NCoppersmith
Member
- :
- Mazdaspeed Protege 3.5
Ok, finished my "build" in that all the parts are installed and the engine starts. As soon as you hit the key she starts right up and pulls a good 20hg of vacuum, which rapidly detoriates to about 10 with the needle pinging back and forth so rapidly you can't actually see it due to motion blur. (Innovate Mechanical G3 Vacuum/Boost gauge directly attached to IM) This is with the 505zoom aluminum intake manifold installed, stock fuel rail and injectors, no EMS. The engine idles incredibly rough with it picking up and almost dying pretty much constantly. It sounds like there's a leak right either at the fuel return regulator or the PCV. I know it's not the PCV, but for the life of me I can't figure out where it is. I have checked and rechecked the entire intake system from the airfilter all the way to the manifold, then traced down every connection. Yes, I've tried using carb cleaner at junction points along the entire manifold, injector tips, you name it, to no effect. (incidently a 10hg leak is one massive leak, to lose that much vacuum I'd have to have a bajillion tiny leaks from the whole system, some of which I'd had to have found and fixed by now)
My scan tool shows the MAF sensor as wildly out of spec (more than double) but swapping it out with my known good P5 MAF gives the same results. It kinda sounds like it might be the fuel return regulator, as that's close to the noise, but I haven't tested that yet. Long Term fuel trim never changes, Short term fuel trim looks like its within normal ranges. For some reason my TPS sensor always shows 10% at idle, the sensor tests correctly, so I wonder if maybe the throttle body is bad/leaking, but I can't tell from where.
Anyone have any direction from replacing manifolds that I might have run into? I could post a video of the engine trying to idle if anyone needs a good dose of depression. :b
My scan tool shows the MAF sensor as wildly out of spec (more than double) but swapping it out with my known good P5 MAF gives the same results. It kinda sounds like it might be the fuel return regulator, as that's close to the noise, but I haven't tested that yet. Long Term fuel trim never changes, Short term fuel trim looks like its within normal ranges. For some reason my TPS sensor always shows 10% at idle, the sensor tests correctly, so I wonder if maybe the throttle body is bad/leaking, but I can't tell from where.
Anyone have any direction from replacing manifolds that I might have run into? I could post a video of the engine trying to idle if anyone needs a good dose of depression. :b