Error found | Posts 32+

After many weeks, the engine is finally running properly!
The main cause was the injectors. "The 'old' injector control units were probably refurbished at some point, and the printed injector values inside the control unit don't seem right to me, because after a refurbishment, they should have different values. (The injector control units have been painted with screw paint, which they didn't originally have)."

After a lot of searching and testing, and learning a lot along the way, it's now running and responding to the throttle.

Thank you to everyone who participated in troubleshooting the issue!

Thank you for the interesting feedback.
That means that incorrect injector values (or failure to adjust them after an overhaul) can lead to such severe malfunctions.

I didn't expect that. I have to admit that I don't know the exact function of the injector values. I thought they would be used to adjust minor variations in pressure/flow. But I wouldn't have expected such a massive impact unless completely incorrect injectors were installed. Does anyone know more about this?

"With the older VEP engines, some of us installed larger nozzles (I believe there were some with diameters of 0.186, 0.205, and 0.216 mm). Is there a similar option with the injectors? I wonder if it's possible that these were originally injectors with completely different pressure/flow rates (and therefore different printed values) that were then modified during a rebuild to achieve a new pressure/flow rate, so that the printed values no longer match the actual performance." Is something like that technically possible?

Does anyone else have explanations for this blatant problem with incorrect injector values?

I just checked the part numbers of the injectors again, and I noticed something that struck me as odd because they had different indexes.

The injectors I have installed now (03L 130 277 S) have the exact same part number as the ones that are supposed to be in the Caddy, according to the vehicle identification number. The injectors that I removed have the part number 03L 130 277 B.

What is the significance of the index in CR injectors? Is it just a variation, or is it actually a completely different piece?

What made me suspicious was that all the cylinders were running poorly, and not as I would have expected if one or two injectors were faulty, which would have resulted in a misfire.

The Caddy came from a workshop, and unfortunately, I don't know much about its history. However, the person I bought the Caddy from told me that there was a dispute between the customer and the workshop (he didn't know much more himself), but either the people who worked on it lost the new calibration data, or they simply installed the wrong injectors...

Okay, I'm going to assume that the injectors are working correctly, but they might not be suitable for this engine, or they might have incorrect/unknown calibration values.

I once programmed injectors for someone after they had been replaced. They were 1.9 TDI injectors from a Passat 3BG. The engine was running rough and not cleanly until the values were entered into the engine control unit (ECU), after which it ran smoothly.

"If you have any further questions, feel free to provide more information. I'm also curious to understand why the engine exhibited this behavior."

fehresk94 wrote:

The injectors that I have installed now (03L 130 277 S) have the exact same part number that is also listed for the Caddy according to the vehicle identification number. The injectors that I removed have the part number 03L 130 277 B.

B was replaced by S. Both are suitable for CAYC (105 hp) and CAYD (102 hp) engines.

VAG part number.