Cold Start Problems & Power Steering Issues

Hey everyone!

First, let's briefly look at the data:
Mileage: 256,000 km
Type: 08-94 1Z 90PS TDI
Replacement parts: Mass Air Flow sensor (MAF), water temperature sensor, Electronic Stability Drive (ESD).
Completed: Oil change, coolant change, new tires (front), AGR valve closed.
ESP newly installed with VAGCOM - no further error messages.

It seems like my power steering pump is starting to fail. Well, when the car is cold, everything is normal, but after driving 50 km, the steering becomes heavy, and you can hear the power steering pump straining when turning, but you don't feel any jerking in the steering wheel... it's strange.
AND. Recently, when starting the car in the morning, it doesn't start immediately. It takes 2-3 attempts, and sometimes it briefly misfires on one cylinder.
Normally, the engine would rev up to 1000-1100 RPM and then immediately drop to 930 RPM. Perhaps the glow plugs are faulty? At an outside temperature of 6 degrees Celsius, it needs a preheating time of 2-3 seconds, whereas at 10-15 degrees Celsius, it only needs 1 second.
Does it help to disassemble the pens and test their heating function using the battery?

Best regards.

Eric Luja.

Hello Eric.

Your questions are 'absolutely classic,' and the search function will provide you with plenty of reading material, so get searching!

What does the servo pump sound like?
Have you checked the power steering fluid level?


AND. Recently, when starting the car in the morning, it doesn't start immediately. It takes 2-3 attempts, and sometimes it briefly misfires on one cylinder.
Normally, the engine would rev up to 1000-1100 RPM and then immediately drop to 930 RPM. Perhaps the glow plugs are faulty? At an outside temperature of 6 degrees Celsius, it needs a preheating time of 2-3 seconds, whereas at 10-15 degrees Celsius, it only needs 1 second.
Eric Luja

The TDI glow plugs don't activate at temperatures above +5°C; they only activate after the engine has started.

It doesn't just sound like glow plugs; it also sounds like a problem with the static injection timing. Even at +6°C, a TDI engine should start perfectly well without any preheating.

What/which settings did you adjust on the ESP using VAG-COM?

You can also check the spark plugs for functionality without removing them, so let's get to work...

Best regards, Georg.

Hello Georg!

So...
In my opinion, my TDI engine seems to be misfiring during cold starts in low temperatures.
So, this orange warning light on the dashboard illuminates for about 2-3 seconds.
There is no smoke cloud during cold or warm starts.
The ESP (Electronic Stability Program) is adjusted using VAGCOM software and a graphical interface. With the engine running, the pump is adjusted so that the line on the display is exactly in the middle, on the blue line.
Then, I reattached the pump securely and checked again to make sure nothing had been misaligned.
How do you check the glow plugs without disassembling anything?

Best regards,

Eric.

Hello Eric,

That there is no smoke visible is a very good sign!
That means the fuel injection timing is probably correct, and you're likely just having a 'small problem' with the glow plugs. You definitely need to check those.

Even if the glow plug system is functioning correctly, cold starting problems can occur if the temperature sensor is defective. This sensor is located on the upper radiator hose on the right side. If I'm not mistaken (professionals will correct me), it's a combination sensor with 4 wires. Two are for the temperature gauge in the instrument cluster (speedometer), and the other two are for the glow plug system.
For testing purposes, you can simply unplug the connector. Nothing significant will happen in the short term. The only things that will happen are that you won't be able to read the operating temperature, and your glow plug system will always activate, regardless of how cold or warm your engine is.

There are several ways to check the glow plugs, depending on what is available (light bulb, voltmeter, ammeter, and multimeter). This description would take too long to provide here.
Here are a couple of links that might be helpful.

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Good luck.

Georg.

Hello Georg!

Thanks for your tips! I'm going to try them out tonight.

Sure, here's the translation:

'Yes, the temperature sensor is only 1 month old, so it's brand new.'
There's no smoke during a cold start... only when you briefly rev the engine while it's still warming up does it smoke blue. I suspect the valve seals are hardened.
Oil consumption is also very low, and it hardly produces any smoke when warm, and if it does, it's usually black smoke (soot).


Regards,
Eric.

I'm back!
I took each glow plug out one by one and tested them... and wouldn't you know it... NONE of them work! I couldn't believe they were all defective, so I tested the glow plugs in the coolant heater on the cylinder head, and the water immediately started to boil. So, my testing method was correct. I simply connected the positive and negative terminals of the battery to them... and nothing... they're dead.

So, if they're all dead, you have to get new ones; there's nothing you can do about it!

Also, also check if there's voltage at the glow plugs during the preheating process. And after preheating, there shouldn't be any voltage there.
Once the engine is warm, meaning after the afterglow phase, there should be no voltage present.
It's not like your glow plug system 'deliberately' blew all the fuses...

Best regards, Georg.

Okay , so the 109 relay is working, you can hear it click in the morning. So... let's tinker around .