M103 R&R, now low idle?

[John5788]

I just finished a little project on my 1993 190E 2.6 where I replaced the head gasket, cleaned out the intake components, replaced the timing chain rails.

The car started up on the first attempt of firing it up this afternoon and runs great under throttle, but I am having severe issues at idle.

at idle, the RPM drops to around 500 rpm when I coast to a stop and put the car in neutral. at this point, the vacuum is very low and the oil pressure is very low.

I will investigate tomorrow by checking compression, OVP, and IACV, but i just find it strange since my motor was idling just fine before the job.

any ideas? any specific tests i should run?