Hi all, first tech post here, the first of many, I suspect!

Bought an '89 300E for $600 to tinker with (yeah, I know, the cheap ones are usually the more expensive ones, etc., but I was also looking for something with which to get my hands dirty). Has a multitude of issues but I'm going to try to tackle them one at a time. Anyways, I've spent the last two weeks searching and reading on this site and others and I feel I've adequately begun the education process!

The first issue that I'm tackling is a rough idle and severe hesitation upon application of throttle from low rpms. I'm starting to suspect a vacuum leak - the "economy" gauge sits at about 1/2 while idling. I tried to follow the peachparts diy "isolating vacuum leaks on a M103," but when I pull the OVP relay, the engine will not stay running unless I'm applying throttle, so I cannot proceed. Could a severe vacuum leak also cause the car to stall when the OVP is removed?

Thanks,
Mark