DI Pressure problems Syvecs S7+ PNP AUDI TTRS

Hello

i am working on a AUDI TTRS 8J CEPA Engine with the SYVECS S7+ PNP kit.

There are some strange problems with the Direct Injection Pressure in relation to the supply Fuel Pressure.

Sometimes the Direct Injection Pressure rises to 150 bar(max) with almost no change in supply Fuel Pressure.

Then the Direct Injection Pressure Valve duty drops to 0% but the Pressure stays 150 bar.

The Direct Injection Pressure is very sensitive to supply Fuel Pressure.

A change of 0,3 - 0,5 bar could cause that problem.

On the flip side the Direct Injection Pressure sometimes drop to 0 bar @ minor supply Fuel Pressure change 0,2 bar (2% Duty change).

The problems are not always repeatable so it is not possible to do the mapping work.

I have replaced the Upgrade DI Pump (other Brand) but the problem is still present.

Please take a look @ the attached Data Logs + Screenshots.

Have anyone experience with that kind of problem?

Thank you

These issues will happen if your lobe angles are not correct and I had the same issue using the ones from the base map. In the Direct Injection Pump Control -> Synchronous Pump Control -> Pump 1 Stroke Start Angles, try the values 130 370 610. Also make sure all the lengths are 120 and the VVT Depenendency Selection is set to "1 EXHAUST".

If that doesn't help, try moving it 5-10 degrees more in this direction (to 120 360 600) and if that doesn't help either try moving it in the other direction (to like 150 390 630 and 160 400 640). Also, base maps used to have wrong linearization of the high pressure sensor, it should be 0 bar @ 0.5V and 200 bar @ 4.5V (base maps had 250 bar @ 4.5V), but I reported that to Syvecs back in the day and they should've fixed it.

Hello Nenad,

thank you for the information and recommended actions.

I have measured the Lobe Angles @ the engine and corrected the map to suite.

Also the Crank Reference Tooth Angle was off by 6° in the Base Map on this car.

The linearization of the high pressure sensor was correct.