my 02 golf 150pd is giving me major problems, when it reaches 3000rpm it starts to judder (heavily) and throws out black smoke and wont go over 3000 rpm, i then have to change gears before any form of acceleration is possible, more recently their is sometimes a conplete loss of power, it then takes upto a few seconds (sometimes upto 30 seconds/sometimes longer) before it even accelerates normally in an idle state.
It also goes into 'limp mode' on motorways where I struggle to reach anywhere near 60mph!
I was told that it was my boost pipes, so I replaced 2 that a mechanic thought looked loose/worn but to no avail, took it for an mot yesterday and it failed on the emissions test!
Since the above, i have taken it to a VW specialist (VW trained) who hooked it upto the laptop, a tempreture sensor fault came up, which has been replaced, he also replaced my MAF with another one to see whether that was faulty, he then went to reset codes when a fault code came up
16688- injector 4 intrmittent misfire???
any idea's is it simply a case of replacing, or is there other possible trouble shooting i can do to rectify the fault??
Any help would me much appreciated
please take into consideration I am not very clued up on terminology or technically/ mechanically gifted when it comes to motors! So I apologise if I've missed anything or come across a but thick!!!
Thanks in advance for any suggestions
Edited by Dynamic Dave on 31/01/2010 at 00:30
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I'd be taking a very careful look at the injector loom within the head.
659.
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As 659 says, these VAG PD motors run the wiring for controlling the injectors INSIDE the cylinder head, not outside, and the insulation can break down with the heat / working conditions.
Before you dive into that, at the end of the cylinder head there's a big electrical connector that links to the injector wiring. It's secured by a screw collar, and this connector can get loose / dirty / contaminated and cause problems.
Unscrew the collar (it's half a turn if I remember right) and remove the plug, then spray the connectors with contact cleaner (NOT WD40, but electrical contact cleaner). Then unplug and replug the connector a few times before reconnecting properly.
If that does nothing, then as 659 recommends, look at the injector wiring itself.
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But you may set a fault code when you disconnect the injectors - be prepared to deal with this.
659.
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Thanks for the replies, I went to see the mechanic and asked him about the injector loom, he said it's most likely the injector itself (from the faultcode) he said he would look at as I have it booked in for Thursday. He is charging £140 to replace injector with a 2nd hand one.
My problem is I am a novice when it comes to car engines and so wouldn't know where to look to see if there is a loose connection? Arethere any guides to walk me through the process?
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It sounds like your mechanic is genuinely trying to help. There aren't any guides that I know of, unfortunately.
To be honest, if he's already lifting the rocker cover & camshaft to get at the injector it may be worth asking him what the additional cost of having the injector loom replaced is, all at the same time.
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PD fuel injectors are many times more reliable than the loom which connects them to the vehicle wiring harness. (They also cost a lot more).
What's the evidence for a proposed injector swap? Fitting second hand injectors is possible on this engine as the control software has the capability to adjust the injection quantity to match that of the others. This is done by measuring the engine acceleration between firings (Delphi please note), but I wouldn't recommend random injector switching.
Faulty PD injectors are a very rare occurance.
659.
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are the injectors and the injector looms located in a similar position? When I mentioned the loom to the mechanic he said he would have to look, but wasn't convinced? So my question is if he goes to replace the injector would he be able to inspect the wiring looms at the same time? Thus allowing him to see which of the 2 is faulty???
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He has to lift the cam cover to do either job, and I believe that he can inspect the condition of the loom while he is in there.
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Can confirm that loom can be a problem on these motors, especially at this sort of age. Injectors CAN give trouble, but less commonly, they are pretty reliable. Without inspecting its impossible to say one way or the other, but if the mechanic has some experience on these engines (which he should, they are common enough) they work with him to try to fix it.
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I would be heading to a new loom, particularty as you had the problem and it did not set a log a fault code, typical of a harness error. Inspection will not reveal anything. You can read about this fault on the vwaudiforum.co.uk in the golf and passat sectios. There is a step by step guide there with tips, like warm the new harness and tray with a hair drier immediately before fitting to avoid it cracking when you bend it to install it. Regards Peter
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You could look at section "e" in the attached: www.tdiclub.com/TDIFAQ/TDiFAQ-8.html#e
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The best way to identify a faulty injector loom is to remove the rocker cover and connect an analogue meter (AVO) set to the Ohms range to the multi way connector on the head. All the injectors are wired individually to this socket - 8 wires.
Select an injector and with a pair of long nosed pliers, move the wires where they emerge from the relevant injector socket. You will then see any intermittency on the meter.
Failure at the back of the big multiway connector seems to be less common.
659.
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The best way to identify a faulty injector loom is to remove the rocker cover and connect an analogue meter (AVO) set to the Ohms range to the multi way connector on the head. All the injectors are wired individually to this socket - 8 wires.
This is the way we do it.
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Taken the car into the garage today, asked him to check the looms and asked him how he would check them (tried catching him out to see if he knew what he was doing) he said he can check for continuity (using ohm meter) so asked him to check it over and if need be to replace while it's all open anyway, I'll pass on the feedback later, hoping it all goes well, fingers crossed it resolves the issues!!!
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Update...........
Just got back from the garage he checked the injector wiring looms and said they seem fine, took the injector out, replaced it but it ran worse (2nd hand part), then opened it back up and replaced it with another, my luck that was also faulty so he put my old one back in!! Luckily he was honest and didn't charge...
So does anyone know of a reputable place I can get a injector for my ARL 150 PD engine???
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hi all,
as i updated earlier, changed the injector with 2 second hand ones no joy, mechanic thought both of them were faulty (being second hand), went back to him and got him to change my number 3 injector (known to be working) with the 'faulty; number 4 injector, and at the same time replace the wiring loom.
But the vagcom still gave the 16688 injector 4 intermittent misfire code????
Since the work the car is smoking very heavily, especially when first started and when idle???
please help!!!!!!!!!!!
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