Idle kpa around 50, what could be the problem?

DGruber58 · Post by **DGruber58** » Fri Jun 09, 2006 7:59 am

I have a 2.0L 16v VW Jetta. Right now, it idles around 50kpa. I would think vacuum leak, but when driving, and I let off the gas, it can drop to 15-20kpa. Any ideas what might be wrong? I need to get this sorted, then I can start fine tuning the rest. (warmups and ase are really bad right now).
Any help would be greatly appreciated.

rs2000 · Post by **rs2000** » Fri Jun 09, 2006 8:01 am

Sounds normal to me, thats how i'd expect it to be.

keithmac · Post by **keithmac** » Fri Jun 09, 2006 9:25 am

That`s good, my cammed 16v is 65kpa at idle! You`ll always get lower MAP on overrun (mine`s in the 30 region).

DGruber58 · Post by **DGruber58** » Fri Jun 09, 2006 4:49 pm

My engine has stock cams, and other people running MS on their VWs idle around 35-45. Just seems like something is off.

Bernard Fife · Post by **Bernard Fife** » Fri Jun 09, 2006 5:15 pm

DGruber58,

The most common causes of high idle MAP are timing, tuning and vacuum leaks (a plugged exhaust, cam timing off, poor compression, leaking valves, and a malfunctioning PCV valve can also do this). Keep working on the tuning, people often find they can lower the idle kPa 10 or even 15 kPa as they narrow in on the optimal tune. The procedures are in the manual.

Lance.