ok guys a while back my fuel pump went out in my 94 blazes with the 4.3 vortec,well i changed that put it all back together it wouldn't crank,well do some searching found out the fpr had went out changed it it would crank but not idle,but some how i wound up pinching the vacum hose that runs to the brack booster and it would idle,well i knew i couldn't keep it pinched so,i took the hose of the pvc valve an put a filter on the pvc valve,an the one that runs up on the intake,my ? is any ideas as to why it won't idle with the hoses connected??please i need help its got me stumped

 

So which hose did you clamp off? The brake booster, the PCV valve, or both? Did you need to clamp off both of them to get it to idle properly?

If you have a bad booster, then it would act as a large vacuum leak. How did your brakes feel when you had the vacuum line to the booster hooked up?

As far as the PCV valve goes, unless you have excessive blow-by on the cylinders, a properly functioning PCV valve should not cause the engine to run poorly.

 

i cut the vacum hose that runs from the pvc valve to the intake,and aded a filter on the end of the hose,n pvc valve,runs ok now but black smoke realy bad when idling,but if i connected it corectly it want run,any suggestions

 

If you have a filter on the valve cover, plug the other hose. It is not necessary.

Be aware that you may fail an inspection if emissions devices such as PCV valves are a requirement in your location.

 

we don't have emission testing here so cool,but i still has a ton of black smoke when you first crank it,n if u let idle for to long,any ideas about what would cause that? it didn't do that until i changed the feul pressure regulator a fuel pump?could it be a o2 sensor?