Rough Running On Warm Start

My '98 New Beetle occasionally runs "rough" (if it were a gasser I'd say it was missing on one or two cylinders) on warm starts. When this happens, I shut the engine down and restart. Every time on the second start the engine runs smoothly. I've never had this happen on a cold start. Mileage is just over 174,000.

Any ideas about how to troubleshoot this one?

The car is relatively new to me (about 10,000 miles), so far this has happened maybe four times, all in the last month or so.

FYI, '98 is not an ALH or BEW (not a VE or PD). You would probably be in better hands if you posted your question in the forum appropriate for your engine.

A 98 New Beetle is an ALH, MK IV. A 98 Jetta is an AHU MKIII.

OK, feeling pretty dense here. I've looked at the forum descriptions and I don't see one that seems to fit. Which is the appropriate forum? Thanks.

dlu said:

Thanks. The forum title said New Beetle, I'll move it.

Click to expand...

No, you're in the correct place.

I stand corrected, I apologize.

And you're forgiven

My 98 NB TDI ran rough on cold start up. It was my MAF. Try unplugging the MAF and see if it does it. It will threw a MIL but ignore it or erase it. You too could need a MAF. Hope this helps.

Well, after a bunch of reading and thinking (mostly about hard starts when warm) I started wondering about the condition of my battery / starter -- since the ECU doesn't start delivering fuel until the starter reaches 250 RPM. Didn't have a way to check the RPM (other than the tach and that was hard to read with confidence), so I asked my mechanic to see if they could do it. They found that the starter was drawing 300 A when it cranked. So I started looking at the starter threads. There I found lots of references to odd noises due to the starter hanging in the flywheel. The descriptions of the noises sounds like the noise I was hearing, so I'm off to collect the tools and time to R&R the starter.