Julio77270

Hello,

Is' m gonna explain you the problem I have on my SLK 32 AMG.

I hope finding some advices or solutions to my problem.

My mods are : NW intercooler, tweaked manis, 181 EC pulleys, downpipe, DCAI, Oil catch, 255 walbro kit with the OEM pressure regulator.
I have changed as parts : sparks and wires, ignition coils, IAT sensor, MAP sensor, CPS.

The car is very fun to drive until 5400 rpm (390 engine hp). After that, I lost all my power (310 engine hp). ALWAYS AT THE SAME REV.
You will attached the dyno.

Also, I have obtained the logs from my tuners and the conclusion is :
-Air pressure is correct to the red line
-Timing ignition is also correct
-Air flow (which is a calculation based on the throttle body position) looks like exact the same curve like the power. i think it is not normal and maybe it is the main problem, right?
You will also find the logs datas.

Another thing very strange is that the problem occurs at 5500rpm (the same rev like winter mode on the automatic transmission).
What is the cause of this problem?

1) Problem with the TCU?
2) No enough fuel (lean condition) / AFR problem? My tuner has injected more than 10 maps with more fuel without any positive effects...
3) Problem with the TPS? Pedal assembly?
4) Another issue?

Thanks for your help because investigations make me crazy...
Julio

Julio77270

Nobody can help me ?

Guran

Hi Julio
Have you Checked IAT and AFR value ?
I have a SL55 amg Fuel pump and no pressure regulator. That fuel pump can handle a lot. About 800 hp and more.
I know that our cars i at max load at 5400 rpm - 5800 rpm. But i dont think that is the problem.
Lets see what your IAT and AFR value is.

It could be in the restriction in the TCU and the Gearbox. You only get 60 % of the power from the engine original to the wheel.

Regards Göran

Julio77270

Thank you Guran for your answer!


My IAT are very good around ~30°C more than the ambient temperature.


I haven't yet diagnosed the AFR.
But I have a 255 walbro fuel pump kit installed on my car with the standard pressure regulator. Maybe it is the main problem ?


Do you have a standard pressure regulator or none regulator on your car?
What is the restriction in the TCU ? I need to remove the load restriction ?


Thanks,
Julio

Guran

I have a standard fuelfilter with 3,8 bar regulator and a SL55 AMG fuel pump.
If the TPS is closing is must be the TCU or ECU. Can you read the TPS in your logg. Probably you have to increase your Torque limiter.
I have removed all limits.
Your Fuelinjectors is to small ?
Lets find out the AFR value

Julio77270

I think you are right because my torque limiter in ECU has not been completely removed!
My tuner is looking for on this way.

Concerning my fuel injector, I have the OEM ones and I have planned to installed a variable fuel regulator

Julio77270

The problem on my car comes from an air mass flow issue.

How is calculated the air mass flow in our car?
I guess with IAT, MAP, throttle body sensor. Is it right?

cm60k

I think your right, MAP which calculate the air,,

prefer if you can post in C32 section, more active guys there..

ZAYED,,

Guran

You can have a leak ? Plenum and all connections.
I have had same problem when the pressure is at top.
New gasket and form a gasket 3 glue. Works for me

Julio77270

I have checked all the gasket and replaced them by new ones without any good effects.

It sound like a mass air flow issue.
How it is calculed?

By AT sensor.
1) Maybe it is bad. I have changed it twice.
2) water pump is going bad?

by Map sensor :
1) what is the best reference to have ?

By throttle body sensor or pedal assembly?

Thank you for your help
Julio