Repairing Partial Collision - AFN

In the following, I would like to address the troubleshooting of the partial truck with the help of the expertise of this forum. The manual provides some information on this, but I would like to gather, step by step, how the specialists would actually proceed. Maybe this will help others with similar problems.

Vehicle: Seat Ibiza 6k, 6/98 with AFN engine, 316,000 km mileage

Two weeks ago, the engine suddenly stalled during weekend drives to work on the highway! The engine had been experiencing intermittent hard stalls, losing power completely for 2-3 seconds. Additionally, there were occasional jerks in the lower RPM range. The vehicle was running perfectly before!

Error log indicated:

Error 550 Rule Difference and Error 765 Rule Shifter Path

Actions: Relay 109 replaced.
Powerbox removed and pump connector treated with contact spray
Diesel additive/cleaner added to fuel


Now, there's only a slight shudder noticeable in the lower RPM range, and it's intermittent! This can also be easily triggered, especially when shifting into 2nd gear and applying little to no throttle. It actually always works!

I'm ruling out the possibility of a needle valve issue, as it was only replaced recently (around 16,000 km)! But I'll check it again!

Using the VAG COM, I have found that in the '22 Ignition Angle' measurement block, field 2 shows 3.1° and field 3 shows 6.9°. I seem to remember that these were usually around 3.1°?

MWB 1 will be inspected today!

I'll probably have to tackle the cleaning of the measuring system, or does anyone have any other suggestions for now?

I also wanted to test the removal of the speed sensor to rule out the NHG (presumably a component or system).

Boro wrote:

Actions, Relay 109 replaced Powerbox removed and pump connector treated with contact spray Diesel additive/cleaner added to fuel I'll probably have to tackle cleaning the bulk separator myself, or does anyone have any other suggestions for now?

Yes: thoroughly verschandeln the pump connectors with brake cleaner and then protect them from corrosion with acid-free oil.

Reason: Many contact sprays are aggressive. While they do remove corrosion, they quickly form new corrosion through their residues -> the metal "becomes addicted", and you have to reapply them every few weeks until the connectors eventually break down.

Just measured again

Measurement Block 1: Field 2 Injection Volume fluctuates between 5.8 - 6 mg, Idle completely still.
Field 3 Rule Override Current 1.680 - 1.700 Volt in target range

Measurement Block 4: Field 2, 3.2° ahead of OT
Field 3, 4.4° off OT

The target value is specified as 2-4°! Then field 3 would be outside the tolerance.
liegen? Where is the cause here???