when cruising at highway speed the BOV constantly blows-off and stops and repeats about once a second. It starts around 3-4 inches of vacuum and continues up to about 2 psi - which is as far as i"ve went because it starts getting more violent. Although if you give it more throttle it will delay it until your up in to the boost sometimes but once it starts you usually have to let off and start again. I started with a non-adjustable cheap Ebay copy of a HKS sequential type valve, so i installed an adjustable Apexi i had on another project and after i cranked the spring it helped but never fixed it. Anyone have any ideas?

 

where is your boost reference line hooked up at? You still have a maf and does this vent to atmosphere?

Jody

 

boost reference line is on a port in the middle of the intake manifold. I have switched it too speed density - there is no MAF

 

move it to the brake booster vac line. comeing from you brake booster to the back of the motor!

 

Ok i moved it to the brake booster line and i think it helped a bit, but never fixed it. When you get it into boost it is good till it shifts or you let off a bit then once it blows off once it repeatedly blows off till you let off fully and start over again. Could the BOV be too small or anything? It worked fine before but that was on a stock 305 tpi that was moving a lot less air.