1.9 tdi erratic idle

[Skull]

the glow plugs stay on only when the temperature is below 5 degrees celsium.
for the idle: did you check the fuel lines in the engine bay? if there are too much bubbles, means the pump is sucking air, therefore there is a leak. than try changing the fuel filter.

[s2avant]

Martin,

I had my spare ECU chipped yesterday and it was chugging at idle because the fueling was way too low. It also chugged in gear at low revs. I adjusted it up and it worked fine. Have you got access to vag-com again?

If so go into 1 engine, select LOGIN and enter 12233, then click DO IT, then go into ADAPTION and select channel 1, click READ and see what the value is, then change it in the bottom box to somewhere between 120-125, then click TEST, and then SAVE. (it might not allow you to TEST depends on the ECU)

The engine MUST be warm for it to be accurate. You can see the results in measuring blocks group 1. I've found a figure around 3.4mg gives smooth running without much smoke.

The speed sensor is used by the ECU to smooth fueling while your driving the car. I'll see what I can find in the wiring diagrams.

How erratic is your idle? what revs does it bounce between? I still think the idle fuel quantity needs to be adjusted. I should have had a look at it when we were at Audi Driver but it slipped my mind, sorry

Also when you rev it hard (4500-5000rpm) do you get black smoke from the exhaust?

It possibly something to do with the cylinder fuel quantity corrections the ECU sets up. I don't know much about them yet though so can't tell you a lot more.

My glow plug light on came on for a second and then went out. The glow plugs still work. Now the light doesn't come on at all but the glow plugs still work. I've checked the bulb and that works so I don't know what's gone wrong with it.

As Skull has said the fuel line need to be checked too. I have now had to replace the entire front to back fuel lines. Although they didn't give me a big problem at idle.

Sorry for the rambling post, I hope you can make sense of it,

Ben

[martinjs]

I read on another forum that the glow plug light only comes on below a certain temp so that is ok.
@skull, there are no bubbles in the fuel lines and the fuel filter is new.

Ben, yes i was on adaption channel 1 and the figure was 108. I adjusted it upto 150 i think and it was still 'chugging' but at a faster rate. I'll try again today but with those figures you suggest. The revs bounce from about 850 to 950rpm.
I do get smoke when flooring it, but you can only really see it at night, if a car is following you with its lights on.
I was at mrc on friday, Doug was going to let me try his chipped ecu but mine is the different one (like yours i think).

thanks for the help so far.

[Skull]

what about the third injector? the one with the wire attached. try swapping it with some other.

[s2avant]

108 sounds a bit low. IIRC the default is 128 but this created a lot of smoke on my car. 150 will give loads of smoke I would have thought.

As Skull said it could be an injector problem. I think number three injector would throw a code but it could be a blocked injector.

Doug's car us the earlier type so his ECU won't work. I was supposed to be down at MRC friday but didn't make it until yesterday morning. Well worth getting it chipped, doesn't make it fast by any standards but gives plenty more grunt for overtaking.

I have a spare ECU but it is the IMMO type so you have to program it with vag-com to use it.

My chipped ECU is non-IMMO but doesn't have a barometric pressure sensor in it as I found yesterday not that i plan to drive it up any mountains

Are you venturing down this way again anytime soon? Perhaps we could meet up and try swapping the ECU's and possibly injectors.

Ben

[spink]

Ive heard that the nozzles in the injectors need to replaced after so many thousand miles(100k?) could this be a possibilty?

[martinjs]

The previous owner said he had everything on the fueling side checked, injectors cleaned etc and a smoke test done, of course he could have made all that up.
Whats the 3rd injector? where is it? i dont have a clue about diesels to be honest lol
Ben, im driving back down to london tonight actually but it will be a bit late when i get down your way. Im probably coming back up north again in 2 weeks time.
So did mrc figure out how to chip yours, Doug did say the later ecu was a bit tricky to do. My ecu is 028 906 021D

[s2avant]

My original ECU was an 028 906 021 AP which is the one that got fried the first time they tried chipping it. I got two ECU's as replacements another AP and an 028 906 021 D.

The 028 906 021 D is the one they chipped this time and it works fine. The only problem I have on mine is the barometric pressure sensor as they are external on the D version and internal on the AP version.

As you have a 028 906 021 D they shouldn't have any trouble chipping it.

The third injector is the one with a wiring connector going to it. It contains the needle lift sensor which is used by the ECU to detect the start of injection.

Tonight might be too late for me as I've got to be up for work at 5.15am. I should be about in 2 weeks time though so we'll have to arrange something.

Ben

[martinjs]

Ive just changed that figure to 125 Ben and it is still chugging but at a faster rate. It doesnt smoke either.
RE. the speed sensor problem, could there be something wrong inside the gearbox, whatever the sensor takes its reading from? Even though the speedo works fine... so it cant be that.

I'll be in touch Ben, maybe we can meet up in 2 weeks.

Martin

[s2avant]

Martin. Looks like you've cursed me

My idle is rock solid but I get a serious judder between 2-3000rpm in 3rd/4th/5th.

I've been scouring TDIClub (I assume the judddering thread is yours) but haven't found anything useful yet. I'm going to get on to Jason today and see what he thinks.

Ben

[martinjs]

I didnt mean it... honest.

Try disconnecting your speed sensor out of curiosity.
Yes that thread is about my car, but what i didnt mention is it only judders under light throttle openings, if i floor it it runs ok, it feels like fuel starvation somehow.

It does seem faster now since altering that figure in vag-com. I stormed down the M1 last night in record time i think...lol

What boost levels do these engines run at btw? im getting 0.9bar.

Martin

[Skull]

0.9 is right on the money.

did you changed all the little vacuum hoses?

[s2avant]

I was going to ask you about the part throttle issue. Mine has the same juddering under part throttle. More than half throttle and it flies. It juddered before the chip but it is a lot more pronounced now.

I'm taking it down to see Jason on Wednesday night so we try a few things out. Going to change the fuel filter and filter valve, change the last of the vac pipes and look at that pump pressure valve mentioned on TDIClub. I found the thread that talks about it. I book marked it at work so I'll post it up for you to take a look at.

Also going to change the ECU control relay as that might be the source of my missing glow plug light.

I'll post up any progress we make. After reading up today it seems I might need to up my IQ (Injection Quantity) by a fair bit to compensate for the chip.

Not got a boost guage for mine yet so don't know what boost it runs. 0.9bar sounds about right for stock though. IIRC the turbo maxes out at 17psi and stock boost is way below that.

I really ought to stop fiddling with mine as it's supposed to be my daily driver.

Ben

[martinjs]

Ok cheers Ben. Get it modified lol,
@skull, no not changed them yet, is it just the ones from the wgfv to the turbo coldside and to the actuator? and the 8mm hose to the egr valve

[s2avant]

Right, we had a play last night but didn't cure the problem.

Changed the fuel filter, fuel filter valve and pipework, ECU control relay and ran a bottle of diesl flush through it.

On the plus side it runs better but it still judders at part throttle. Next we are planning to look at that valve on the pump and swap out the injectors to see if that is the problem. I have a set of brand new AFN 110hp injectors at work so these might have to be tried out

I've not got another twist to my dodgy glow plug light as well. It wasn't coming on when I turned the ignition on but it did come on while I was driving it yesterday morning when it was very cold. It wasn't flashing to indicate an error, it was on because the plugs where on! I'm pretty sure this isn't what is supposed to happen though

The old ECU control relay rattled when I shook it so I assumed it was dead. Now the new one is in the glow plug light flickers for an instant when you turn the ignition on and still comes on after you start driving (if it is very cold).

Any clues on this one?

Ben