Need vacum diagram 1999 Blazer
 

I'm almost done with my project. I need the vacuum diagram to get that out of the way. It looks like I have one vac hose with no home. Learned not to break stuff like the map sensor and the oil pressure switch $80 there.

Search the forum with the search button. Search for vacuum diagram. It has been posted many times.

How about a link instead of a generic search?
 

I am new here too. After using your search info I was presented with a plethora of things totally unrelated to what I was searching for. Do you have an actual link to where this "posted many times" posting is? I have a "vacuum basket case " I just bought that had most of the lines simply missing or cut off and plugged. It would not even start. This is a 99 4wd blazer with a 4.3 in it.

I have been searching for hours and cannot seem to find the post you are referring to. An actual link for this post would be most welcome by myself and probably others here as well.

Thanks!

i found it before for another thread and i agree about the search system in this style of forum - lacks the ability to search out with " " around what ur looking for to get JUST that phrase.

https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/95-blazer-s10-vacumn-diagram-37998/

The search function works very well once you understand how to use it... :icon_wink:

Thanks for the link. It helps a lot. I don't suppose either you or anyone else out there may have a complete engine vacuum hose routing diagram? These things appear to be like a bowl of spaghetti with all the hoses. I have found bits and pieces here and there, but with mine being mostly chopped up and capped off, it is impossible to say what I am really even looking for to make sure I get everything correct.

There really isn't much to it. The only other lines that run off of the intake are for the PCV system, brake booster, and then from the EVAP purge solenoid over near the coil. The vacuum line for the HVAC & 4wd attaches to the same fitting as the PCV tube and runs up near the booster where there will be a check valve and some t's. From the check valve, the line will branch off to go into the firewall (HVAC), to the transfer case (4wd), and to the vacuum reservoir located in the driver side fender.

As far as I know, there is no vacuum reservoir inside the fender. There is one on the underside of the hood that looks like a ball that has only one connection on it I scavenged from a junkyard. Will that work in the absence of the one inside the fender?

Also, there is some kind of tee coming out of the intake on the driver's side of the intake just behind the throttle body. One side of this tee connects a hose to the PCV valve, and the other side of the tee is broken off smooth at the junction. Someone jammed a regular tee into this opening but it does not seal, so there is a huge vacuum leak. This side of the "jamed in" tee has 2 cut hoses on it that are plugged. There is no way to plug the broken side of the "intake tee" except with some kind of sealer. I hate do that because I don't know where the "intake tee" is supposed to connect, and I don't know if the "jammed in" tee is really supposed to be a tee or just a straight hose to somewhere. This connection does not seem to be in your description above. Do you know where it goes?

I do not see an EVAP purge solenoid on the intake. If I get one, where does it connect?

There are also 2 tiny hard lines going through the firewall. One of them goes through the same hole as the fuseblock. I "assume" this one needs direct manifold vacuum for the heater controls? Which direct manifold vacuum source should it use?

See what I mean about a vacuum line basket case?

In addition, I don't know where the rear washer fluid hose is supposed to be connected. The front one is self-evident in its placement.

Concerning the vacuum reservoir, look again. It is actually INSIDE the fender with only a flat plastic surface visible. If you pulled a hood mounted unit off of an older vehicle, it will perform the same function provided it is sealed and you have a place for it to securely mount & fit.

There is only one small vacuum port and that is located on the same fitting that the PCV valve connects to. If your small nipple is broken off of this fitting, you will either have to replace the fitting, or make proper repairs to your current fitting (epoxy, etc). If you do not know how to make the proper repairs, you likely will just want to replace the fitting. It twists off of the lower intake manifold after pressing in on two tabs if I remember correctly. The very next item in the line needs to be a check valve. This keeps vacuum pressure in the vacuum system so the accessories can function properly while the engine is not producing a lot of vacuum (wide open throttle and/or heavy engine load).

As far as where the vacuum hose goes through the firewall, you will have search for that information or wait for someone else to respond. I have never gone looking for it. Don't get the hood release cable confused with a vacuum line though. :icon_wink:

Concerning the EVAP system, I'm not sure I would worry your head about that. If you do not have a check engine light stating otherwise, you likely have a properly installed and functioning EVAP system.

For a view of a lot of the components on an SCFI engine (96+), take a look at the fuel pressure test thread which can be found in the Tech Article (DIY) Index link in my signature. Also found using the search feature is this handy view which applies to the 98+ NV233 (NP1) equiped vehicles:
https://blazerforum.com/forum/attach...1&d=1266732332

Much of this information is out there it just might take a little of your time to find it. Suffice to say that if I say its out there, I likely typed it out at some point or another and that you should be able to find it. Once you figure out how to use the search feature, a lot of your answers will be easily found.