Kaltstartproplem beim 1Z nicht gelöst *heul* | Posts 80+

Hi Uwe!

Nö! Entweder Handbremse oder keine!

Best regards, Christian.

haehnlein wrote:

"When I briefly increase the idle speed to 1500 rpm, either with a cold or warm engine, the RPM sometimes drops back to 1000 rpm, and during that time, the engine makes a somewhat faster, relatively low-pitched sound: 'wrrum wrrum wrrum wrrum wrrum' (please don't laugh... it sounds kind of like an old school bus). This condition lasts for a few seconds, and then it returns to normal at 800 rpm."

Hi Christian,

It seems like these are normal fluctuations.

This kind of issue could potentially originate from a stiff or even jammed switch machine, or from a malfunctioning point frog adjuster.
Oder sogar von einem zwecks Tuning verschobenen Stellwerk . . .

If the speed clearly increases and decreases in a consistent pattern, it's likely related to the throttle mechanism. However, if the main change is in the engine tone (becoming harsh or soft), it's probably due to the fuel injection system.

ulf wrote:

das scheinen mir Regelschwingungen zu sein.

Hi Ulf,

I also believe the problem must lie with the ESP (Electronic Stability Program)... In any case, wear on the swirl flaps and the glow plug system have been ruled out. The other day, when it was -10 degrees Celsius, the engine started immediately after two attempts using the glow plugs; yesterday (the engine was warm), but after 1.5 hours, it only started with a lot of throttle and smoke...and this happened in several cases!!!

Air in the ESP system is definitely ruled out because otherwise, a longer preheating time when the engine is cold wouldn't be able to "fix" the problem.

ulf wrote:

"This kind of issue could potentially originate from a malfunctioning or even damaged switch machine, or from a jammed point machine." Oder sogar von einem zwecks Tuning verschobenen Stellwerk . . .

According to Henzo, a stuck injection timing adjuster would be the cause. While I'm not a pump specialist, doesn't the injection timing adjuster change the fuel delivery start time, especially during a cold start? This means that with a slightly warm engine, it should theoretically cause fewer problems than with a completely cold engine, which isn't what we're seeing.
I certainly hope that no one has modified the mileage beforehand (which I also don't believe -> everything matches in the vehicle registration document and the VW service booklet ).
"The last major inspection by Volkswagen was performed 10,000 km ago, and there were no repair recommendations at that time, which likely indicates a lack of error codes (my adapter similar to ULF is still not finished)."

ulf wrote:

Wenn dabei eindeutig die Drehzahl im gleichen Rhythmus steigt und fällt, dürfte es eher das Stellwerk sein, wenn sich hauptsächlich der Motorton ändert (hart / weich), wohl die Spritzverstellung.

I also believe that the amount of fuel injected at startup is insufficient, and that prolonged preheating resolves this issue (for a given amount of fuel, it creates much higher temperatures in the air cushion than intended by the EDC). Furthermore, when the engine is already warm, the amount of fuel being injected is also not sufficient for the current temperature, which leads to smoke and misfiring during the first few seconds.

Now, the question naturally arises: what should be done ?

If the master switch is faulty, a new pump will be required!
If the Microsoft Store is running slowly, you might be able to fix it with a system cleaner (although I'm not sure if that will work!).

Or you can ignore the whole thing (then the exhaust won't rust as quickly from unburned diesel ), as long as it doesn't damage the engine! That reminds me of my old Passat TD, manufactured in 1985: which actually got better and better over the years .

@everyone:

Thank you for your knowledgeable answers in the forum; I quickly understood the TDI principle, and I can't thank you enough!

Best regards, Christian.

Hi.

In the past, there was sometimes a phenomenon with starters where hot engines would no longer start. The starter motor wouldn't make any sound at all.
Everything was great when it was cold.

The cause was an electromagnetically "undersized" magnetic switch: The copper winding has a positive temperature coefficient, meaning that less current flows through it when it's hot compared to when it's cold.
And sometimes, the small amount of hot air was not enough to move the magnetic pusher against light burrs and old grease .

If something similar is happening with your fuel injector... perhaps exacerbated by transition resistances? And does it only open sufficiently after prolonged shaking during starting, allowing the full amount of fuel to be injected?
Please measure the voltage difference between the terminal pin of the fuel shut-off and the positive battery terminal while the engine is running.
Approximately 1 volt is normal due to the semiconductor switch in the motor computer, but anything above 2 volts gradually becomes a cause for concern.

Or simply disconnect the normal cable from the charger and connect it directly to the positive terminal of the battery before a warm start.

Have you ever tried a cold start by connecting the glow plug cable directly to the battery?

Hi Ulf!

ulf wrote:

In the past, there was sometimes a phenomenon with starters where hot engines would no longer start. The starter motor wouldn't make any sound at all. Kalt war alles prima.

I know all about that! But at some point, the problem also appeared intermittently – the ignition would click on and off ten times, and then it would start. Using fuel additives only provided temporary relief...

ulf wrote:

Oder zieh einfach des normale Kabel vom Absteller runter und verbinde ihn vor einem Warmstart direkt mit Batterie+.

I will definitely try that out tomorrow!

ulf wrote:

Hast Du mal einen Kaltstart mit dem Direkt-Glühkerzenkabel zur Batterie probiert?

The crafting wire is here, but the cold weather and lack of time have thwarted my plans – I'll get around to it eventually (though it's probably not that urgent, as the poor hand-warming performance should rule out any issues in that area!).

Best regards, Christian.

Hi Christian,

haehnlein wrote:

Hi Ulf! ulf wrote: In the past, there was sometimes a phenomenon with starters where hot engines would no longer start. The starter motor wouldn't make any sound at all. Kalt war alles prima. I can certainly relate to that! But at some point, the problem also appeared without any warning -> the ignition would click on and off ten times, and then it would start! Using additives only provided temporary relief...

With only ignition on and off, the starter motor should not react, because it is only activated by terminal 50 of the ignition switch (ignition = terminal 15) .

Quote:

ulf wrote: Hast Du mal einen Kaltstart mit dem Direkt-Glühkerzenkabel zur Batterie probiert? Das Bastelkabel liegt hier, aber die Kälte und die Zeit haben mir einen Strich durch die Rechnung gemacht->wird aber noch nachgeholt (iss aber wahrscheinlich nicht so dringend, weil der schlechte Handwarmstart diesen Bereich ausschließen sollte)!

You are probably right about the bracketed statement - on the other hand, the "phenomenon" that cold starts improve with multiple pre-glow cycles remains. In my opinion, this suggests that alsosomething is not quite right in the glow system --> a voltage drop between the battery and the glow plugs, which is "compensated" by excessive pre-glowing...

ulf wrote:

With only ignition on and off, the starter motor should not react, because it is only activated by terminal 50 of the ignition switch (ignition = terminal 15)

Hi Ulf,

In my case, the magnetic switch was stuck. Due to the rapid on-off cycling, the "iron core" started moving (audible through a clicking sound). After a long journey, it eventually worked, or a good whack on the magnetic switch . Also, the starter motor failed in cold weather and after a long drive when starting (brrrrrrrrrrrrr)-> this was due to a worn-out bearing (but I ignored it for 8 years).

ulf wrote:

Mit dem Klammersatz hast Du wohl einerseits recht - andererseits bleibt das "Phänomen", daß der Kaltstart mit mehrmals Vorglühen besser wird. Das deutet IMO darauf hin, daß auch im Glühsystem etwas nicht ganz stimmt --> Spannungsverlust zwischen Batteie und Glühkerzen, der durch überlanges Glühen "ausgeglichen" wird . . .

Of course, I wouldn't completely rule that out. I can't examine the temperature sensor yet because the potentiometer on your adapter is broken, and I won't be able to get a new one until next week.
I also have to postpone the delivery tests until tonight because there is absolute black ice here .

Best regards, Christian.

Hey everyone!

I've been following this thread for a while because my car is experiencing similar problems (cold starting after more than 48 hours requires multiple pre-glow cycles and produces a lot of white smoke; however, if the car sits for less than 24 hours, there's only a little bit of white smoke. A warm start is always possible without any issues). I've already checked my glow plug system and temperature sensors, and they seem to be okay.
Then today I compared the target values from the error database with my own data and found some questionable things.

1) Engine idle speed is not constant; it fluctuates between approximately 856 and 910 RPM.

2) Idle speed control: Cyl1: +3.2, Cyl2: +3.6, Cyl3: .2 and no indication for Cyl4.

3) Air mass at idle: 465 instead of a maximum of 420.

4) Injection timing at idle speed with the engine running: 17°.

'When I increase the engine speed and it goes above 1500 RPM, I can no longer read any values with VAGCOM.'
The other values are all within the expected range.

Okay, so my question is: Is my adapter faulty, or what are some possible reasons for these values? Thanks in advance for your answers!

Best regards,
Wolfgang.

P.S.: I have a 1994 Passat 1Z with 175,000 km on it, and everything is original except for the air filter (which has been changed) and the EGR valve (which is faulty).
P.P.S.: A heartfelt thank you to the authors of the threads: 'Methodical Troubleshooting,' 'Error Databases,' and 'Diagnostic Adapters!!'

Hi Wolfgang,

NVE wrote:

1) Motordrehzahl im Leerlauf nicht konstant. schwankt zwischen ca. 856 und 910!!

VAGCOM doesn't resolve to within +/- 1 rpm; it operates in steps of approximately 20 rpm. Therefore, jumps of 20 rpm are normal when the actual speed is close to a gear shift threshold and even exhibits only minimal fluctuations.
Around 60 rpm fluctuation seems a bit unusual to me.

Quote:

2) Idle speed control: Cyl1: +3.2, Cyl2: +3.6, Cyl3: .2 and Cyl4: no reading displayed

.
That's quite a bit of wear and tear. It could be caused by worn nozzles and/or poor compression. Have you already tried the on-the-go test (see "Tips for used items")?

Quote:

3) Air mass at idle: 465 instead of a maximum of 420

Comes from the faulty EGR valve, but it's okay.

Quote:

4) Injection timing at idle speed with the engine running: 17°

Way too early! That might be contributing to the starting problems.
Just to be on the safe side, double-check that the crankshaft pulley timing wheel isn't twisted (a common issue with older 1Z engines).

Quote:

5)Wenn ich die Motordrehzahl erhöhe und über 1500 komm, kann ich mit VAGCOM keine Werte mehr auslesen.

Do you have any unnecessary programs running in the background? Have you tried adjusting the different trim settings on the adapter (for the opto version)?

Hello Ulf!

Thank you for your quick response!

I had the compression checked when I bought it (2 years ago), but it was done by measuring the voltage and current during startup, not with a pressure gauge. At that time, the compression was relatively balanced.

Regarding the injectors: I've noticed that it seems to be consuming a bit more fuel lately, and there are unusual smells coming from the exhaust. However, the performance hasn't changed.

Zum Kurbelwessenrad: Hatte kurz nach dem Kauf einen Schaden am Rad den ich selber durch austausch des Zahnrades und der Schraube, behoben hatte. Allerdings vor ca. 4 Monaten hatte ich den selben Fehler nochmals. Hab dann in der Boschwerkstatt die Kurbelwelle abfräsen lassen und ein neues Kurbelwellenrad mit neuer schraube und schraubenkleber bekommen. Ich schätze mal dass seit dem der Verbrauch bzw. wahrscheinlich auch der Einspritzzeitpunkt so schlecht ist. If it turns out that the mechanics didn't check the fuel injection timing before returning my car, I will have to file a complaint.

Regarding the adapter: I don't think that open text documents will significantly degrade system performance, and besides, my device should be fast enough (it's brand new). Unfortunately, I can't change any settings on my adapter.

I'll try again tomorrow and also check if the timing belt tension is correct!

Best regards,
Wolfgang.

ulf wrote:

Injection timing at idle with the engine running is 17°. That's far too early! This could be responsible for the starting problems. Just double-check to make sure the crankshaft timing pulley isn't twisted (a common issue with older 1Z engines).

Hi Ulf, hi Wolfgang,

...then the start of injection must be set too late!!!??? -> Due to knocking, the crankshaft rotates ahead (the timing belt pulley rotates counter-clockwise relative to the crankshaft) -> Diesel fuel is injected when the piston is moving downwards.
Hab`s noch nicht geschafft die Abstellertest`s durchzuführen!!

@Wolfgang:

What was the issue with the crankshaft pulley on your car? Was the old 8.8 screw still in place when you bought it, and had the stub been worn out as a result? How did you notice this problem?

The new screw is installed in my car, but if the stud was already stripped before, then things will be interesting at the vehicle inspection tomorrow.

Here's an interesting link for everyone interested in crankshaft sprockets:

http://home.arcor.de/sgrafen/salatoel/kw_schraube/kw_schraube.html

However, there are errors in the torque values.

AAZ, 1Z, AFN (same for all):

Crankshaft bolt: 90 Nm + 90°. Hexagon socket head screw: 25 Nm (Source: Erwin repair manual for VW Passat!!!).

Best regards, Christian.

@ haehnlein

Hello!

Naja, der Kaltstart ist schleichend immer schlechter geworden, solange bis er nach 10 Startversuchen unter extrema Rauchentwicklung (schwarz) nur sehr langsam zu starten war. Das hat sich fast so ängehört als würden die cyl nacheinander in Betrieb gehen. Als dann nach kurzer fahrt der Motor sich von selbst abgeschaltet hat, hab ich ihn dann in die werkstatt geschleppt. Hatte noch die alte schraube drinn und das Kurbelwellenrad war total ausgeschlagen und der Zahnriemen um ein zwei Nuten gesprungen. I was incredibly lucky that it didn't slide any further, or that the gear didn't slip.

The KW strut was a bit damaged, but since I didn't know anything about this forum or the problem, and I only knew a little about TDis in general, I simply installed a new wheel with a new screw, and it actually worked great afterwards. However, it didn't last long.

Nach ca einem halben jahr, weiß nimma so genau, hatte ich wieder Startschwierigkeiten, Weißrauch und zwischenzeitliche Motorrucklen inklusieve starker Leistungseinbußen, bzw. Graurauchwährend der Fahrt(siehe Thread Weißrauch 1Z)! Konnte mir aber nicht vorstellen, dass sich der selbe Fehler in so kurzer zeit wiederholt. Naja, nach langem suchen wars dann wieder das KW-Zahnrad und diesmal ließ ich den Stumpf nachbearbeiten und neues Zahnrad und neue Schraube mit Schraubenkleber einbauen (Bosch). Seit Einbau bemerkte ich nur das der Spritverbrauch etwas mehr war und wenn das auto lang gestanden ist, hatte er kurze Startschwierigkeiten, aber kaum der rede wert. Und seits bei uns so kalt ist hab ich wieder Startschwierigkeiten (siehe oben)! I hope I don't... If you're making the same mistake again, then a new crankshaft would be necessary...!!

Best regards,
Wolfgang.

haehnlein wrote:

ulf wrote: Injection timing at 17° with the engine running in idle. That's far too early! This could be contributing to the starting problems. Just double-check to make sure the crankshaft timing pulley isn't twisted (a common issue with older 1Z engines). ...dann müßte der Förderbeginn doch auf zu spät stehen!!!???->durch Auschlagen rennt die Kurbelwelle voraus (Zahnriemenrad verdreht sich gegen den Uhrzeigersinn relativ zur Kurbelwelle)->Diesel wird bei "runtergehendem" Kolben eingespritzt.

Hi Christian,

Theoretically, you are correct, but if the rotating masses, for example, oscillate back and forth along the crankshaft due to the opening and closing of the valves as part of the gear mechanism, then that may not necessarily be true anymore...

Hi everyone!

Okay, please provide the German text you would like me to translate into English.

He survived the ASU (Annual Service Update), and the turbidity was measured at 0.27 [1/m]. This is 0.02 higher than the last reading taken 100,000 km ago, which suggests that the nozzles are not quite perfect anymore, but overall it's still acceptable.

@ Ulf:

"Attempts to disconnect the cable were unremarkable (voltage difference of 0.4 volts with the engine running; disconnecting the cable directly resulted in no change)."

Before taking the car for its inspection (ASU), I let it run and noticed that: it started to jerk at 3000 rpm .
Now, of course, I don't have the new injectors that my dad installed anymore, and it could be the NBF (Negative Feedback). However, the 3000 rpm test is normal. A friend of mine had a faulty NBF, but in his case, the misfire was more like an intermittent stall, whereas in my case, it's more subtle (-> incorrect fuel delivery).

The idle speed fluctuations also occur occasionally, and during these fluctuations, the tachometer needle oscillates slightly (duration approximately 5-20 seconds).

Okay, I remember a post by Ulf about "pump knock" (-> search function). What's written there makes me increasingly suspect an ESP issue. Unfortunately, my diagnostic adapter isn't working properly yet... but a worn distributor piston definitely wouldn't show up in the error memory. Maybe I should try adding a good amount of diesel cleaner, even though I'm skeptical.

The LMM (likely referring to a mass airflow meter) is supposed to cause stuttering, but shouldn't it play a minor role when starting the engine?

Best regards, Christian.

haehnlein wrote:

Ein Kumpel von mir hatte einen defekten NBF und bei ihm war das Ruckeln aber eher aussetzermäßig und bei mir ist es eher weich (->falsche Spritmenge).

Hi Christian,

"Soft" jerking or stuttering often actually comes from the mass airflow sensor (MAF), although I still don't understand which (regulatory) cycle could be triggered by it.

Quote:

The idle speed fluctuations also occur occasionally, and during this time, the tachometer needle fluctuates slightly back and forth (duration approximately 5-20 seconds). Nun kann ich mich an einen Beitrag von Ulf erinnern über Pumpenruckeln (->Suchfunktion). Was dort geschrieben steht lässt mich immer mehr auf ESP tippen.

It seems to me that it's the most obvious solution right now...

Quote:

Unfortunately, my diagnostic adapter isn't working properly yet... but a worn distributor piston definitely wouldn't show up in the error memory. Maybe I should try adding a good amount of diesel cleaner, even though I'm skeptical.

If the adapter is running, you can use it to adjust the initial amount. If the reduced flow rate is due to pump wear, I believe this should be compensated for by increasing the target value accordingly.

Quote:

Der LMM soll ja auch zu Ruckeln führen, aber beim Starten sollte der doch keine große Rolle spielen!?

It's probably true that the MAF sensor signal is ignored during startup, as far as I know.

Hi Ulf,

I experienced the following phenomenon today as well, which likely indicates a problem with the ESP (Electronic Stability Program).

While driving with the engine idling cutoff feature enabled (5th gear at approximately 80 km/h) and suddenly accelerating, nothing happens for about half a second, then there's a slight jolt, and a small white flag pops out from the rear. However, I've only noticed this when the engine is cold.

Wenn nun ein klemmendes Mengenstellwerk die Ursache ist, sollte es doch kein Problem sein einfach die Sache zu ignorieren? Oder war da nicht mal was mit Bertil`s 1Z (->liegengeblieben)???

Perhaps it's enough to simply increase the base value using VAG-COM? However, you'll need to give me some time (-> adapter and learning how to use the program).


Unfortunately, it seems to be common practice today in many areas that the customer is the (of course, unpaid) guinea pig.


Best regards, Christian.