Low Performance, High Fuel Consumption, No Ideas?

Hello everyone,

'I posted a few days ago about experiencing poor acceleration below 2000 RPM and a loss of power above 3000 RPM, along with a 20% increase in fuel consumption.'
Unfortunately, these symptoms only become noticeable at higher outside temperatures, which is why I had a lengthy appointment with the mechanic today.

First of all, a huge compliment to this workshop. I took a 1.5-hour test drive with the master mechanic, and I had the test computer on my lap (it was one of those tablet PCs with a touchscreen display).

Unfortunately, without any real results.

First, the data:

Volkswagen Golf 4, ALH engine, 101,000 km.

All filters are functioning correctly, all vacuum lines are in good condition, VTG (Variable Turbine Geometry) adjustment is working properly.

First measurement run: Air mass flow rate at 3000 RPM is approximately 800 (likely near the lower limit).
Boost pressure at 3000 RPM: ~2 bar.
Keyboard ratio of AGR and VTG valves all within the normal range.
Exhaust (37) and torque limitation (34), also located on the...
Lower limit of target values.
Idle speed control, every 0.
Intake manifold pressure and temperature are within the normal range.
No blue or black smoke (EGR seems to be working properly).
Exhaust emissions are low.
Pump setting also within the normal range (two values were recorded).
extracted and included in a diagram within the reference guide.
compared, the intersection of the values was located in the gray-marked area.
Area.


Because the LMM value was so low, it was replaced. However, this had no effect (LMM value remained at 810).
Subsequently, the technician adjusted the pump to optimize its performance.
However, the subsequent measurement run yielded the same values as the first one.

The increased fuel consumption is certainly a consequence of the poorer performance.
According to the expert, there's essentially only one possible issue left: a defective or worn-out pump.
What is the cost of a new one or a refurbished one? It's probably not worth it anymore, considering the mileage I drive; I would never recoup the investment.

What advice can you give me? Would cleaning the intake manifold make a difference? (I've never looked inside before.)

Are there perhaps other potential sources of error?

I'm always grateful for good advice.

Hello,
My fuel injection pump started leaking after 170,000 kilometers, likely due to occasional use of biodiesel. The cost estimates for repairing the leak ranged from €750 to €1500. It probably wouldn't have been worth it.
'Over Easter, I was in Hungary and discovered a diesel workshop there that reconditioned the pump for me in one day for less than 100 euros. That short trip to Hungary was definitely worth it.'
If needed, I can gladly look up the address for you.

Hi,

Henzo from dieselsend.de will replace various sealing rings and bearing bushings on the driveshaft for 100 euros!

If the installation and removal of the pump are included in this offer, then it naturally cannot be outdone .

Hello,

If your car only performs poorly in warm weather and works perfectly fine in cold weather, I would suggest having a diagnostic test performed to read the values of the intake air temperature sensor and check if they are reasonable.
They should not exceed 50°C when heating on a country road.

I would actually rule out the fuel injection pump; why should it work in cold weather but not in warm weather?

Best regards, Rainer.