about toyota diesel tuning

Hello,

Currently I am facing a scenario that when I did the EGR off for the toyota Hilux, the car will not hit it's maximum engine load when it is in 3rd gear.

which it will only reaches 55% of engine load and output only 75mm3 fuel injection. I wonder if it is the desired airmass map that forces the car not to hit it maximum engine load?

and it also happens to me when I change the injectors, the high end rpm which is after 2500rpm the torque drops dramatically, and the high end is like drops to zero torque or horsepower, I wonder how I can bring back the high end rpm power from the engine?

the boost hit's it target, the rail pressure hits it target, but just the engine load isnt going above 50%. I had tried a couples of ways to tune but same result.

Sorry for my English, and looking forward to hear from you guys.

Hi,

Can you tell me the engine model and model year?

Can you tell me if you are Manual or Auto Transmission?

Are you remapping or using a chip?

Did you remove all the EGR components or did you only block off the ports with blank plates?

This will help to give a better understanding and solution.

Alex R

Hi,

I have 2 models that I have problem with, it is a 2012 toyota coaster 4.0L diesel turbo N04C, and the other one Toyota Hiace, from 2007-2015

engine is 1KD-FTV.

Toyota Coaster I have egr problem, I had the EGR off, but not the map, just DTC, and I did blanks the egr.

then when I do 3rd gear going up hill the engine load will drops to 55% when I hit around 39KM, intake temperature is around 35degrees Celsius.

injection volume is around 75mm3, boost is at 0.5bar, at 2500rpm, no matter how hard i throttle, it just remain the same, but when I shift to 4th gear, the car can hit around 98% engine load. and can accelerate a bit on the hill.

2nd question is,

when I change the injectors of toyota hiace (1KD-FTV) engine, without remap, the engine will starts to drop at 2500rpm, and when I hit 3000rpm it is near accelerate, and the engine loads also like capped at 50%ish , I wonder what restrict the car from doing 90%+ engine load, since all data seems to be fine form me, rail pressure is at target, boost is at target, I wonder if it is the air flow that makes the car not able to keep the horsepower to high end rpm.

many thanks for your time! looking forward to hear from you.

if you need any datalog or dyno graph please let me know many thanks!

Hi,

It sounds like your Coaster is still in Limp Mode. As the EGR is blocked off then it will have no effect on the intake. So if it is still installed the ECU can make changes but they would have no action but the ECU would still be happy. If the whole EGR system has been removed and the ECU not receiving the correct feedback then it will go into limp mode as it will not allow full throttle it the EGR is open.

It is best that when doing the EGR, only blank of the ports but leave all the hardware in-place. Ensure there are no exhaust leaks/vacuum and boost pressure sensors are hooked up to sources. Clean the MAF sensor as this is used to determine how the EGR operates. The MAF sensor is used to determine how much the valve would open If a difference is detected then again the engine e will go to limp mode until the fault self clears/ or you do a reset.

I see that the boost is a bit low. As this engine is fitted with a VNT it should be a bit higher. This is possibly stuck, if you can simulate the VNT Stepper and ensure that it is responding. it seems that you are not getting the correct exhaust flow to drive the turbo until the fueling is increased, as if you had a much larger turbo installed. The VNT should give consistent boost at all ranges.

Check you have no DTC's and then go from there.

For the 1KD-FTV, with larger injectors then the ECU must be told that the size has changed, again it seems that the engine is going to limp mode.

The ECU will be seeing a larger volume of fuel being consumed at the injectors but not the air flow to match, this will result in loss of power. This can only be corrected by remapping the ecu to compensate for the larger injector that can then be used to match the correct injection volume and also control the VNT position on the turbo to ensure the volumes match for fuel/air.

I hope that this helps to guide you in the right direction. This is what I have found from my experience with Diesel Engines. Normally its a sensor that needs cleaned or a source line is bad.