Clogged EGR Passage on the Intake manifold

[Ian R.]

Hi all, I have been trying to track down an issue with my ERG after failing smog. I was commenting on another thread but I believe I have found the issue. All the EGR components check out and are working. But I think the EGR passage on the intake manifold is plugged.

I was able to get a tight fitting hose into the egr passage on the intake manifold. I am not able to blow air through with the engine cranking. I think it might be plugged up good. Is there a way to clear the passage with out taking the intake manifold off?

Thanks!

Ian

[Ian R.]

I am happy to say I figured it out. Below is a diagram with where the exhaust gas runs from the EGR, through a channel that is cast in to the manifold (drawn in red), and exits into the intake manifold. The exhaust exits this channel into the manifold directly right and behind the opening where the throttle body mounts. Mine was so badly clogged I could not even tell that there was a roughly 3/8 diameter hole there ( i should have taken a picture).

Here are the steps I took to clean the EGR channel. First I removed the plug bolt highlighted in yellow, and plugged the EGR inlet (highlighted in blue). Next I poured carburetor cleaner into where I removed the plug bolt (yellow) till it was brimming, and put the plug back in to keep the solvent from evaporating. I let that sit for 4 hours. Next I tucked a sheet of plastic through the throttle body inlet that ran beneath the EGR channel hole exit, and wrapped up, this formed a little basin to catch any particulate that fell. This kept all the crud from falling into the intake. Then, using a flat head screw driver I got the hole started. At the start of the hole the built up was hard, but as I excavated towards the back of the engine it started to soften up. Next I used a wire gun barrel brush connected to a long piece of rubber hose that was small enough in diameter to fit into the EGR channel. Using the rubber hose was useful because it could be advanced down the ERG channel even after making a 90' turn. Additionally the gun barrel brush has a threaded end that conveniently screwed into the end of the rubber hose, keeping it from falling off when I pulled the rubber hose out. I rammed this back towards the back of the channel. After this, I unplug EGR hole (blue) and attached a rubber hose that fit tight in the EGR hole (blue) at the back of the manifold and blow through it. A nice little turd plopped out into the plastic sheet basin and the EGR channel was clear. I spent some more time cleaning up the channel as best as possible.



I ended up damaging the ERG vacuum modulator when blowing compressed air through it. I think I blew up the diaphragm. After doing some research it looks like a 1993-1997 Land Cruiser EGR modulator may be a replacement that works. I will report back if it does.

Thanks for reading and I hope you never have to do this.

[Ian R.]

Update. Got the EGR vacuum modulator in today. It appears exactly the same. I installed and ran the ERG Diagnostic test per the Toyota repair manual, and it performed as indicated. See below images.



Here is the part description and PN from RockAuto.

Part Number	Part Type	Price EA	Core EA	Quantity	Total
1997 TOYOTA LAND CRUISER 4.5L L6
STANDARD MOTOR PRODUCTS	VS93	EGR Vacuum Solenoid	$ 100.79	$ 0.00	1	$ 100.79