I replaced some of my vaccum lines and now it bogs down around 3600rpm. I replaced the pill in the vaccum line to the boost sensor but it still bogs down. what could it be

Might be your secondary's. We had the same problems on a friends car.

would it happen over night??

No probibly not... Not unless there was some bizarre event and the laws of physics were negelcted, nothing I can't think of would do that over night. The car would have had to be sitting or the secondarys never were working and I assume that they were.

yeah everything was working fine. I replaced my pulsation damper and since I was down there I replaced some vaccum lines and now I have that problem.

Only thought might be that the one of the lines might be bad or not connected correctly/snuggly.

Does it just bog down for a second, then kick back in?

no it keeps bogging as the rpms slowly increase

then when I shift it back fires

Sounds like you might have a crossed line from when you replaced them.You might want to take another look and make sure that it isn't the problem.

It backfires when you downshift, that means, the ACV (air control valve) valve and/or the AAV (anti after burn valve) on top of ACV don't function as they should.



check the lines that go to the ACV. Yo ucan check my web page (in sig) for ACV under emissions->secondary air



Since it was working fine before, you must have crossed some vacuum lines.



now, if you ditched the air pump and ACV long time ago, this above is just BS



hugues -

well my air pump is off. but I dont know about the acv.

if you still have the ACV, then the above applies (it's on the passenger side of engine ... you should see 2 open tubes: one to the air pump and one to the air silencer, which you don't have anymore)



the vacuum lines of interest are the 2 just above the ACV: 1 goes to the relief solenoid valve, the other to the switching solenoid valve If those are not connected to where they should, there's trouble. When idling, you should feel vacuum for both of them if you disconnect them at ACV, past 3500 rpms, no vacuum. It's on my web page under emissions->secondary.



hugues -

you could also just check your vacuum routing and compare it with the one in HAYNES manual or factory service manual (www.fc3s.org under how-to's->manuals, fuel and emissions chapter).

or compare it with some one else's car

that might be easier.



hugues -