1.4 16v tickover/idle rpm

[isambard]

Hi guys, apologies busy schedule means I am slow at replying!

I will try to describe the issue a bit more clearly: assume i am in very slow traffic; slower than crawling speed so start/stop.

If i want to move forwards i press the accelerator and depress the clutch for a moment, and then cruise for a few metres.

As i cruise the revs go back down towards 680, then dip a bit more towards 500, before bouncing back up to 680.

 

I have read about cleaning the EGR system on this website, but not sure where it is! Please could you point me to it on this picture of my engine? Also the purge valve mentioned

Thanks as always for all the help guys

[Breezy_Pete]

Purge valve ringed in green, EGR valve ringed in blue.  Note though that the metal pipe from the EGR valve to the inlet manifold (entering just beneath the throttle body) is the thing that needs cleaning, at the throttle body end, there's rarely anything worth cleaning off inside the EGR valve itself (cos it runs so hot it self-cleans).

 

 

 

Here's a guide to EGR cleaning on the AUB, a bit more complex than on yours as there's an intermediate plate between TB and manifold that doesn't exist on yours, I think.  Your EGR metal pipe will go straight into the inlet manifold horizontally on the battery side of the manifold.

Edited 29 March, 2017 by Wino

[Breezy_Pete]

Here's the entry point, two (Torx?) screws to remove from manifold (and maybe a support bracket to disconnect near/on the water fitting?):

 

Edited 29 March, 2017 by Wino

[Taylor93]

Isambard, I made a How to Guide on cleaning the EGR system on a 1.4 16V AUB engine code, there may be slight differences, but should still help.

 

 

 

hope this helps

[isambard]

Thanks both for the replies, very helpful

I realistically won't get chance to do this until next weekend, but i'll let you know what i find out!

[indars]

 

BBZ engine of my Furby = ~740rpm after warm-up; same 10 years ago and now (but that's just according tachometer in dashboard).

[Breezy_Pete]

5 minutes ago, indars said:

 

BBZ engine of my Furby = ~740rpm after warm-up; same 10 years ago and now (but that's just according tachometer in dashboard).

Do you have VCDS? Can you check if that agrees with the specified value in measuring block 50/2 of engine module?

That would probably demonstrate that the erWin info I offered earlier does have errors in it.

[indars]

14 minutes ago, Wino said:

Do you have VCDS? Can you check if that agrees with the specified value in measuring block 50/2 of engine module?

That would probably demonstrate that the erWin info I offered earlier does have errors in it.

 

Have no VCDS- but have Xtool VAG401 (=poor man's VCDS :-)

Will take a look in evening; but for me, those rpm sounds/feels totally perfect. And yes- feels like indications in dashb.not really match with reality.

Example from winter, when was fighting with EGR: coolant t* in dashb.goes quickly to 90*C- but scan tool shows only 60...70*C > and it rises very very slow when idling.

And final proof of it is that hot air in cab comes after longer period (despite in dashb.there's rocksteady "+90*C" quite quickly).

[Breezy_Pete]

I wonder if the rpm numbers for BBY/BKY and BBZ in the table are the opposite way round to how they should be. That would make sense with respect to the AUA/AUB difference.

[indars]

9 hours ago, Wino said:

I wonder if the rpm numbers for BBY/BKY and BBZ in the table are the opposite way round to how they should be. That would make sense with respect to the AUA/AUB difference.

 

BTW, found that table too > for emission test, some rpm interval is given.

Here's mine warm idling = same view last 10 years (bit' bit' under 750min-1). At same time scanners shows ~690.

Coolant t* (as per scanner) was 75*- and it's after 1H driving in normal city traffic, when gauge on dashb.showed steady 90* :-)))

[indars]

On 3/29/2017 at 17:39, Wino said:

Here's the entry point, two (Torx?) screws to remove from manifold (and maybe a support bracket to disconnect near/on the water fitting?):

 

 

For BBZ it's kind of Sudoku to get pipe out without dismounting everything else- but it CAN be done without breaking a pipe ;-)

[Breezy_Pete]

There's probably good enough access with the throttle body removed to clean out the tip of the EGR pipe without taking it out of the manifold? 

 

Your (scanner) rpm number suggests that your tachometer gauge is reading a little high, and that 680 really may be the specified value at full operating temperature, for your engine.

I did a log on Tuesday afternoon that gave a specified idle of 706rpm at 75C coolant temp (which happened after 10 minutes of driving). Once mine reaches 82C (11 minutes), the specified idle stops going down, staying at 678 for the rest of the journey, except for a time when I switched on the A/C, where it jumps up to 750 specified.

 

Your thermostat is maybe getting old?

 

 

Edited 31 March, 2017 by Wino

[sepulchrave]

Yeah, the CTS sensors used are really not very accurate, thermistors drift badly, you're looking at something around 10% at 100C in a good quality thermistor, there will be a simple algorithm in the ECU to account for this inaccuracy but it won't cover an aged low-grade device like the CTS sensor.

Thermostats are actually pretty accurate until they go wrong because the melting point of the wax is very consistent.