Thread: Provent 200 outcome after 150,000km

Originally Posted by gonetropo

we had a mitsi triton with the 4d56, carbon buildup was an issue. after cleaning it all out i fitted a 5k6 resistor in series with the intake air temp sensor. this caused the ecu to think the air temperature was 0 celsius and turned off the egr valve

I was a member of a 4WD club in Kalgoorlie for 6 years. We did lots of weekenders out into the bush, I was driving the work Prado V6. Most of the guys were modification fanatics and spent a lot of time and money fiddling with their trucks - mostly Land Cruisers, Patrols, Hilux. I’ve stayed in touch with some of those guys and over time they have upgraded and are now onto some pretty wicked builds with later model vehicles.

The reason I did not do the EGR delete either electronically or by a blanking plate is because some of my Kal mates have experienced quite serious problems with the motors running too hot, due to the ECU not being able to work out exactly what mixture it should be running for the conditions. Now I am no expert in this, but my bottom line is that I don’t want my ECU to be fooled into not controlling combustion optimally for the conditions.

What I learned from trained Denso technicians is that under certain conditions (temp, throttle, load) the motor is expecting to increase EGR to reduce the amount of oxygen in the burn and hence reduce the combustion temperature. I want the motor to be able to get exactly what it wants, when it wants it. I don’t want it to be tricked into running the wrong mixture especially when the engine is working hard, like towing, in hot Aussie weather. Especially on the kind of Nullarbor runs we used to do. It never felt remotely right to me, running an engine under load over 1000 km in hot conditions without the right ECU inputs.

There was certainly no way I was going to take off around Australia towing a camper trailer with a brand-new engine that was being fooled into running the wrong mixture just for the sake of a bit of soot. We did 66,000km on that trip and it went without any technical problems, which certainly wasn’t the case for a couple of the Kal guys who took off in 4WDs tuned for crazy power and torque and of course with EGR deletes. Excessive combustion temps cooks the oil and causes sludging and lubricity problems. The bottom ends of these motors do not like that at all…

Yesterday was the first time I’ve cracked anything open on that engine at 150,000km and I was delighted with how easy it was to give the intake a simple service. (It’s all back together now and running perfectly.)

Originally Posted by Flyblown

I was a member of a 4WD club in Kalgoorlie for 6 years. We did lots of weekenders out into the bush, I was driving the work Prado V6. Most of the guys were modification fanatics and spent a lot of time and money fiddling with their trucks - mostly Land Cruisers, Patrols, Hilux. I’ve stayed in touch with some of those guys and over time they have upgraded and are now onto some pretty wicked builds with later model vehicles.

The reason I did not do the EGR delete either electronically or by a blanking plate is because some of my Kal mates have experienced quite serious problems with the motors running too hot, due to the ECU not being able to work out exactly what mixture it should be running for the conditions. Now I am no expert in this, but my bottom line is that I don’t want my ECU to be fooled into not controlling combustion optimally for the conditions.

What I learned from trained Denso technicians is that under certain conditions (temp, throttle, load) the motor is expecting to increase EGR to reduce the amount of oxygen in the burn and hence reduce the combustion temperature. I want the motor to be able to get exactly what it wants, when it wants it. I don’t want it to be tricked into running the wrong mixture especially when the engine is working hard, like towing, in hot Aussie weather. Especially on the kind of Nullarbor runs we used to do. It never felt remotely right to me, running an engine under load over 1000 km in hot conditions without the right ECU inputs.

There was certainly no way I was going to take off around Australia towing a camper trailer with a brand-new engine that was being fooled into running the wrong mixture just for the sake of a bit of soot. We did 66,000km on that trip and it went without any technical problems, which certainly wasn’t the case for a couple of the Kal guys who took off in 4WDs tuned for crazy power and torque and of course with EGR deletes. Excessive combustion temps cooks the oil and causes sludging and lubricity problems. The bottom ends of these motors do not like that at all…

Yesterday was the first time I’ve cracked anything open on that engine at 150,000km and I was delighted with how easy it was to give the intake a simple service. (It’s all back together now and running perfectly.)

We have plates and egr deletes in both our hilux and cruiser and both previous hiluxes
While I'm certainly no expert at all I'm not sure your information is correct but happily to be proven wrong
The egr is only open on idle. It's never open when trying to make power.
It can't be you need make exhaust manifold pressure to create boost.

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Originally Posted by BRADS

We have plates and egr deletes in both our hilux and cruiser and both previous hiluxes
While I'm certainly no expert at all I'm not sure your information is correct but happily to be proven wrong
The egr is only open on idle. It's never open when trying to make power.
It can't be you need make exhaust manifold pressure to create boost.

I’ve got the Denso training documents somewhere. If it’s at hand I’ll post it but it’s probably archived away somewhere. You’ll be able to find it online I expect. It’s a hard read but it explains how it all works. It will be a good few years old now, at least 16 or 17 I would think.

But no, what you said is not correct. The EGR is closed on a cold start & idle and gradually opens slightly as the engine temperature warms up. The EGR operates primarily at cruising speed on low to medium engine loads. That’s the whole point - it’s there to put some exhaust gas back into the intake manifold when the engine is not working hard. It closes under hard acceleration.

Give me a few minutes because I know I’ve got a more detailed explanation somewhere from my brother-in-law in South Africa who is very much into this kind of thing.