Power Loss from 2250 RPM

Hello,

I'm a beginner and I'm having this problem. The guys from the 35i forum actually referred me to you, hoping that I could get help here.

I own a 35i 1Z model with 90 horsepower, manufactured in 1996, and it suddenly lost power. The engine speed was higher than usual, and from 2250 RPM onwards, it had no power at all. When I tried to accelerate at that point, the engine sputtered as if it wasn't getting any fuel.

I've been using a rapeseed oil blend in my car for about 1.5 years, with a 40% blend in the summer, without any modifications!

Okay, let's go to the workshop and first read the error codes! It showed: boost pressure control valve (twice), idle speed adjustment screw, and mass airflow sensor. The workshop checked everything and also inspected the vacuum hoses! No errors found. The mentioned parts were even replaced with new ones for testing! The fuel lines are also all okay. That leaves only the fuel pump and the engine control unit (ECU). While it's unlikely that the ECU is defective, it's cheaper than replacing the pump with installation. So, I got an ECU from an Audi A4/B5 TDI 90 PS (the only difference is the ending "G" instead of "DD" on mine) and gave it to the workshop to "test." It doesn't even work with that one.

My question is, is it worth it to get another one, and if so, which one would be the right fit? And if I do, do I need to have the Vehicle Identification Number (VIN) and immobilizer coded by a VW dealership? Or, as I suspect, is the problem actually with the fuel pump itself? As mentioned before, the fuel line is not defective.

P.S.: As soon as the error codes are cleared, they reappear in the memory, even without starting the engine.


Thank you very much for your efforts!

Hi,

Sorry, but please provide the exact error codes. What you're writing is, at least in part, nonsense. For example,

woogiedw wrote:

adjustment screw for idle speed

.

Based on the frequency of error messages, it sounds like there might be a break in the ground or power supply line. It might be worth checking the wiring diagram to see if the relevant components are connected to the same line.

PS: Regarding your question: If you want to test replacing the MSG, only the immobilizer needs to be adjusted (delete the learning values for channel zero). The VIN and other related information are not required.

Regards,
Guste.

Hello!

woogiedw wrote:

At that moment, I pressed the accelerator, and the engine sputtered as if it wasn't getting any fuel.

Have you ever considered that that might actually be true?

Diesel filter free?


Otherwise, please check the power supply (including relay 109), connectors, and wiring harness. All of your error entries might be related to these issues...

BYE
TDI mechanics.