1.9 TDI: Running Issues After Engine Rebuild

Two months ago, I likely got a hole in the piston due to a faulty nozzle. Now, I've had the engine completely rebuilt.

Inspected and refurbished:

Turbo, ESP (Electronic Stability Program), starter motor, alternator, new piston and cylinder liner, crankshaft and connecting rod bearings, new timing belt.

The following items have been added: 205 injectors from the AFN engine. These have been refurbished and tested by Bosch. The rest, including the ECU, is stock. The start of injection has been precisely adjusted to the middle of the range using TDI timing.

Initially, the car wouldn't start at all. It almost stalled just when I was trying to engage the clutch. There was also a noticeable clicking sound. A second check of all the connecting rod bearings yielded no results.
In addition, the magnetic solenoid valve that connects to the turbocharger, air intake system, etc., and is located on the injection nozzle was replaced. The catalytic converter is also functioning correctly and has good flow.

After that, the car ran a little better, but it still wasn't quite right.

The shifting is working pretty well. However, the turbo doesn't kick in at all until around 2000 rpm. In any case, the engine speed increases very slowly.
I've attached a recent log file. (3rd gear, full throttle, 2000-4000 rpm).

The first two values represent the idle speed. I noticed that it seems to occasionally drop to 880 rpm. You can see that the turbocharger doesn't really start delivering the target values until around 3000 rpm. However, it apparently doesn't achieve much even then. I stopped the test at 3700 rpm because it had already been running for 28 seconds.
"It's also interesting to note this light clicking sound. It's not present when the engine is first started, but if you briefly increase the engine speed or drive a few meters, it appears and remains. The fuel consumption is also quite high. During the first half hour in the city, it was up to 16 liters. On the highway, it was still 8.8 liters at 120 km/h – which is still quite a lot. After 500 kilometers, the consumption in the city dropped to around 6-7 liters... which is certainly better. Does this indicate some kind of resistance that the engine is working against?"

The next thing to consider was whether the exhaust might be somehow blocked...? On the other hand, you can already feel a pulsing sensation at the tailpipe...
Or what else could it be, based on the description? I mean, we've pretty much gone through everything already.

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How many kilometers have the fuel injectors been in service?

Roadrunner505 wrote:

The following items have been checked and refurbished: Turbo, ESP (Electronic Stability Program), starter motor, alternator, new piston and cylinder liner, crankshaft and connecting rod bearings, new timing belt. The following items have been added: 205 injectors from the AFN engine. These have been refurbished and tested by Bosch. The rest, including the ECU, is stock. The start of injection has been precisely adjusted to the middle of the timing range, using TDI timing as a reference. First, the car wouldn't start at all. It almost stalled just when I was trying to engage the clutch. There was also a noticeable clicking sound.

Hi,

Based on the log and the description of the problem, I initially suspect a misadjusted engine control unit, possibly affecting valve timing or the pump, even though the settings appear to be correct.

During the same test run, log data for parameters MWB 8, 10, and the injection start control (4, if I recall correctly). This will allow you to observe the pump settings in a real-world operating scenario.

Are the diesel lines and filters definitely clear? Are there any air bubbles in the suction line?

The injectors are used, but they have been tested and checked three times. According to Bosch, they are 100% okay. I don't have any air in the system.

"When I started the engine today, it shook quite a bit. But that went away after about a minute. And there was also some light smoke that I couldn't ignore... By the way, it doesn't produce any exhaust smoke at all, neither under full load nor otherwise. Not even with the chipped ECU, which supposedly allows for 51mg of extra emissions..."

I completed the log as discussed.

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Roadrunner505 wrote:

He doesn't smoke at all. Neither under full load, nor otherwise. Not even with the chipped ECU, which releases a whopping 51 mg...?

How did it behave with that engine control unit (ECU) before the engine overhaul?

Quote:

I did the log as we discussed.

The start of the injection is unremarkable = OK.
"Was if anything was adjusted on the pump (MSW)?"

"Let's log the MWB 1 while it's idling; maybe we can get some useful data from that."

Regarding soot emissions, there was never any issue with the chipped ECU before. However, I did notice one thing. Once, I had a chip that increased the power to approximately 105 hp. At some point, the engine speed sensor only registered 90 hp. With the stock ECU, it also showed 90 hp. Then I got another chip, and with that, the torque values went back up to 105 hp. It should be noted that more power was actually expected.

Decreasing performance... - even though a series CVT (Continuously Variable Transmission) should deliver the original power output?

Okay, here's the log for Group 1 again.

P.S. I deleted the log because I attached the wrong one...

Roadrunner505 wrote:

Well, here's the log for group 1 again.

No, that's group 0, and I can't make any sense of those dimensionless numbers.

What about the tax deadlines?

Sorry, my mistake about the group.

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Roadrunner505 wrote:

Sorry, my mistake about the group.

Okay, group 1 seems to confirm my suspicion:
Either the pump is running very "lean" (resulting in a high indicated fuel quantity), or the motor's efficiency has been reduced, for example, due to misadjusted valve timing.

The machine was only lukewarm at 29°C, but even so, >8mg is quite a lot. Or did you have power-hungry appliances running (lots of electronics, air conditioning, etc.)?

Checking the valve timing is usually described in conjunction with a water pump replacement -> search function .

Hi,

Quote:

It's also interesting to note this light clicking sound.

If it sounds like I think it does, then I'd say the person who assembled the motor should fix it, end of story. That's not your problem. You ordered a functional motor, not one that makes loud clicking noises.

Best regards, Rainer.

Okay, so I invested another 50 euros to confirm that the timing and fuel pump are perfectly adjusted. The result is the same.

"The average fuel consumption is around 9 liters. The engine lacks power, and the turbocharger isn't boosting properly. Another noticeable issue is that the engine is already injecting 8-10mg of fuel per stroke when idling. When I combine this with approximately 0.2 bar too little turbocharger pressure, it results in a lot of soot."

However, there is absolutely no evidence of soot buildup, regardless of the driving conditions.

My thinking is that the exhaust system might be leaking somewhere. Is there anyone who can support my theory before I spend a lot of money having the entire system inspected or replaced?

P.S. There used to be sound files here, but I've updated them and you can find them further down in the post.

The EDC believes that it wastes 10 mg of fuel at idle.
The 1Z adds up to 35mg.

Okay, mine is showing a reading of 4 mg, which is less than half.

If your engine is now completely in good condition, it's simply being de-tuned prematurely because the EDC *thinks* it needs to do that.

Either the HDK ring is deformed within the ESP, or the quantity setting mechanism is incorrectly positioned on the ESP.

So, if I understand you correctly, you're saying the problem lies with the fuel injection pump, specifically that it's not injecting as much fuel as it's measuring, and that this is causing a lack of fuel? That would then explain why there's no soot...

Can this fuel injection system, etc., be checked? And where would be the best place to have it done? Could that clicking sound also be coming from the fuel injection pump? I mean, all the mechanical parts like bearings have already been checked for play...

Mir fällt im 1. Log der Ladedruck auch ziemlich negativ auf. Der erreicht erst bei ~2.800/min seinen Sollwert. Very late.
Has the turbocharger boost pressure control system been checked? Is the hose connected to the control valve installed incorrectly?

Roger wrote:

Was the turbocharger boost control system checked? Was the hose connected to the control valve installed incorrectly?

"Good idea. I just took a quick look. These are the three pressure hoses that connect to this control valve. The one on the upper part of the control valve connects to the black pipe for the intake air. That's obvious. It's possible that the blue and red ones are switched, as they both go to the turbocharger or to that other pressure sensor... Unfortunately, I can't see where each one is connected (they disappear down there - but they were both connected!). If I switch them, there's no noticeable difference (? which is also strange?). But I'll double-check it 100% tomorrow."

It's also interesting to note that I have very little torque even at lower RPMs, up to 1500 rpm, so much so that the car almost stalls when shifting uphill. This can hardly be related to the turbo...

The fuel consumption is currently enormous, especially at low speeds and when the car is stationary. The display shows over 16 liters.

If I revisit the idea that more fuel is being displayed than is actually being consumed, then wouldn't I ultimately notice it by the fact that, even though the average consumption since filling up is 9 liters, I can travel significantly further?