money you have, and how confident you are digging into the engine. The cold start injector is super easy to take out and clean, maybe a 30 minute job. The rest of the ERG/smog stuff is pretty old and I don't know about servicing individual parts. When mine started to go bad I decided to desmogged it.

 

[Output Shaft]

Just replace the EGR modulator. It's relatively cheap. Then you'll have your old one as a spare.

Yes EGR valves can be cleaned up with Mr Muscle Oven Cleaner and some small SS pipe brushes. Nice to have a clean EGR valve that doesn't stick. Don't get the MM on the EGR diaphragm.

But high idle isn't caused by cruddy EGR components.

 

[lechnito]

I think I'm just going to clean the cold start injector, EGR valve, and replace the EGR vacuum modulator. I'll leave my air intake manifold in place and worry about my fuel injectors later.

@sbelinge Were you able to pass emissions after desmogging?

 

[sbelinge]

@lechnito I don't have to do that anymore. At 25+ years old it's exempt in WA. Though I do plan to keep all the old smog equipment.