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caeliat

Vacuum Line Troubles

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Recently I started working on the 626 which has been sitting for the better part of a year. It would rev itself up and down while idling so I took of the TB and cleaned the shit out of it and the IAC valve and fixed that problem. Then it would idle really rough and threw up a P1195 code. I saw this post and my connectors were switched on the boost sensor and fpr solenoids so I switched those back but now it dies unless I keep on the throttle a little. I'm guessing my vacuum lines are all messed up. I looked at the colored diagram stickied on this board and I don't think it has everything (I couldn't find the boost sensor solenoid at least.) 

 

post-30417-0-24304400-1412200967_thumb.j

 

What is this? I looked around but couldn't find it. It has a vacuum line (with sketchy duct tape) that runs into a T with the boost sensor solenoid that you can see in the next picture. 

 

post-30417-0-52286300-1412201021_thumb.j

 

Here's the boost sensor solenoid that's connected to the boost sensor and the T that connects the line from the first picture to the top vacuum port thingy on the intake manifold. 

 

post-30417-0-85361000-1412201045_thumb.j

 

And here's the fpr solenoid that has lines connected to the fuel pressure regulator and the bottom port on the intake manifold. 

 

I have no idea if any of this is hooked up right. Any help is appreciated

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Yep. Those vacuum hoses are messed up. I have my 94 MX6 V6 with me, and I think it should be the same as your 96 626

 

1. See that hose in the lower half of the top picture (that comes up from the cruise control)......and that hose that is sticking up vertically in the lower left corner of the bottom picture? That is supposed to be the same hose. One single hose goes from the cruise control to that vertical metal nipple in the lower left of the bottom picture.

 

2. See that thick hose with a yellow dot on it in the middle picture. There is supposed to be another thick hose right beside it, that runs from the front of the front valve cover, to underneath the throttle body.

 

Can you take another photo from a little further back?

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Cruise control! I didn't know what the hell that was. I'll plug that straight on to the vertical nipple. Do you have any idea where the other line on the boost sensor solenoid goes? 

 

Thanks for the heads up about that second hose, I'll check it out tomorrow morning. And I'll take a picture first thing as well. 

 

Thanks a lot for the reply man. 

 

Edit: I found this picture on the mx6.com forum. It shows the boost sensor and solenoid.

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My 94 doesn't have a boost sensor and solenoid. And my daughter has my 2000 V6, so I can't check that.

 

Your fpr and solenoid is connected correctly in the bottom diagram.

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You have a vacuum diagram under the hood.  Open the hood and look up.  In order to know how to read the diagram you must know exactly what each solenoid is though.

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You have a vacuum diagram under the hood.  Open the hood and look up.  In order to know how to read the diagram you must know exactly what each solenoid is though.

 

I had a hard time making sense of the vacuum diagram under the hood, couldn't find anything in the Haynes manual either.

 

I found where someone had the correct nipple on the IM capped off so I hooked the boost sensor solenoid up correctly. I also have no idea why someone had that vacuum line running from the cruise control duct taped, I cut the line and still had plenty of room to reach. So that's sorted now. 

 

 

Yep. Those vacuum hoses are messed up. I have my 94 MX6 V6 with me, and I think it should be the same as your 96 626

 

1. See that hose in the lower half of the top picture (that comes up from the cruise control)......and that hose that is sticking up vertically in the lower left corner of the bottom picture? That is supposed to be the same hose. One single hose goes from the cruise control to that vertical metal nipple in the lower left of the bottom picture.

 

2. See that thick hose with a yellow dot on it in the middle picture. There is supposed to be another thick hose right beside it, that runs from the front of the front valve cover, to underneath the throttle body.

 

Can you take another photo from a little further back?

 

Here's a picture from further back. I didn't have the boost sensor solenoid hooked up in this picture. 

post-30417-0-62178900-1412185875_thumb.j

 

Could you take a picture of where the second hose is supposed to go?

post-30417-0-62325300-1412186006_thumb.j

Is this it? There's a line under the PCV hose that looks like it's capped off. Where would this line go on the valve cover? Again, thanks a lot guys. 

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Bottom picture: " Is this it? There's a line under the PCV hose that looks like it's capped off. Where would this line go on the valve cover?"

 

Yes, that's it! But it doesn't look capped off to me.

 

On my 94, there's a thick hose that runs from that nipple all the way round to the front of the front valve cover, next to the radiator. It's for crankcase ventilation.

 

But I'm trying to remember...I think they may have deleted that hose in later model years.

 

Sorry I can't take a picture. My daughter showed me how, but now I've forgotten.

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Maybe you thought it's capped off because it's so dirty inside?  That's a lot of black carbon build up inside that port.  That might be a clue that it's time to remove and clean the entire interior of your intake manifold and EGR system. 

 

The EGR boost sensor is basically a MAP sensor.  Think of it as a barometric sensor.  It measures manifold vacuum pressure and can change fuel trim depending if there is a vacuum leak or not.  The 93-95 did not have that which is why vacuum leaks for those years were of vital importance to track down.  The 96/97 introduction of the EGR boost sensor made it so vacuum leaks anywhere after the MAF sensor weren't as critical because the ECU could adjust for them depending on manifold vacuum pressure.  Basically in 96/97 the ECU received a way to compensate for manifold vacuum leaks.  Since it's OBD-II you can look up the PID for the boost sensor and see if it's within spec.  If it's not and is compensating during idle then most likely you have a vacuum leak.  I know that might not help you in your current situation but it's always nice to know what components are and how they work.

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OK. My 2000 626 does not have that second thick hose I was talking about. They must have deleted it sometime after 1994.

 

But I'm still puzzled by that nipple in your last picture (which is where that second hose would normally attach). Maybe check it really is capped off. Plus, the plastic clip in your middle picture, first post, is a double clip, like on my 94, intended for that second hose.

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