AJM Engine Performance & Consumption Issues

Hi,

a somewhat more complex problem...

Passat AJM '99, 136,000 km, recently purchased, still under warranty with the dealer due to "bubbling noise in the dashboard," head gasket recently replaced.
The car feels sluggish and lacks power on the highway (especially above approximately 130 km/h), struggles to accelerate, and barely reaches its top speed, or only does so with great difficulty.
Fuel consumption on the highway at a constant speed of 140 km/h is 7.5 liters, while it's significantly lower on country roads and in the city.

"Measurement data blocks were read out using VAG 1551 at VW, and no defects were found. However, we believe that the injection timing is at the extreme limit of the tolerance range, according to the target value table available in this forum."

Unfortunately, VW did not perform any measurements under full load, nor did they conduct any tests on the highway. Now the question arises: Can the increased fuel consumption be compensated for, or could it also be due to a misaligned timing belt/camshaft during the head gasket replacement?

They really don't know what else to do; they've even acquired their own VAG-Com to read the data, but version 302 doesn't support the modules for injection timing, etc.!

Has anyone had similar experiences or solutions to this problem that they can share with us?
(Unfortunately, the search has already been extensively and unsuccessfully tried.)

Quote:

Now the question is whether the increased consumption can be compensated for, or whether it could also be due to a misaligned timing belt/camshaft during the head gasket replacement!?

That is possible. Therefore, you should also start troubleshooting there.
Since I myself drive a 3B5 with an AJM engine, I can tell you that it normally revs up very nicely without feeling strained, provided everything is in order. It should reach 180 km/h relatively quickly without feeling labored. My maximum speed, with a good run-up and tailwind, is 205 km/h according to the speedometer, but I rarely exceed 180 km/h for reasons of durability .
My current fuel consumption, while driving at approximately 140 km/h with winter tires, is around 6.5 liters.

Quote:

We have already acquired our own VAG-Com to read out data, but it is version 302

.
Well, none of the VAG-COM distributors sell that kind of software anymore... Maybe you should consider getting a current version instead of outdated, cracked software.

Best regards, Rainer.