Vacuum leak

I'm not sure what the issue here is, if there is one with it, but it seems like it shouldn't be this way...

My wife's '94 SE has been getting progressively worse gas mileage... I started checking things under the hood today, and as it turns out, the hose that runs to the PCV valve in the front valve cover, also has a sort of "T" fitting in it, that plugs into the manifold, right behind the TB flange... it's loose there.

Literally, so loose that touching it causes the engine to rev up to about 3k... it won't rev any higher, since the hole doesn't let enough air in...

She's been complaining about loss of power at random intervals, and overall loss of low-end torque... I'm assuming this has something to do with it...

Just wanted some confirmation on this, basically... and maybe the name of that hose, or if there is a grommet in there I need to replace, etc...

Honestly, it looks like it was glued in place by the last owner, which I wouldn't doubt, as he also wired the fans to the ignition circuit instead of replacing the thermal switch.

Not that it really makes a difference, but I pulled the PCV valve out, just to make sure it was the same line, while the engine was running, and the same effect... 3k rev and steady hold, no skipping, no popping, etc...

Also, would a vacuum leak cause a CEL? It's been coming on intermittently since we bought the car, never really checked the codes... I'm trying to find someone w/ a OBD1 scanner, so I can check them, but in the mean time, I was also wondering if this could be causing it.

Help is appreciated.

sounds like an issue. There is also one that hooks up the the intake duct that goes to the back valve cover under the coil packs. This one sometimes comes loose and allows a vacuum leak also. Maybe worth checking

Wish I knew the part number number for you.... I'm sure Rich will know. You can probably just take it off and bring it to the dealer. It cant be to expensive.

I'll keep my eyes open, if I come across one from a junked 3100, I'll snag the pcv hose for you.

BTW, there is no grommit, its all one piece. The rubber probably just dried up and isnt sealing good enough anymore.

And yes, your cel on sometimes and then goes off on its own sounds like a fuel trim problem. Next time it turns on, get a paperclip and jumper the two upper right terminals of the alda. Then turn the key on but not start and count the SES light flaskes. It should be like this.... flash flash flash pause flash flash will be code 32.

I actually just found the part... it's $2.

There is a grommet in the intake, that sometimes "dry-rots, and will get sucked into the intake manifold, eventually disintegrating and being put through the engine."

The hose itself is fine, I pressure tested it to 10 psi. (Cork one end, put pressure on the other.)

I will also check on that rear hose, I think I know which one you're talking about, I'm pretty sure I was wiggling it around a bit, trying to find out where I heard the leak from.

My vacuum leak test consists of a can of ether or carb cleaner... spray it everywhere there could be a leak, and the engine will either die out a bit or rev up if there is a leak somewhere.

Anyway, I'm going to get that part tomorrow, and replace it, so the hose will seal properly, and hopefully, that will help with the gas mileage... we started out getting 26mpg, and 3 weeks later, we just filled up today, it's 19.5... pretty sure it will keep getting worse until something is done about it.

Anyway, I'll let you know what happens after that grommet, although the effects won't be immediately obvious (gas mileage). Should help with power though, so we'll see.

Oh... as far as checking the SES light myself, the car has no "B" terminal in the datalink connector... so I can't just jumper it to check... three diff manuals confirm that many OBD-1 GM's didn't allow the self-diagnosis feature. (I suppose so that you'd have to take it to the dealer, back then... but I can get a $20 scan tool to check it out, which I probably will buy tomorrow as well.)

Yes, I ran across the same problem with the ALDL connector on a 1994 buick. Better be carefull with those cheapo scan tools. I have one from wally world for OBD1 gm vehicles, but its the same deal, there is no B terminal, so the POS didnt work on the buick.

News to me about the grommit. Is your motor a 3100sfi or 3.1mpfi? Could have swore on the 3100 the rubber grommit was one unit with the PCV hose. My Bad! Sorry.

Glad you found the replacement part at a good cost. Lets just hope this one doesnt get consumed by the motor. Because I'll bet its not good to send chunks through. (have a story..... Bolt on top of a piston once.... Not Good)

Good Luck!

lol, it's just rubber, by the time it falls in, it's been disintegrated anyway, according to OEM's.

Anyway, I believe it's a 3.1MFI, since the 3100 apparently is way different, and the crank won't even work for this (diff angle on the motor or something... what was GM thinking???)

BTW, how hard would it be to put a 3.8 w/ tranny in her car? just the bolting it in part... the wiring and such, I can take care of... but I can get an SSE motor for $500 w/ tranny, ECU, axles, and harness... I'd like to see if I could put it in there for her after I get her another car to drive.

Supercharged '94 4 door FTW!

It would be a nightmare..... Even ask Jae. (a forum member that recently did that exact swap) He even has pictures, and I believe finally got all the bugs worked out. Do a search of the forum.

will do, but that's years down the road... wonder if it would be easier to swap in the 3.4 and add external engine management and a custom lower manifold w/ the M90 bolted on it?

I'm thinking that would be easier than playing with mounts and such.

Oh... put that PCV valve grommet in, and apparently, it's a 3100... that's what's on the engine anyway... 3100 SFI I think.

Obviously, that vacuum leak wasn't the problem... the check engine light still comes on after driving for awhile... getting a scanner tomorrow from a friend for a few mins to check the codes, see what's up.

Might be trading the car for a '96 GP 2 door... same engine and such, just a lil newer, red, and 2-door, w/ the headlights that wifey likes... the ones that have the plastic front end, with the headlights sunk back in a bit... they look like "evil eyes" she says.

Anyway, it has bucket seats front and back, which is really what she wants... and a floor-mounted shifter.