K first off this might sound stupid but i just found my PCV valve hose just hanging and hitting the fan. The end has a little cracked so im cutting it back and putting it back on. But where?? i have looked for some place where it looks like it should go and even looked up diagrams and still lost. the part connected to the valve cover is connected but i cant find the other part.

Also i did the seafoam trick and its running 10x better. Reason i found the PCV hose lol. but i noticed when i took off my break booster hose the engine smoothed out even more and ran even better. So my question is would it be ok to run with it off??

(pic below of PCV hose)

 

i believe the port is in the back of the intake, thats where it is on my 93. the truck should be running like crap without that thing hooked up. it will have a huge vacuum leak. its possible the previous owner just left it disconnected and plugged the port for it

 

uhh...you sure that hose is for the pcv? My pcv on my 4.3 is on the passenger side. YOu sure the vacuum lines running to the cruise control is hooked up?

 

I was wondering this on my 94 as well, That hose in question runs from the drivers side valve cover to the box where the air filter sits, I am honestly not sure what its for, but I need to get a new rubber hose for mine, as it broke and I did a half A** fix with some heater hose since I did not know the name of the part.

 

Air enters the cylinder heads on the driver's side via the hose that runs from the back of the air filter box to the driver's side valve cover. The air goes across the top of the engine and then vents out the passenger side valve cover through the PCV valve and then into the throttle body via a small tube on the top.

 

Thank you all, for the replies


You might be right cause there is a very similar hose on the passenger side, but much shorter. The cruise control works fine though and it seems like all those lines are attached. This line does pull air but not very much, it is very weak suction.


Now that make way more sense cause there is the exact same fitting on the passenger and drivers side on the valve covers (see #2 pic behind the oil cap its driver side but it is the same on the other side) And I did yank off the Air Box to fix the fuel injection last fall and i didnt put any hose back on, I didnt know there was one.

That might be why it has been really ruff at idle but smoothed out at high RPM. I posted the question a while back why it would be doing that and most said it was a vacuum leak but i couldnt find one. And this hose was dug deep under the fan and radiator so thats why i most likely missed it. But like i said above it feels sort of weak compared to like the brake booster.

 

The hose that's hanging loose behind the air box isn't part of the vacuum system. It's part of the PCV system. Only the passenger side of the PCV system has vacuum. There's really no vacuum on the driver's side. That's a separate system from the vacuum line to the brake booster.

The brake booster vacuum line comes off the rear of the intake manifold right near where the fuel lines enter. There's also a vacuum line coming off the back of the manifold on the right side which goes to the HVAC and 4X4 system. There are a lot of short pieces of vacuum hose on that branch that can get brittle and break/crack. Be sure and check each of those short pieces thoroughly. Also check as many of the long lines as you can. There's one long line that goes to the spherical vacuum tank. There's another one that goes back to the transfer case and then another one from the transfer case to the 4x4 actuator under the battery tray. When I was troubleshooting the 4x4 system on my wife's '93 Jimmy I became very familiar with all of those vacuum hoses.

Good luck!

 

that hose wouldnt cause a vacuum leak. The day i got my blazer forever ago i yanked off the stock air filter set up,and never did anything with the hole. 1st thing i would do is if was in your case. Id drive it down to advance,or autozone etc and pull 1 hose off at a time and buy new hose and replace all of it. Then take it home and remove the throttle body and clean the crap out of the vacuum tunnels etc. The PCv valve tunnel loves getting clogged up. If the pcv doesnt work,it can cause rough idling etc.

Have fun,stay dirty.

 

thanks for the reply
Ah k about the PCV ( and sorry i didnt specify its a AWD Bravada, so no vac lines for 4x4)

Yeah I did replace the that little branch thing that comes off the intake manifold cause it was broken. And of course its impossible to find for a 1994 bravada so i got it off a "W" Blazer from the junkyard. I had to plug the 4X4 line cause the bravada has Smart-track AWD. see swartlkk's posts in links about the no vacuum line from the cases.

https://blazerforum.com/forum/2nd-ge...da-tccm-65606/

https://blazerforum.com/forum/2nd-ge...auto4wd-29995/

 

thanks for the reply

K ill have to do that this weekend, i'm in WV right now and its up in Ohio. i am going to run more Seafoam through the intake too but it might not need it though, might just carb clean everything. For the Vacuum lines though do you or any one which diagram in the link for a 94 bravada?? I know its one with "W" vin but there are still different. (I know AZ isnt the best but the only diagrams i can find)

| Repair Guides | Vacuum Diagrams | Vacuum Diagrams | AutoZone.com