Förderbeginn springt herum bei VP37 im VW T4 ACV | Posts 16+

Hello Herbert,

FB-Target is constant.
The pump was tested on a special VP37 test bench. According to the workshop manager, it is working perfectly. I suspect that the problem might be a worn tensioner pulley for the main timing belt, and possibly vibrations that the N108 is trying to compensate for, which then cause the camshaft to resonate at an unfavorable frequency. In operation, the bus actually runs perfectly. It doesn't make excessive noise either.
The timing belt is due for replacement in 5,000 km anyway, so I can rule that out as the cause.

The story continues.
After picking up the vehicle, it was discovered that the pump start was much too early. The flow rate control was set to a higher output, which is incompatible with the chip. The front bumper was scratched due to the air conditioning condenser hanging down, and the screws on the engine cover were not tightened. And now, the kicker!
700 kilometers from home, the girlfriend had a breakdown. After 2 hours on the hard shoulder, the car was towed to a VW workshop. The diagnosis: the wiring was fine, but the fuel flow meter was defective. So, I called the "pump expert" and asked if there was anything to do with the sealing or cleaning of the fuel flow meter. "No, absolutely not!"
The VW mechanic who now had the car doubted that a pump overhaul would fix the problem, as it was still dripping. "No way, that can't be!" "It must be leaking!" In German: "It can't be that it's leaking, because we sealed it."
Okay... Thankfully, a replacement pump wasn't available from VW. That would have cost 2500€. The Touring Club provided a loan car and arranged for the bus to be towed home. We actually had the pump sent in for an overhaul to prevent any breakdowns, but with an old car, things can always happen. So, I bought a new fuel metering unit because I always want to be on the safe side.
When the bus finally arrived after 10 days, I started the replacement. I removed the old flow meter. In the process, I noticed that one of the 4 screws was completely loose!! The surface where the seal sits was corroded and dirty! I quickly removed the black plastic on the right side again, and...
"Believe it or not, a loose pin is actually what I found. Not even a trace of solder was detected. Furthermore, the contacts shouldn't be soldered together under tension. Even just bending the contacts cleared the error memory and caused the quantity indicator to malfunction when the ignition was turned on."
What else can you say? You go to a fuel pump specialist and pay €900 for a sealing and cleaning to avoid breakdowns, and then you get a car with scratches and a leaky pump that breaks down after just one month and 2000 kilometers. On top of all the stress and the danger on the highway, there are additional costs that could have almost reached €3,000.
Basically, I could have repaired all of this myself, done a better job, and saved a significant amount of money.
Oh yeah: I soldered the pin, put the lid on, and when I turned the key for the first time, it was working again .
Conclusion: Do everything yourself!
Now I'm arguing with the guy who wants to make corrections, but doesn't want to talk about costs .
He was lucky, though, because the costs could have turned out to be much higher for him.
Are there any words left to say?

Very annoying, but now the car is working again, well done.

For the work on the ESP, there are specialized articles here. Sometimes, I also delegate tasks to relieve myself, but I could later regret it...

For readers interested in this topic, here are some relevant links:
Ich kann den Inhalt dieser URL nicht abrufen, da ich keinen Zugriff auf das Internet habe. Bitte gib mir den Text, den du übersetzt haben möchtest.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Rainer.

Thanks for the links! And while I have you, may I ask you something?
"Is there a way to precisely reposition the fuel injection pump after it's been removed, so that it's in the exact same position as before? I've always marked the position on the pump and felt like I was getting the same performance and starting behavior as before. The mechanic told me that the bus had initially started poorly and had less power, and then he adjusted it, which resulted in negative side effects for me, such as rough running when the engine wasn't fully warm and increased smoke."
Can a pump specialist not adjust this precisely using a measuring device or VCDS?

Thank you!

Tagessuppe wrote:

Thank you for the links! Since I have you on the line, may I ask you something? Specifically, is there a way to reposition the fuel injection pump after removal to its exact original position? I've always marked the position on the pump and have always felt like I was getting the same performance and starting behavior as before. The mechanic told me that the bus had initially started poorly and had less power, and then he moved it, which resulted in negative side effects for me, such as rough running when not yet at operating temperature and increased smoke. Can a pump specialist not adjust this precisely using a measuring device or VCDS? Thank you!

Hi,

Sure, you can configure it exactly the same way as before, see https://community.dieselschrauber.org/en/viewtopic.php?t=5517.

Marking a "reference position" still makes sense, as the turnout mechanism is quite sensitive to positional changes.
You can also adjust it so that, with a warm engine and the air conditioning off, the injection amount at idle is 3-4 mg/hour.

Best regards, Rainer.

Hello,

I'm having the same problem. What was the solution?

Best regards, René.

Is the car running properly?

rene-caddy wrote:

Hello, I'm having the same problem. What was the solution? Greetings, René

.

No solution found yet. According to VCDS, the fuel injection start is fluctuating.
The engine is running normally.