well we replaced the engine speed sensor with a new one, figuring that may help as it did run a code for a little while ago, didnt make a difference still has the missfire on idle all the way up to 2000rpm, the engine should be broken in this week hopefully so we will see if the missfire is any higher in the rev range, ive read on the net here (not so much on the fourm) about a power distribution relay also being called relay 109 causing simmilar effects, but i find it hard to think that a relay would be causing a missfire. must say im starting to get stumped on this one
Do you think that it may be one cylinder giving you trouble or are all cylinders misfiring at random? If it's just one cylinder it's probably an issue with the injector as long as everything else with that cylinder is fine. Just a tiny piece of dirt can clog the newest of injectors.
I have narrowed down a misfire before by putting my hand on the exhaust manifold soon after start up. If one of the runners is cooler than the others, start with that cylinder.
Another way to check this but not recomended because of the dangers of high pressure diesel, is to crack the injector lines one cylinder at a time and listen for a drop in rpms. No drop means that cylinder isn't firing.
If it is all cylinders then I would think of what affects all cylinders, for example the lightened flywheel.
I've heard of other guys runnin these lightened flywheels on the tdi's and have had no issues, so I find it hard to believe that the flywheel is my problem. The car runs excellent otherwise. I personally think it might be an injector (not saying Giles isn't good at what he does, because he is. But there might be a little piece of dirt or whatever in one of the injectors). The strange part is the "misfire" only happens at idle but more noticable when driving between 900 - 2200rpm because it's underload. And it smooths out between 2200 - 2800rpm then after that it gets rough again. It's boggling my mind lol.
If you have scanner that can read measuring blocks, there are channels where you can see fuel delivery etc at each cylinder. I would check there. Actually check all the measuring blocks .
Are you the guy that came to the shop and asked for a set and then Giles said there are only 3 ready, but then looked on a bench and saw a set of 4 that were in progress? He tested the missing one (#3) and the pressures looked good so he gave it to you?
Was I in the shop that day?
No that wasn't me Tyler. I got my injectors done about a month and half ago, but they have only been in my engine since I got it running about two weeks ago.
measuring blocks seems to be good place to start to check fuel delivery, and its not the flywheel, that would be more of a shudder this is a dead miss.