EGR on 1HD-FTE to block or not to block?
Submitted: Tuesday, Jul 21, 2015 at 18:44
ThreadID:
119562
Views:
27178
Replies:
7
FollowUps:
23
This Thread has been Archived
1HD-FTE
Quite possibly an old topic here but I have to see if any boffins have any answers....
Thinking of blocking the EGR on my 1HD-FTE, for some obvious reasons:
However these are just assumptions for now.
1. Cleaner intake, better flow.
2. Cooler air, the HDJ-78RV does not have the luxury of an intercooler. (yet...)
3. Better response, more power, if not recycling gases then should be quicker when you need to put the foot down.
4. Improved fuel economy.
My misgivings are as follows:
1. Does this recycling of carbon in any way contribute to the longevity of the 1HD-FTE? is this the reason they are such an indestructible donk?
2. The computer turns the EGR on in periods of little demand, I'm assuming that the computer ALSO lessens the amount of diesel to compensate for a reduced oxygen flow. Does this mean with a blocked EGR the car will run lean? I know in a petrol this means hotter engine, however in Diesels I'm prone to think cooler.... In which case NO PROBLEM. Or is the fuel unchanged.
3. Blocking the vacuum pipe to stop the actuator is fine if the EGR is functioning correctly, but if stuck open should I fit a plate over the EGR pipe to make sure?
4. Extra pollution. Had to add this, even though Brownwin Bishop can take a joy ride in a helicopter that would spit out 1000 times more pollution that my troopy ever could. This one is for the greenies.
Cheers for informed answers, no guesses thanks.
Reply By: garrycol - Tuesday, Jul 21, 2015 at 19:24
Tuesday, Jul 21, 2015 at 19:24
Your points 2,3 and 4 are not relevant.
As a general statement EGRs only open on trailing throttle as that is when the emissions they are designed to reduce come into play - when powering along the EGrs are closed.
So 2 is not generally relevant as hot exhaust gases are not being fed into the engine when power is being used.
3. As mentioned - not open when you need power so you will not generate more power with blanked EGRs - however if you have faulty egrs that are stuck open the engine will run like a dog.
4. If your egrs are working fine you will not have better fuel economy as they are closed on the power cycle.
The main benefit in blanking is not sending sooty abrasive deposits into the engine causing wear and clogging the intake with can cause airfliow issues if it builds up.
If the EGRs fail and it is letting exhaust in on the power side all you concerns above come into play - so there is a reliability issue.
I have a different car but I have my engine blanked and no more soot in the intake.
Garry
AnswerID:
557251
Follow Up By: 1HD-FTE - Tuesday, Jul 21, 2015 at 19:55
Tuesday, Jul 21, 2015 at 19:55
Thanks Gary, your info has cleared this up nicely and I'll be blanking my EGR off this weekend. During which I'll scrub the gunk out of the intake also. :)
FollowupID:
843532
Follow Up By: 1HD-FTE - Tuesday, Jul 21, 2015 at 20:36
Tuesday, Jul 21, 2015 at 20:36
Hi again Gary, just flicking through the Toyota factory manual and these egr are designed to operate at all times after reaching operating temp of 70 deg c and only shut off during periods of quick acceleration. So my point 2 is quite relevant and it could be reasonable to assume the computer feeds slightly more fuel before warm up and the egr starts to function. I'm starting to think I need to ask a Japanese engineer in Toyota....
FollowupID:
843535
Follow Up By: garrycol - Tuesday, Jul 21, 2015 at 21:19
Tuesday, Jul 21, 2015 at 21:19
Then if that is the case, Toyota needs to go and learn EGRs 101.
FollowupID:
843540
Follow Up By: 1HD-FTE - Wednesday, Jul 22, 2015 at 07:48
Wednesday, Jul 22, 2015 at 07:48
Damn right Gary, you should contact Toyota engineering and explain why all of their engineers are wrong and you are right. But I think you'll find they are pretty arrogant with their opinions, Toyota generally are...
FollowupID:
843551
Follow Up By: garrycol - Wednesday, Jul 22, 2015 at 12:28
Wednesday, Jul 22, 2015 at 12:28
If the EGRs are open except for periods of fast acceleration then they are using a very early generation of egr system - maybe that is why Jap diesels are not at the forefront of diesel technology.
Maybe Toyota need to take some lessons from European diesel makers where the EGrs are only open when the NOx emmisions are being generated which is when the engine is generating little power - closed or trailing throttle.
However given what your manual says I would definitely be getting your engine blanked because the EGR design is strangling your engine even when they are fully serviceable.
On a modern diesel with a proper EGR system the engine develops full power and gives good fuel consumption and it is only when EGRs fail that engine performance and fuel consumption is impacted.
FollowupID:
843562
Follow Up By: 1HD-FTE - Wednesday, Jul 22, 2015 at 18:16
Wednesday, Jul 22, 2015 at 18:16
Roger that. It makes little sense to me to have the engine pumping in exhaust gases even though you might only be cruising down the highway on low revs. Unless I have got this wrong, but like I said the factory manual says as much.
Going to shove a resistor in the vacuum pass through solenoid, manual states 11-13 ohm, which means the damn thing will be drawing a solid amp. Going to need at least a 15W resistor! Crazy.... but this is just to see if the ECU complains, of course the easiest way is just to block the EGR vacuum pipe followed by this weekend blanking up the big sucker....
FollowupID:
843582
Follow Up By: garrycol - Wednesday, Jul 22, 2015 at 19:49
Wednesday, Jul 22, 2015 at 19:49
Irrespective of the why fores and why different manufacturers do things, they all did - it was a bad idea for all manufacturers to do this and as the user of the vehicle I consider one of the smartest things you can do is blank the egrs.
FollowupID:
843587
Follow Up By: pop2jocem - Wednesday, Jul 22, 2015 at 22:43
Wednesday, Jul 22, 2015 at 22:43
I guess whether Mr Toyota is up with the latest technology with regard to diesel engines may be a matter of conjecture.
I kinda get the idea that the use of EGR was little more than a stop gap measure until more efficient and proven methods were available.
Maybe we should keep in mind that as reliable, and for their day, as advanced as the 1HD-FTE was, we are discussing nigh on 20 year old technology.
I could be wrong but my understanding was that the various manufactures that employed an EGR system were trying to reduce NOX emissions. Those nasties that came out the tail pipe when combustion temperatures got beyond a certain level. Their answer was to throw a bit of exhaust gas on the fire, so speak, reducing the burn temps and thereby reducing NOX.
Unfortunately they also added a few particulates which can be a tad abrasive and also required the addition of particulate filters to stop them escaping into the atmosphere.
Cheers
Pop
FollowupID:
843589
Follow Up By: The Landy - Wednesday, Jul 22, 2015 at 22:53
Wednesday, Jul 22, 2015 at 22:53
Let's call it for what it is...
No engine manufacturer would incorporate this into its engine if it had a choice. It was imposed on them in the interest of emissions control!
Bad idea that we have been lumbered with.
Mind you tinkering with it potentially puts you at odds with vehicle compliance, but on balance you have to ask yourself will a few "blanked out" EGRs have that much effect vs everything else we "punch" into the atmosphere?
Given the cost of vehicles these days, I'll put self interest first in this instance and preserve the integrity of the vehicle by making this adjustment.
Cheers, Baz - The Landy
FollowupID:
843591