AFN ESP at the end of the adjustment range

Hello,

I installed a used AFN engine in my T3 van, and it has been running perfectly for many years. There's just one tiny problem:

The start of injection is electronically measured at the edge of the target range. I would need to tilt the pump further towards the engine. However, this is not possible because the elongated holes are at the end. If I tilt the pump further in the other direction, the engine will no longer start. I also had two instances of a clogged diesel filter, which resulted in the injection control system no longer functioning correctly (error message). From this, I conclude that the ESP (Electronic Stability Program) is not actually capable of significantly advancing the injection timing, meaning I would have to adjust it beyond its normal range.

'I replaced the timing belt 5,000 km ago and meticulously checked the basic timing using a dowel and ruler at that time, and it was okay. Unfortunately, I couldn't check the injection timing back then, but as far as I remember, it was always somewhere on the edge of the acceptable range.' Apparently, the ESP (Electronic Stability Program) was already operating at the edge of its adjustment range; therefore, the previous owner seems to have experienced this problem as well.

When performing a T3 procedure, a new OT (Operating Theater) marking needs to be applied. I had a professional do that, and they've done it many times before.

Following advice from the IG16 forum, I also checked the 'killer screw.' However, it was very tight, and I had to put my full weight on the 1-meter extension to loosen it. In my opinion, the stump also looks perfectly fine; there's nothing haphazardly attached or out of place.

[Please upload your own images, as they may be removed eventually!]

I haven't removed the wheel from the ESP yet, but I did look under the nut. The wedge looks fine. I couldn't detect any signs that it had been sheared.

What else should I do? Actually, everything seems to be working, but maybe there's still something wrong, or should I just ignore it and turn the ESP wheel one tooth further?

Hello.
Wolfgang.

Hello.

My concern arises with the homemade timing mark. I would remove the injector from cylinder 1 and determine the top dead center (TDC) by observing the piston of cylinder 1. You can either make a micrometer holder from an old injector, or insert something that indicates movement and won't break off or fall in (e.g., wire, zip tie, cable scrap, nail, etc.).

- Find the highest point, then rotate further until the piston starts to move downwards. -> Place a marker on the swing (e.g., a toothpick, grain).

- Rotate in the opposite direction past the top dead center (TDC) until the piston starts to move downwards again. -> Reset the marker at the swing point.

The "professionally adjusted zeroing" should now be perfectly centered between the two reference points; if it's not, you've found the error causing the inaccurate initial adjustment.

It's actually quite quick and requires minimal effort; at the very least, it allows you to rule out the OT marking as the source of the error.

Regards, Mpire.

Wolfgang, syncro16 wrote:

What else should I do? Actually, everything seems to be working, but maybe there's still something wrong, or should I just ignore it and turn the ESP wheel one tooth further?

Okay. Loosen the timing belt and advance the pump by one tooth.

hi

I'm personally interested to see if that works out. I once tried something similar on my AEL - it has its own separate strap - but unfortunately, there's a space between a tooth and the adjustment mechanism that you simply can't reach in that way...

I'm looking forward to it.

Best regards,

Volvo and T4 have these excellent eccentric tensioner pulleys specifically designed for the water pump and timing chain tensioner.
Not your Volvo?
Furthermore, the camshaft wheel is also continuously adjustable.

cumminsracer wrote:

Volvo and T4 have exactly those nice eccentric tensioner pulleys on the pump ZR for that purpose. Not your Volvo? Furthermore, the camshaft wheel is still continuously adjustable.

Okay, that's essentially how it works. However, if the timing gear doesn't engage properly (which is likely without the right tools), you might try using a notch on the timing belt. I now have a way to hold it in place, so in a sense, that issue is in the past. Also, a notch is several degrees (I once read that somewhere...).
Well, that's not really helpful here!

Regards,

Oh yeah, and who enjoys dealing with the tensioning mechanism? Three times already, the bolt was either poorly glued in or had been repaired in some way - it's unbelievable what some people do. I've now implemented my solution using a M12 bolt - THIS will .

Hello,

Thank you for the numerous responses. I had tried it the way Tagessuppe suggested, but Roorback is right; you can't revert to the previous value with that method. There's a gap.

However, I now suspect that this is completely irrelevant to me, as the problem lies elsewhere.

Could someone tell me, if the value in display field 2 (injection start) is too high during the initial setup, does that mean the injection start is too early or too late? Unfortunately, there is very little information available about this topic here.
Okay, I'm ready. Please provide the German text you want me to translate.
'It also doesn't say that.' I believe I know the answer now, but I wanted to get an independent confirmation.

Hello.
Wolfgang.

Hello,

The TDI timing checker in VCDS indicates whether the injection timing is early or late.

Best regards, Rainer.

Unfortunately, that's not visible in the Screenshot.

http://shop.dieselschrauber.de/vagcom_screenshots.html

I have an older version that can't do that.

Hello.
Wolfgang.

Unfortunately, I don't have a motor like that anymore. Perhaps someone else can post a picture.

In any case, the text below will indicate whether the start of the injection is perfect, too early, or too late.

Best regards, Rainer.

Hi,
How about trying a fully functional VCDS instead of the limited version? It is an excellent fit for the T3 AFN and the Golf.
Small values = late, large values = early.
"In my opinion, the adjustment range of the elongated holes is already larger than a tooth on the ESP wheel, which surprises me."
hg
Herbert.

Well, I've been using my version for over 10 years, and I need something that is absolutely reliable, even in places where there is no service available. While all the additional features of VCDS don't help me in this case, I have to admit that it would have saved me a lot of work if the software had indicated the correct direction from the start.

I had adjusted the pump timing slightly too late, and then the engine wouldn't start. From that, I concluded that I needed to adjust it earlier, but that wasn't possible. However, my conclusion was incorrect. I need to take everything apart now and figure out why it doesn't start when I turn it towards the late setting.

Quote:

Well, I've been using my version for over 10 years, and I need something that is absolutely reliable, even in places where there is no service. All those additional features of VCDS don't help me, although I must admit that it would have saved me a lot of work if the software had indicated the correct direction from the start.

Aha. However, the reliability is quite questionable when there are already problems verifying the start of the funding.
hg
Herbert.

Recently, I had a problem with the AGR (Abgasrückführung) system where the feedback was either too early or too late.
The internal pressure within the pump (as measured) was 1 bar in the low-level condition.

Cause: The pressure sleeve of the pressure regulating valve on the VP37 has come loose. For seemingly unsolvable Facebook problems, here's a possible approach to troubleshooting.