Ok so lately the 87 t2 had been bogging out at 4.5rpm at light throttle. If I floored it I had no problem getting past those rpm's and boosting fine. Well yesterday I noticed that for some random reason the boost sensor vacuum line was not connected. I connected the line and what do u know I had no bogging out problem.

Well problem now is that the car feels very rough, it lacks power and although it wont bog out you can feel it kind of jumping at 3k or so. It also feels very rich, it might just be me but man I smell like fumes and my eyes keep on watering while driving. Again if I floor it its fine but I feel there is a miss in power somewhere.

A bit off topic but might actually be related. I ran it at the track a few weeks ago. I ran it twice and never past a 16.5 at 5.5psi (never missed a gear or anything like that). At this moment the boost sensor was not connected cause I remember it bogging out on me on the drive back. Seems very slow right?! Compression is good so thats out of the picture, but there is something going on and I think it all has to do with those damn vacuum lines.

Here are the mods just in case u think 16.5 should have been ok: stock ports, apexi single with 3"dp, rtek 1.7, walbro, 720cc sec, hks filter, ported WG,..think thats it, I didnt raise boost that night since it felt weird at 5.


Thanks in advance guys

 

Do the ONE thing that helped me when I had a issue. Unplug your battery for a whole day. See if it resets the ECU. That's what mine did, and it ran great right after.

 

Its a s4 so no check engine light/ clear code ordeal. Even on a s5 it wont help anything. Disconnecting the battery will have no affect for him.


OP do you have a wideband? Did you actually do a compression test or a poor mans test?

 

I dont have a wideband that's why I don't like picking up my boost. A few months ago a real comp test was done, yesterday's I guess u can say it was a poor mans check.

 

Also I'll try the battery thing I don't think it would work but it can't hurt.

 

Unplugging my battery has helped in MANY cases for me. It helped from everything from a TPS sensor not getting 5V, to my fuel injectors not working, and to the factory alarm. As of right now, my car S5 runs like a champ. haha I hope if helps. Even if it doesnt help, its a good thing to remember. at least to me it is.

 

Tried battery...no luck Alright so can anyone answer me this then..Does the boost sensor make the ECU change mixture?