Hello,

I'm helping my brother-in-law trouble shoot his rough idle on his 1990 240 DL wagon. The idle will smooth out as you give it throttle. We pulled the trouble codes for the ECU which are 2-3-2 and 1-2-1. We had a 1-4-2 for the EZX but it had cleared after resetting. I've also noticed that there's a hiss which sounds like a vacuum leak to me. I've inspected most of the lines topside and they look acceptable. I'm wonder if this is a natural sound for this engine, or should I consider looking deeper for a leak?

Anyways, I'm hoping to get information that will put me in the right direction to get his wagon repaired.

Thank you,

Jeff

 

Obviously you have a vacuum leak, it will explain things, so look for it, and no, these engines don't sound like that normally...