first tune - need help

I am working on my first tune. It is my car - A Toyota Glanza EP91 4efte with a TD04 Turbo and ID725 Injectors. I have a Link G4+ Monsoon ECU. Running on pump fuel.

The fuel table is really flat and I'm really confused. It is also going to higher boost than expected. I have 2 boost tables (one should be 10PSI and the other 20PSI) however, I'm not sure about this as they had been done by a tuner and I still don't know how boost tables work (haven't got to that part of the Link course yet).

I also inputted the info of the ID725 injectors but I was having a problem with the Fuel Table as at idle it was expecting numbers higher than 80%. So I put in the previous injector info I had which had also been inputted by the tuner who had initially tuned my car. I'm trying to work on it myself as the car didn't feel was working as it should.

I am road tuning so I bought the Tuner Nerd Knock Monitor Pro. I tried to set it up but I'm unsure about the configuration. I am getting a lot of knock at around 1500RPM. As I increase speed I don't get knock on 10PSI and car seems to be working ok. On 20PSI I get knock when the car is close to exceeding the wanted boost. As I said I'm still unsure about the settings in the programme.

I entered the Ignition Table for Turbocharged engines from the Practical Tuning course. I still haven't worked much on it though. I saved a pcl file. Can anyone pls help me out. So confused!

Hello please post your map here

Regards Ross

Here you go. Thanks

Hello i have made some mods for you to look over and use the compare file option to overlay and see the changes I am suggesting

unfortunately to use my map as a tune to just load in will not work as the fuel table will need totally redoing in your map i would also be downloading the latest G4+ software and then upgrading the firmware to the latest from this software once opened.

Regards Ross

Hi Ross, so I inputted all the settings you changed and started the tuning over. I started at 64% in the Fuel table at idle but it was getting leaner and leaner the higher the ECT was going, so I had to keep increasing until I got to over 80% at idle. So I stopped and decided to message you because this is too confusing!

I also noticed that the injector size you inputted is 750cc but in the info I had fund about the ID725 it was 715cc. Is there any particular reason for choosing 750cc please?

Sorry I read your post incorrectly input the correct injector size I would recheck base fuel pressure if it is return style adjust it to read 350kpa and change setting if base fuel pressure to the same if it return less system set to 450kpa and change base fuel pressure to tell ecu it is 450kpa this is approximate base line adjustment but should help. To me it sounds like the base fuel pressure is actually lower than you think. ( I hope this is the case because then it makes sense to me )

Sorry I read your post incorrectly input the correct injector size I would recheck base fuel pressure if it is return style adjust it to read 350kpa and change setting if base fuel pressure to the same if it return less system set to 450kpa and change base fuel pressure to tell ecu it is 450kpa this is approximate base line adjustment but should help. To me it sounds like the base fuel pressure is actually lower than you think. ( I hope this is the case because then it makes sense to me )

I tried to change the base fuel pressure as suggested but car didn't want to start. The car actually works better when I lower the Base Fuel Pressure number in the Fuel Main settings or if I decrease the Injector Flow @ Rated Pressure to 500cc/min as the previous tuner had set it. The fuel regulator is showing that the base fuel pressure is 5kg/cm2 but it is not connected to the ECU so I can only check the gauge in the engine bay.

Things aren't adding up and I'm getting more confused by the second. When I input the correct settings the car doesn't work well (at times it didn't even start), but when I change the above mentioned numbers it works well. With Injector Flow Rate of 500cc/min the % at idle in the Fuel Table went down to 62% and the Base Fuel Pressure in the ECU is set to 300kPa. As I said both these numbers don't match what they really should be.

Is it possible that the injector flow rate was set to 500cc/min because the injection mode is single point group? I have 1 injector per cylinder so I cannot understand why this setting was chosen when the car was previously "wired" and tuned. Can I change the injection mode to multi point group, and if so, should I set injection rate to 1/2 or 1 engine cycle pls?

You should be able to roughly calculate the fuel map change you need to make in terms of a VE number to match the real injector flow rating and base fuel pressure. My apologies if I tell you something you already know but it is easier this way.

Are you confirming the base fuel pressure with ignition on but the engine not running so there is no manifold vacuum to effect the pressure?

Assuming injector latency/dead time figures are correct.

If you set the injector volume to what it should be and the fuel pressure differential to what it actually is, you change the VE number as follows. Anyone playing at home please confirm my maths.

New VE = ("working map" VE) × square root ("working map" fuel pressure ÷ real fuel pressure) × ( "working map" injector volume ÷ injector volume)

You will probably have to massage it a bit to get it nice everywhere.

the injection should be set to multipoint injection for sure as this will throw the math totally out the window and in multi point you do not get the option to change the rate to 1 or 1/2 that totaly disapears as it is not needed

Regards Ross

I continued working on the car, changed injection mode to Multi Point Group and the best combination of numbers I found is 500cc/min for injector flow rate and 300kPa of fuel pressure. The numbers on the VE table are varying from about 60.2% to 55.2%. Still not a very wide range but there was a slight improvement from my 1st attempt.

On ignition (engine not running) I set the fuel pressure on the regulator to 350kPa and when I start the car if goes a bit below 300kPa. However, after I drive the car and go back to idle (with normal operating temperature) the fuel regulator gauge goes down to about 250kPa. Is this normal or do you think the fuel pressure is unstable?

You need to compare the vacuum the engine is generating at idle to the drop in pressure on you gauge. If there is more throttle/air bypass at start and then the engine pulls more vacuum at idle warm it may do that. There may be a change in you fuel pressure regulator behaviour as the engine and fuel warms up too which is a problem.

The drop in pressure on the gauge matches the vacuum at idle when I start the engine. However, after I've driven it for some time and then idle again, the pressure goes a bit lower. I'm not sure how I can check whether this is ok or if there's a problem.

please double check the fuel gauge is correct with another gauge conected at the same time it is common for gauges to be faulty i do see this on many many cars.

please double check the fuel gauge is correct with another gauge conected at the same time it is common for gauges to be faulty i do see this on many many cars.