Injector nozzles wear out over time...I'm not sure on the history of mine so I have some bosio pp520's waiting to go on when required
With the engine up to temp and idleing, slacken the union nut which bolts the injector pipe to the injector, very very slowly until diesel starts to leak/spit out. If the injector/nozzles are good, the engine will fluctuate more and sound rougher, or if it is faulty or worn it will make little or no difference atall. Do this for each injector. Be very careful not to slacken too much, just enough to bleed off a bit, and obviously be prepared to have to clean up after. Its not exactly a scientific test, but its a good indicator of a bad injector. Remember that a siesel works in a wide afr and so a faulty/dribbling injector can show up as either poor mpg, excess smoke, knocking and/or slight lack of urgency/power, but will still drive ok.
Interesting. I guess that's the diesel equivalent of pulling one plug lead at a time to see if the idle changes. I think I'll put on some goggles first, but will give it a try this week.
Worth a go, yeah take great care, due to the high pressures, the nut only need slackening until just a small amount if diesel seeps out, and dont rev or have the revs high while trying it, purely at idle.
I had a look at this tonight. The idle changes on every cylinder - maybe slightly less on No1 than on the others, but it's not a very exact test. Still got a faint taste of diesel in my mouth The previous owner had chucked some Forte diesel conditioner additives through it when trying to sort out the idle problem. He thought the pump was on its way out... he might still be right, but I wonder if it's putting some proper injector cleaner through there... if the BG stuff is the most aggressive, maybe I'll start with that, as it's fairly long in the tooth, had a fair few owners, etc... You never know if someone's been running it on homebrew fuel / red diesel / heating oil... You wouldn't catch us doing that, eh lads?! I checked the fuel filter too, and made sure the water trap was fine - only a tiny bit of water in there. I also noticed that it does indeed have the odd bubble running down the inlet pipe towards the pump (before I started messing with the filter). There's no sign of a leak that I can see though. What's the likely diagnosis for that? I also changed the EGR adaptation value on VAGCOM - it wouldn't let me set it above 154. I guess that's better than 128 though?
Maybe is different for older Audi's? Either way, the highest value is what you need. Try and video how much air mike, the return piece is a usual suspect for air ingress at the fuel filter
Reducing chances of fuel line air leaks was dealt with in StuMc's thread. Post below. http://www.clubgti.com/forum/showpost.php?p=1979339&postcount=27
A brilliant idea that I had seen another similar filter for 16 on another site so I'll get a price for one of these rover 600 filters later as I'll be in halfords this afternoon EDIT: the golf filter is 22 and the rover filter is 16 online, I'll report back with trade card discount applied later
Il second that, did it to mine, sorted an annoying slight air bleed problem on mine, either a rover 2.0 Di filter or land rover freelander 2.0 di filter will do. I found the freelander one to be cheaper strangely. Your right the injector test isnt an exacting test, its more to identify a hugely out of spec injector, if you can eally notice the difference then they are all within spec of each other, probebly worn and due a recal' but not the cause of your idle problem.
Just done the guide, I only have the free vcds so I had to get a passenger in the car to note the peak readings for me. Maf peaks at 847.9, and reads between 508 and 532 at idle. So I guess this is within spec??? EGR max value was 154 on my older ecu, I can confirm egr valve is now totaly inactive. Idle is at 841-861 Idle IQ is 2.4-2.6............bit low?? Boost sits at 1040-1050 at idle, which is correct, but peaks at 1942. Test done in 3rd gear. So im guessing I have a small boost leak somewhere? Strange thing is, car pulls like a train lol
Maf readings are all good...your specified and actual will be different after the egr delete, this is normal...your maf reading will rise from 380 to around 500 at idle after the delete has been successful Idle iq should be between 3 and 4 ideally...maybe upping this will up your boost level as well as fuel and boost are linked...either that or your passenger is seeing the hold and not the momentary peak caused at 1900rpm Did you check your pump timing while you were plugged up?
The audi filter is different. It's a screw on unit under the bracket which holds all the pipework - a bit like a canister type oil filter. So there's no need to disturb the pipework. I'm trying to upload a video to photobucket, which I took to share the sounds of the injector test. It also shows the odd bubble going down the pipe towards the pump. I did some googling and it seems to be a big problem if it's bubbles in the return line, but I'm getting air bubbles in the inlet pipe, heading towards the injection pump. Edit.... the nutcracker video! And a short vid of how VAGCOM readings are moving around. I tried holding the engine speed at different positions to demonstrate how the RPM values seem to be consistent some of the time, but not at idle.
I cant check pump timing, I need to buy full vcds for that, which isnt going to happen at the mo until I find a new job, its on the to-do list lol. That was what it peaked at for boost. I might go and see if it will allow me to up the IQ, it let me adapt the egr so I dont see why not. Yeah mike a vid or soundbite would be good
sorry by the way mike, not trying to hijack away from your problem, just trying to get advice in the same thread. Just listened to your vid, you definitely have characteristic tractor chatter, im confident its an injector problem, possibly an imbalance or a blockage. I say tractor chatter because the tractor on the farm I worked on a while back used to constantly have that idle problem, almost like a 3 cyl, and it turned out to be blocked injectors 2 and 4
Not my thread!! I just thought the idle issue I have is quite common in older diesels (from what I read) so would be worth discussing in the FAQ thread... I imagine yours falls into the same bracket.
Which version are you on? I'm only on V7.04 or something, and that does pump timing. If you find yourself up near Windsor, let me know and we can have a look at the timing on yours.
I downloaded it about a year ago so could be an old version, I will delete and install again. I may take you up on that if this does not work Edit: Nope, doesnt have it unless you pay to register.
