Usage Display PD

The potential sources of error in the consumption measurement in VEP diesel engines have been discussed in detail here. The result was that hardware that tends to be locked down should lead to lower power consumption in the MFA than in real-world usage.

On my Golf IV AJM, I'm observing the opposite. The MFA, which in its early years showed about 0.4l/100km too little, now shows about 0.5l/100km too much. Nothing was ever adjusted, and the KI was replaced at some point. This resulted in a small jump (to a "calibrated MFA"), but the "wandering" continued. I've been driving more aggressively for about 5Tkm. What could be worn out in the PD element? Should I expect the elements to reach their limits?

The car has 160,000 km, the actual fuel consumption remains the same, and the performance is okay.

Amen

Hi,

Wear and tear = does not always apply, it depends on what exactly is wearing out.
Holes in the nozzles clog or the pump plunger wears out = less fuel enters, the gauge shows too much.
Opening pressure is too low due to a weak spring = real fuel consumption is higher, the display shows too little.

So, it's not as simple as that. I would only replace the PD elements if the idle current control shows larger differences and these differences are also apparent when swapping the elements. Unlike the VP engine, replacing the nozzles/components here is a significant cost factor.

Best regards, Rainer