split-second stalling of ALH engine

Hello,

I have a 2003 ALH engine, and sometimes when idling it will stall for a split second, but after skipping a beat will pick up where it left off. What might be causing this? And when cruising the tachometer will dip occassionally by about 100 rpm.

miltoncf said:

Hello,

I have a 2003 ALH engine, and sometimes when idling it will stall for a split second, but after skipping a beat will pick up where it left off. What might be causing this? And when cruising the tachometer will dip occassionally by about 100 rpm.

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Have you changed relay 109? The original ones were subject to failures and sometimes they were intermittent.

Dave

miltoncf said:

Hello,

I have a 2003 ALH engine, and sometimes when idling it will stall for a split second, but after skipping a beat will pick up where it left off. What might be causing this? And when cruising the tachometer will dip occassionally by about 100 rpm.

Click to expand...

Dirty Injectors?

Relay 109 is a great thought, although I'd expect it to intermittent all the time, not just at idle. Well worth checking out, though.

Another possibility for a random skip might be a crank position sensor on its way out... or the wiring therein. Again, would expect this to be a problem throughout the range as opposed to just at idle.

So of all the suggestions, a wiring problem looks likely, esp. as rabbits had made a nest in the lining under the hood, and chewed out a hole in order to slip in-between.

Damn! Rabbits taking up residence is a new one to me! I've seen loads of mouse damage!

Does the CEL come on when the engine is acting up?

Mine has this same issue but it only seems to do it when it's cold on my 2003 tdi

AndyBees said:

Damn! Rabbits taking up residence is a new one to me! I've seen loads of mouse damage!

Does the CEL come on when the engine is acting up?

Click to expand...

The stalling is too quick & infrequent to trigger a light; nor do the
temporary dips despite being less quick & more frequent.

The insulation has a bigger hole than the biggest kangaroo rat would need, and I've seen desert hares jump up into the engine compartments of other cars on cold days.

Can you pleas keep us updated about the solution?
I also seem to have a similar issue, both on idling and an occasional "hiccup" when speeding up, non of them is constant and sometimes it doesn't happen at all, no warning lights or codes.
Thought it to be air in the fuel system but not sure any more.

Had a similar issue with my 96 Passat wagon. Engine would skip a beat, tach would drop, then engine would go right back to normal running speed. Slowly got worse over time. Cause was a bad ignition switch. My wagon is now on it's third ignition switch.