Need help to de-smog a 76 FJ40 (1 Viewer)

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Jun 5, 2011
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Navarre Florida
Anyone with experience on this?

Can anyone help me out with stock 2F that has been partially desmogged.....what can be unplugged and capped with a stock carb? the air rail has been removed and the ports plugged, the air pump and the hoses attached to it have been removed, but everything else is still there. I know that things aren't working correctly right now.....system not complete.
 
Here's some advice from a learned cruiser lover. Also note that Jim C sells some of the needed rubber caps/plugs, etc.

How to DE-SMOG a 78 Toyota Land Cruiser with a 2F Engine

NOTE: Let me warn you that in most parts of the USA removing your factory installed pollution equipment is illegal. It is your responsibility to know the laws covering your area and the usage of your de-smogged Cruiser. Secondly it is a great value to have the TOYOTA emissions manual handy and memorized. A complete understanding of how each system works is invaluable. With all that said, this is the synopsis of Jo's de-smogging broken down by system.

PVC - Keep, ensure it’s working & plumbed correctly. (The Toyota PCV valve is far superior to any aftermarket part).

EVAP - Remove VCV & BVSV & canister outer vent control valve. Hook the purge port to a ported vacuum source, preferably the higher up one. (You'll want the lower (a.k.a. stronger) port for the vac advance). The big canister hose is run up the firewall, then looped around 180° so the end points straight down. Now it is a deep-water vent for the fuel tank.

TP - Remove

Spark Control - Bypass VSV & BVSV, on distributor - plug rear on dist (retard) & connect front (advance) direct to "advancer port" on carb. (This should result in ported vacuum giving you 0 advance at idle, moderate at part throttle and weak at full throttle). For a finished look, run a hose from the retard side of distributor up to an open fitting on the air cleaner housing.

EGR - Remove, cap exhaust manifold & carb. To cap the exhaust manifold, remove the pipe, cut it so there's 2" left, then smash flat in a vise, and weld shut. Alternative to welding, put some Hi-Temp Red RTV in the end of cut off pipe, then smash flat, then fold over and smash flat again (like the end of a toothpaste tube). Try to use the old pipe stub because it is hard to get a piece of flat plate to seal up on the EGR flange, it needs the nipple that goes into the port to protect the little gasket from getting blown out immediately.

Air Injection Rail - Remove, cap air cleaner (at least the one that is downstream of the air filter), plug exhaust manifold using 1/4" pipe plugs in the head. Screw them all the way down in. They'll hit the bottom and stop just below the surface.

Hot Air Intake - Keep, ensure it’s working & plumbed correctly. Hook to hot air thermo valve located in body of air cleaner.

Heat Riser Valve - Ensure it’s working correctly

Choke Breaker - Connect to manifold vacuum.

Timing - Start at stock (7° BTDC), check to see what full advance (mechanical + vacuum + initial setting) is. It should be set up for maximum timing of 38°. A little less is ok, but don't go over 38°with all the timing in. You should be able to set it at 9-10° using 87 octane.

Note: After all the above has been done, the VSV & computer can be removed. In addition, if equipped with a WOT switch above the gas pedal and/or vacuum surge can on the drivers fenderwell, they can also be removed.

Special thanks to Jim C for all the advice!
 
I'm in the process right now of helping a friend get his FJ40 running right. It was desmogged with out his knowledge by a local shop :roll eyes: a few years ago and we are just now getting it sorted out. He just rebuild the carb with pinhead's instructions on you tube. good stuff.

Your truck probably runs the way it does more due to the fact that it needs a carb rebuild and a tune up vs being desmogged. Sure, it might have a vacuum leak that is causing it to run rough but if not, it's probably just the basics.

have you checked for a vacuum leak? what sort of vacuum is it pulling at idle and how steady is the needle? a cheap vacuum gauge from sears is your best diagnostic tool for these old trucks. it can really tell you a lot!

The intake exhaust manifold is notorious for leaking! Check for a leak with carb cleaner or with an unlit propane torch or straight oxygen. Be careful!

A hand held tach can be great for this and a slight rise in RPM might be all that you get from a small leak. Lots of small leaks can add up...
 
Would the process description in the second post be similar for a 4/75 40? The previous owner performed the desmog so I would like to double check there work. Also, I am in the process of installing a new wiring harness and would like to avoid wiring in the computer and vacuum switching valve. Attached is a photo of the guts if someone has time to double check.

ForumRunner_20120506_160840.jpg

Thanks
Dane

ForumRunner_20120506_160840.jpg
 
I'm also interested if these instructions apply to a 4/75. Mine has a previous owner desmog as well. It's "backfiring" through the exhaust while engine breaking. Need to check the timing and air/fuel, but an incorrect desmog with a vacum could be causing it. I want to make sure it was done right.
 

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