Engine missing at low RPM

1999 VR6 Tiptronic Passat stutters or misses at RPM's which are less than about 1600 RPM. Can notice at takeoff, but most noticable when cruising at say 40 MPH up slight grade in 5th gear.
Ran tank of injector cleaner without results; diagnosed as intermittant no electrical at cylinders 2 and 4 so had new coil pack installed without results. Plugs are new. 37,000 miles in vehicle
Any ideas before I spend another $400 for a non-fix.
Closest VW dealer is 90 miles so I've been trying a local shop in Grand Junction.

Thanks

Hey, mine is doing something very similar. My VW guy said it might be the ignition module or the coil package. Good luck.

There Is No Vr6s In The Passat In 1999 The Last Year To Get That Engine In A Passat Was 97. You Have A 1.8 L Four Cylinder Or A 2.8 L. V6. Which One Is It?

I have the 1.8L, are you saying they didn't make them with turbos?

What Bleed is saying is officially the pre '99 Passats had the AAA coded engines known as VR6, but in '99 they made a design change to the AHA coded engines & call them just V6's. Regardless, you've got a 1.8 litre turbo engine (AEB code if it's a '99).

P.S. Also offically it's not an ignition module, the correct technical term is ignition power output stage.

no boschman the vr6 went away from the passats in 97 the 98 passats were a new body style and the only two engine options that year was a 1.8l turbo engine or the 2.8 l v6 not vr6

I have a 98 1.8L turbo. I ordered the ignition module or the igition power output stage. It said it was for the AEB engine, which was for a 98 and up. I don't know what is right, but I hope it fixes the problem. And thank you guys for your help.

I don't know if this is the same problem you are having, but my 99 Passat V6 idles rough but runs fiine otherwise at high rpm. I haven't been able to fix it.

It's got new spark plugs and plug wires. Check engine light is not on and the mechanic couldn't see any error codes with the scanner.

If it needs a new coil packs or iginition module, wouldn't the scanner see any error codes?

Mine sounds similar to that. Can you notice a lack of power is the car?

I would think the scanner would pick up an error in the coil packs or ignition module, but I'm not a mechanic.

Have you replaced the timming belt? Mine was idleing really badly and I needed a new timming belt. But you couldn't drive it very long if it needed a new timming belt.

I bought the car used and it has 76k miles on it. I don't think the original timing belt has been replaced. BTW, when should I replace the timing belt?

There is no lack of power on mine, just the rough idling. I already tried several bottles of fuel injectors cleaner. No luck. But it also seems to be temperature related, when the air temperature is hotter, it idles worse.

I thought you could go about 100K miles without replacing the timing belt, but mine has 73k on it and I just replaced it.
I tried fuel injector cleaner, it didn't help either. But my temperature isn't changing, it's runing normal. It sounds like yours is missing. I have noticed a lot of problems with the #2 cylinder. Your problem may be in the coil pack for that cyliner.

The engine temperature actually doesn't change. What I meant was the outside air temperature seems to affect the rough idling. The hotter the outside air temperature is, the worse it gets.

Is there a way to check the coil pack? The mechanic told me there wasn't anything wrong that he could tell since the scanner didn't pickup anything.

I think you can check the coil packs, but you have to have a particular guage. I don't remember the name of it, but someone else might.
I don't know why the temp. outside would effect the idling. That is pretty strange.
All the other things seem to point at the ignition module, or the ignition power output stage.

I found out. You can test the ignition module (ICM) with a digital voltometer. This may help answer more questions. If the link doesn't work, go to the forum about the location of an ignition module on a 98 vw passat 1.8T. Good luck
http://www.clubb5.com/forums/viewtopic.php?t=66779&sid=c472f1f8291573bb0ead8e2f449ec911

Here is the message that has just been posted:
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ICM (ignition control module) also known as the power output stage and other aliases (ICM is most common name) failure is a very common problem with the 98 - 99 AEB 1.8T engines. Here is an excellent link on how to test and replace a bad ICM:

http://www.clubb5.com/forums/viewtopic.php?t=66779&sid=c472f1f8291573bb0ead8e2f449ec911

Thanks for the info. My engine is the 2.8L V6. Would you happen to know if the ICM and the coil packs are similar like the 1.8T?

The V6 motor does not have an ICM similar to the AEB 1.8T motor. However, it does have three coil packs, one for every two cylinders. So, if a coil pack on a V6 goes bad then you will have misfires on two cylinders.

I would think so, but, I looked at the website I bought my ICM at (www.ecstuning.com), and I didn't see any coil packs or an ICM for a V6 passat. I can't understand why. I would think they are the same, and that particular site just may not carry them. But I really don't know for sure, sorry.

harthouse, that makes sence. I guess that's why that site doesn't carry the same ICM for a V6.