Once i get to about 6600 rpm, the engine stops accelerating, kinda bogs down... it didnt use to do this, whats the deal? Thinking it was a clogged fuel filter i replaced that, but to no avail... other possible causes?

this is an 86 sport na, with working 6 ports


~Jesse

 

Have you advanced your timing? Or replaced the vacuum hose to the boost sensor without replacing the bead? Those were two problems I had with the same hesitation. I pulled the bead from the stock hose and put that in my new silicone hose. And set my timing on the marks.

Hope that helps.
Brian

 

Does it happen only at 6600?

 

I get the same sort of thing, but sometimes it'll go away when the car is really warmed up. Like after doing 5 or 6 0 - 100 mph runs.

 

Do you still have stock cats? They might be clogged. Check your timing too.

 

I have no cats at all.

Timing is advanced, maybe 10-15 degrees(1/4" on CAS), could that be it?

 

As far as I know, my timing is dead where it should be, haven't messed with it and mazda said it was good. As it happens, mazda also replaced the vacuum line going to the boost sensor... so im guessing whatver bead thing was in there is long gone now, what did it look like, where can i get a new one? My cats are brand new, bonez highflow.

 

anyone know what this bead thing looks like, or have a pic?


thanks,

Jesse

 

Couldnt see any bead type thing in the vacuum line, but when i tried blowing through it, air went through a little one way, and hardly at al the other.. Is caused by the bead?


~Jesse

 

Bead is just a plastic "ball" with a hole in it. Affected my high end rpms when I didn't put it in my new silicone hose. Found it in my stock hose.