EGR bypass on 1HDFT (1 Viewer)

[Zim80s]

Good day guys....
Looking for some advice please.....How can i best do away with my EGR system. I have cleaned the system and tested all the vacuum lines and solenoids and everything seems to be okay...as soon as i press the accelerator a bit hard the damn glow light comes on and when i checked the code its 71 EGR system error so i was just thinking of doing away with it completely.....Also when the glow light comes on the truck smokes a bit more and performance is very sluggish....any advice at all will be welcome.

 

[gilmorneau]

You might have better luck in the "diesel" section of 'Mud if the moderators will move this, but I'll take a stab at it.

How can i best do away with my EGR system.

There are a few ways to do this. You can just re-arrange the vacuum hoses on the valves as in the photo below. Doing so will keep the EGR valves from opening when the VSV "tells" them to (because they won't be getting vacuum). The emissions computer will still "think" everything's OK, but nothing will actually be happening. That's assuming, of course, that your EGR valve(s) aren't stuck open (which may be the cause of your problem).

If your EGR valve(s) are stuck open, you can remove them and install plates such as in the photo below. You can fabricate them from aluminum or buy some from various online vendors. If you do this, you'll need to add a ground strap (as in the photo) for the pre-heater to operate normally.

Either of the above options shouldn't confuse the emissions computer, since all the wiring and VSV's will still be in place. If you want to remove the whole system, that's a little more involved. It's kind of like a cancer that's entangled with other, more useful cells.

The Toyota FSM for the emissions system of the 1HD-FT is in the "resources" section of 'Mud. You'll find it here:

FSM - Repair Manual for Emission Control 1HD-FT

This manual provides service information for the emissions control systems found on some 1995-1997 HDJ80 that are equipped with 1HD-FT 24-valve diesel motors. Supplement to 1HD-FT Engine Repair Manual RM437E. Included: Positive Crankcase...

forum.ih8mud.com

That's probably the most complete explanation of how it all works.

 

[Zim80s]

You might have better luck in the "diesel" section of 'Mud if the moderators will move this, but I'll take a stab at it.


There are a few ways to do this. You can just re-arrange the vacuum hoses on the valves as in the photo below. Doing so will keep the EGR valves from opening when the VSV "tells" them to (because they won't be getting vacuum). The emissions computer will still "think" everything's OK, but nothing will actually be happening. That's assuming, of course, that your EGR valve(s) aren't stuck open (which may be the cause of your problem).
View attachment 3505719


If your EGR valve(s) are stuck open, you can remove them and install plates such as in the photo below. You can fabricate them from aluminum or buy some from various online vendors. If you do this, you'll need to add a ground strap (as in the photo) for the pre-heater to operate normally.
View attachment 3505721

Either of the above options shouldn't confuse the emissions computer, since all the wiring and VSV's will still be in place. If you want to remove the whole system, that's a little more involved. It's kind of like a cancer that's entangled with other, more useful cells.

The Toyota FSM for the emissions system of the 1HD-FT is in the "resources" section of 'Mud. You'll find it here:

FSM - Repair Manual for Emission Control 1HD-FT

This manual provides service information for the emissions control systems found on some 1995-1997 HDJ80 that are equipped with 1HD-FT 24-valve diesel motors. Supplement to 1HD-FT Engine Repair Manual RM437E. Included: Positive Crankcase...

forum.ih8mud.com

That's probably the most complete explanation of how it all works.

Most appreciated thank you...this method looks simple enough to remove. Thank you. I will need to check online how to check if they are stuck open.