Best MBC for 2004 S40 1.9T?

FixXxer6 · Post by **FixXxer6** » 02 Oct 2013, 10:45

What would be the best MBC for a 2004 S40 1.9T? I'm not trying to go crazy with the boost without a tune. I just want a little extra. Also, if anyone else has a MBC on this type/year of car, what is your's set at and what experiences have you had with it?

Post by **matthew1** » 02 Oct 2013, 10:59

I put a MBC on my 1997 850 T5, and it's a dead-simple mechanical valve.

Here's more: https://www.matthewsvolvosite.com/forums ... =5&t=11494

Here's a post from an S40 T4 owner: https://www.matthewsvolvosite.com/forums ... 13#p230713

FixXxer6 · Post by **FixXxer6** » 02 Oct 2013, 18:42

Okay. I built a MBC today. It looks home made but it looks good. It definitely works well. I connected the lines directly to it and left the TCV plugged in and out of the way. I made a run at about 11 psi and the car started to studder slightly. Then the CEL flashed about five times like a misfire code. I decreased the boost a few more times on a few more runs until I got down to 6 psi. The car still studders just a little bit but the CEL didn't come back on. What am I doing wrong?

FixXxer6 · Post by **FixXxer6** » 04 Oct 2013, 11:16

With the boost controller set at 7 psi, I still get a slight engine stumble at around 3,500-4,000 rpm. The CEL blinks as if there is a misfire. Well, I bit the bullet this morning and ran the car hard until the CEL stayed on. I went and had the code read and, of course, misfire. P0304 code. Cylinder 4 misfire. I bought a new wire set and 4 new plugs and checked the plug gap before I left the store (.028). I replaced both coil packs last month so they should be ok. I'm going to replace the plugs and wires this afternoon.

FixXxer6 · Post by **FixXxer6** » 04 Oct 2013, 17:25

SOLVED! The #1 cylinder had a bad wire and both #1 & #2 had bad plugs. The #4 coil and plug both looked fine but I changed all plugs and the two wires. I'm running 14 psi and it's pulling hard and is smooth as glass. Nice!