Руководство по демоггингу двигателя Toyota 3F-E (EN)

Desmogging a 3F-E By Dan Moeller a.k.a. Spook50 Note: This was done on an FJ62’s engine. An FJ80’s 3F-E should be the same, but I can’t guarantee it. Desmogging an engine is somewhat of a controversial issue. According to federal pollution control laws, this is ILLEGAL. As a disclaimer, I must express that tampering with smog control systems (with the exception of actually maintaining the system) on pollution controlled vehicles is a violation of federal laws and punishment is subject to the laws governing your area. Also, the purpose of this writeup is to illustrate how I desmogged my vehicle, and to provide tips to anyone looking to do the same.

Any modification to your vehicle as a result of this writeup is at YOUR OWN risk and/or expense. In other words, I’m not going to buy you a new engine if you fuck it up; nor will I claim any responsibility if you get into any legal trouble as a result of desmogging.. Now that all that is out of the way, let’s get started. There are a lot of issues concerning desmogging an engine. These range from the legal ramifications, to whether or not it’s simply worth the work involved. Desmogging an engine will help free up a small amount of horsepower, though the amount of horsepower varies from engine to engine. On a 3F- E, the gain is minimal.

I could feel a slight increase in overall performance, and low end torque was slightly improved. Obviously, this in no way, shape, or form will make your engine hold its own against the likes of a 426 HEMI. The biggest benefit to desmogging the 3F-E in our Cruisers is the massive amount of real-estate you’ll free up under the hood. Now for the cons. First of all, it’s a rather involving task. I did all the extra stuff that, while not crucial to the desmogging process, cleaned up the engine compartment greatly, and put the engine that much closer to what a “factory smog-free” 3F-E might have been. It’s also somewhat costly.

There were several miscellaneous parts to buy in the process (one of which needed to be custom made.) of desmogging. A parts list follows. • Seven 1/8” vacuum plugs. • “HELP!” brand # 02254 bypass caps • Dayco Part # 22528 belt. • Toyota EGR intake manifold gasket. May need to be ordered. • Four Toyota part # 90340-14001 plugs. Some like to use ј NPT plugs, but the Toyota parts are made just for what we’re doing, so I opted for those. • High temp thread sealer • Catalytic converter straight pipes. These can be either welded on or custom made as bolt-on. It cost me $90 to get my pipes, do to having them bolt-on. Having them welded in place will most likely be much cheaper (but irreversible).

• Intake manifold EGR block-off plate. This is custom cut to match the EGR gasket. I had mine cut from 1/8” stainless steel, which cost about $65 and took a few days, so get this done early on. • Exhaust manifold EGR plug. Lowes carries both a single cast plug and a brass fitting that will fit the exhaust manifold. I opted for the brass fitting with a small

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plug to fit that, as both were NPT spec; and brass, being a softer metal, will form a positive seal against the manifold’s threads. The part #s are A-870 for the fitting and A-823 for the plug. Plumbing section of course. There are basically three major steps to desmogging a 3F-E. I’ll break this down into three sections so I can more easily explain what I did. Section 1 – Remove catalytic converters This was the first thing I did to desmog my truck. It will allow your exhaust to breathe much better, and the reduced backpressure will NOT interfere with the operation of your engine or its ECU.

I wanted something that I could reverse if need be, as I wasn’t sure if I’d end up having to replace the cats in the future. As it turns out, my ’88 FJ62 will be old enough to not require smog checks by the time I’m a civilian again and living in a smog controlled area. If you want a guaranteed seal where the cats are removed, you can simply weld new pipes in place. My flanges like to leak around the gaskets occasionally, and I’m now wishing I had gotten them welded. Having the pipes made a big difference in the amount of power my truck had on the highway, and it sounds a lot better too (with a Flowmaster 50 series muffler and 2.5” pipe from the Y-pipe back).

I highly recommend finding a small performance exhaust shop local to your area that you can go to. Larger shops like Midas or ones that do work for any fleet company will most likely not do this for you (again, federal pollution control, and they are watched for just such jobs). Be ready to pay with cash, too. This keeps it under the table and keeps both of you out of trouble in case some tree hugger gets nosey.

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Bolt-on cat replacements to free up the exhaust. If you want the most free-flow system you can get for a 3F-E, you can buy headers and larger downpipes leading to the forward cat flanges. This is not an endorsement, but Man-A-Fre sells both. Be warned: it’s costly, and the effectiveness of 3F-E headers is often debated. Section 2 – Disable & remove air injection system Here’s where it’s going to start getting tricky. I’ve included some pics to help out a bit. First, look at your air pump. You’ll notice that there are two hoses connected to it. One leading to the union between the air filter housing and the MAF, and the other leading to the VSV (part # 5 in the pic).

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Use this pic for part references Remove these hoses and leave the air pump alone for now. Cap the fitting on the air filter housing. I couldn’t find a perfect sized cap, but the “HELP!” bypass cap worked well enough. Took a little work to get it on there, but at least I know it’s a nice tight seal that won’t come loose anytime soon. Remove the silencer mounted just forward of the fender (part # 69 in the pic) and cap its hose connection on the VSV as well. At this point, you can continue on to the removal of the VSV, or simply cap the VSV’s hose connection for the time being.

I recommend doing that for now, as that’s what I ended up doing, and it gave the ECU a chance to “learn” that the air pump isn’t pulling air out of the intake anymore. The first two or three times you start and run your engine, it’ll idle high (about 1000 RPM). I drove it several times, each over 15 minute drives to allow the ECU’s programming to change. You’ll have to do this every time you disconnect your battery for extended periods of time also, as the ECU by default expects the air pump to be there. Now, before tackling all the crap mounted on the fender (yes, all of it will be gone by the time you’re done), remove the air pump and replace its belt with your Dayco belt.

This new belt will bypass both the air pump and the alternator, and it’ll be necessary to adjust the idler pulley underneath the power steering pump quite a bit, which is a pain.

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