95 TDI hesitation / misfire / stutter

[The Noble Gnome]

Hi,

Looking for some help with an intermittent problem on an other wise untroubled and very reliable 1995 Passat TDI.

I have been troubled on occassions by the engine seeming to stop very briefly (probably less than a second) usually on the motorway, above 60mph, both while accelerating and cruising.

I have been searching around this forum and others before posting, and have seen a number of theories from fuel tank breather issues, to what sounds a more likely problem with the injector wiring loom (though seems to intermitent for that and no starting probs ever).

I drive the car every day to work and back approx 30 miles, mostly motorway and this problem occurs perhaps once a week. It also usually happens more than once in quick succession, so say 2-5 judders of a second or less duration over a 5 minute period then all fine again for a week or two.

What I am hoping is that someone can tell me is if there might be any practical diagnostic or visual inspection tests I could perform to try to track this down.

I'm pretty good on petrol engines, but to the wonders of Ruldoph Diesel's child I am a newbie.

I appreciate there are similar issues throughout this and other sites, but they often refer to a misfire, and it isn't like that, its more like the whole thing just shuts down for a second.

Would greatly appreciate any suggestions on what I might examine / lookout for, to try to narrow the possible causes.

The noble gnome

[the_old_diver]

I'll guess that you have already either had the runes read, or your model isn't rune enabled? (No computer link?)

If you get smoke of variable colours during / after the misfire, you might just be in the early stages of having a loose cambelt pulley on the end of your crankshaft, due to a worn or broken keyway. I've had it on both my Sharan AHU and Passat AAZ engines. It seems this problem is not diagnosable via the fault-code reading system. It temporarily throws the fuel pump and valve timing out with respect to the piston position. Temporarily gradually increasing, until it won't go any more.

I'm sure other far more knowledgable members may come along and correct me :-)

[Crasher]

Firstly, have a fault code read done which may come up with a crank speed sensor or needle lift injector error.

The injector wiring loom theory is a red herring, your engine is not a PD so it does not have an injector wiring loom.

[The Noble Gnome]

Thanks chaps, will advise.