Vacuum line connection.

[ajciafre]

I replaced my knock sensors on my 1995 Q45 and I cant figure out where the vacuum line that is under the idle air control connects to. Does it Tee into something or is there a connection that cant be seen? I connected a new piece of vacuum line to the connection under the idle air control and left a two foot piece of line dangling. Any help on where it connects to would be greatly appreciated.

[OwnerCS]

Let me try to find and post some pictures. It may be "the vacuum tube to nowhere" connection.

[OwnerCS]

Here's a picture of "the vacuum tube to nowhere" labeled "vac pipe" that is the bottom side of the 3-way hose to the IACV.



In the picture you can see the other side of the 3-way hose to the IACV and the metal line that runs under the plenum.



And a close up.



Here's a slide show of under plenum items.

http://s286.photobucket.com/user/Ridgel ... der?sort=4

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[ajciafre]

you are the man! the line I am referring to is in the last pic. its the small one that comes off the metal tube going into the three way hose. In the pic it shoots off to the left hand side of the pic. I need to know where that line connects. Line to nowhere,lol

[ajciafre]

nice clean motor you have there! :-)

[OwnerCS]

I just went outside to feel of mine to trace down that hose location and I found mine has been cut or disconnected about 4 inches away from the metal connection point. I'm scratching my head on that one unless it was accidentally disconnected when the transmission was replaced about 2 years ago. I can't remember where I hooked it up.

[ajciafre]

hmm and your car is running fine? I looked at the vacuum diagram in the FSM you sent me. Thank you very much for going out to your car to help me out as well. That link is Invaluable! I suppose I should just cap it off and just start the car. I still have to torque all the bolts down yet. another thing I lost a throttle body bolt down in the engine bay. I looked every ware it must be sitting on the frame or some thing but will I be able to run the car with just three or do you think it will pull in air. I'm gonna get a new bolt either way.

[ajciafre]

Oh yea there was no mention of the line in the FSM

[OwnerCS]

This is bugging me as the car seems to be running fine.. The hose seems to have been cut at an angle.. I wouldn't have cut a hose like that in a million years.. I couldn't find a reference to it in the FSM either. I know I knew where it connected when I put the car back together 3 years ago. I need to let the engine cool and get some daylight to trace it down. I hope it is not connected to one of the fuel rail pressure regulators.

[ajciafre]

Well I really do appreciate the help you have given me. If you do figure it out please let me know. Thanks Again!
AJ

[OwnerCS]

Maybe somebody will stop by with an answer.

The question is where does the other side of the vacuum hose within the green circle connect?

[ajciafre]

Yes.

[Q451990]

Boy that's a booger to get to! At least my hamstrings are somewhat stretched now. As best as I can tell, it's going to the fuel pressure damper. Look at the middle drawing of the right column on page EF & EC-6 of the 1991 FSM.

I'm looking with a mirror dangling a flashlight down there, and I lose the hose for just a second as it passes behind the big hose of the "Y" that comes down from the AAC valve, but as best I can tell, that's it.

Heath

[OwnerCS]

Heath - Thanks a MILLION! That sure looks like the hose and connection point. I'm still scratching my head on how the hose got the angle slice (like a piece of Ziti). I may need to get my son with his small hands to reach in to reconnect that one. The car has been running great. It will be interesting to see if it makes a difference. I guess an increase in manifold vacuum opens the damper so excess fuel pressure (from a quick deceleration) can be routed back to the fuel tank?

[ajciafre]

Thank you! luckily I put a 2 ft piece of line on before I put the plenum back on. I'll take a look at the FSM. Hopefully the fuel pressure damper is easy to get to. You guys are great! I dint know there was such a large following for this car. I only paid 600.00 for it over two years ago. the KS has been bad the whole time I had it but dealt with it. I didn't decide to fix it till my number 4 injector went bad. Anyway the lady gave it to me for 600.00 because her mechanic told her it had a bad head gasket. Either he lied to her or she got it confused with valve cover gaskets or she didnt want to pay a large repair bill. Im not sure but thats all it needed besides the knock sensors. I love the car.

[Q451990]

Heath - Thanks a MILLION! That sure looks like the hose and connection point. I'm still scratching my head on how the hose got the angle slice (like a piece of Ziti). I may need to get my son with his small hands to reach in to reconnect that one. The car has been running great. It will be interesting to see if it makes a difference. I guess an increase in manifold vacuum opens the damper so excess fuel pressure (from a quick deceleration) can be routed back to the fuel tank?

According to the FSM it reduces pressure surges in the fuel input. I'm sure the part has some value, or they wouldn't have included it. As much as anything eliminating the vacuum leak will be useful. I'd suspect the transmission replacement as the culprit for the cut hose, it's not far from where the top of the bell housing bolts on.

Thank you! luckily I put a 2 ft piece of line on before I put the plenum back on. I'll take a look at the FSM. Hopefully the fuel pressure damper is easy to get to. You guys are great! I dint know there was such a large following for this car. I only paid 600.00 for it over two years ago. the KS has been bad the whole time I had it but dealt with it. I didn't decide to fix it till my number 4 injector went bad. Anyway the lady gave it to me for 600.00 because her mechanic told her it had a bad head gasket. Either he lied to her or she got it confused with valve cover gaskets or she didnt want to pay a large repair bill. Im not sure but thats all it needed besides the knock sensors. I love the car.

It won't be hard, but with that much hose it shouldn't be bad. Check out that picture I referenced and you'll see where it goes pretty easily. Great story on how you got your car. I'm going to guess valve cover gaskets too. It's also common for the massive "suitcase" muffler to hold moisture and cause steamy exhaust, especially in the fall when it starts getting cool.

Good luck!

Heath

[ajciafre]

Thanks again Heath! I just got her fired up. I have no throttle the pedal is to the floor so Im assuming I hooked something up wrong but shouldn't be an issue. Im gonna go reference the FSM now to find out what im doing wrong.
AJ

[Q451990]

Probably pulled something loose at the throttle body connection or throttle cable cams on the right trying to get back to that hose. fun fun!

[ajciafre]

I figured it out thank you. I had two reversed on the left side. thanks again for the tip about the injector! I will keep you updated. this site is great! I still havent hooked up the hose to the fuel damper. I have torn ligaments in both wrists and cant bend them.
AJ