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kewlpop 01-28-2015 03:42 PM

HELP! high idle 1995 Saturn SL -- Vacuum Problem?
[sorry i was not allowed to post a photo link to url. i will try to upload photo to my pics]


While driving to work this morning my car, manual 5 speed, starting running rough, the engine light momentarily came on and it finally developed a very high idleÖup to 3,000 -4,000.

After arriving at work, I popped the hood in the parking lot and noticed on top of the intake manifold / throttle body there is this piece of plastic housing (see photo) that has a small hose/tube and a larger tube going into it from underneath the manifold.

Now, I also noticed the little tube had come out. Actually what I discovered is that it broke off inside the plastic housing.

So while trying to work out the remaining little hose from the Ďhousingí (I do not know the technical term for this piece) with a tiny screwdriver wedged up in there and turning, the larger hose broke! Ugh! Honestly I assumed it was molded into the housing as a one piece unit. Dunderhead!

Anyway long story short, I was able to get the remaining larger hose out of the housing, but wasnít sure I got the remaining little hose that had broken off.

I put the thing up to my mouth and played it like a harmonica and I could fell the air coming out cleanly on the other side through the larger tube opening, but I could not feel any pressure coming out from the smaller tube opening. I assume that this is supposed to be clear and allow air flowing through. Iím guessing I didnít get the smaller tube broken pieces all out, or maybe I did, and the opening is just so small that any air flow was unnoticeable?

So, can I buy this housing piece (whatever itís called) at the local auto parts store? And also, these tubes seemed incredibly dry rotted. Were they actual rubber hoses at one point, or are they some type of plastic? They are very rigid. I know itís cold outside, but I donít think any amount of heat is going to make them more pliable.

Next question. Assumedly I can replace the two hoses, but where do they go from the top of the throttle body?

I have managed to get both hoses back in the housing, but something is still definitely not right. Idle is now down to 2,000, but, yeahÖ

Within the last year I have cleaned the throttle body, within the past few years, I cleaned the EGR, the ect has been replaced a few years back. I replaced the IAC valve, but have not replaced the throttle body positioning sensor. But Iím guessing my problem as it stands is quite obvious. Get those hoses back in and properly seated! Once I do this, and the car still runs idle high, then Iíll proceed to the next troubleshooting step.

Thanks for any help!

Chub 01-28-2015 04:31 PM

Re: HELP! high idle 1995 Saturn SL -- Vacuum Problem?
What is broken are the two plastic vacuum lines, one of which is important. The smaller line goes to the fuel pressure regulator and if this has a vacuum leak it will impact fuel pressure and can cause the car run badly. If I remember correctly, the bigger vacuum line goes to the back of the motor to a switch for the fuel evap system. A leak in the evap system won't give you any rough running issues but a crack in the smaller line will cause the fuel pressure to be wrong. The best fix is to get these lines from a junkyard as I doubt the parts stores will have one. If you still have a decent-sized piece of the smaller tube you could always JB weld it in place in the housing on the throttle body to seal the leak. I am sorry but I don't know if these vacuum lines actually have a specific name. I tried finding one on Rock Auto but I didn't see any. Best of luck in fixing your engine.

Also, I had the same problem happen on my car a few years ago. These plastic parts just get brittle but I was able to find one that had little damage at the junkyard.

kewlpop 01-30-2015 11:22 AM

Re: HELP! high idle 1995 Saturn SL -- Vacuum Problem?
UPDATE: after wedging both vacuum hoses in the housing as tightly as could, the drive home wasn't so bad. still had a high rolling idle relative to what it was before (around 1,750). and on every shift the rpms revved to around 3,000. sitting idle was acceptable at 850. but i could tell something still not right. it took 3 seconds for the idle to drop, whereas before it was immediate.

but, here's the twist. i left my headlights on all day yesterday and drained the battery. i had to get 'jack rabbit' roadside to jump me. thx usaa tow insurance! props to jack rabbit for coming quickly. btw, i really don't like those side terminals on the battery. not a lot of post to grab with the cables. i was unsuccessful when i coworker tried to jump me with cables.

so i'm guessing that with the battery being completely dead, it may have 'reset' the pcm? just a guess, because the car ran flawlessly on the way to work this moring. i mean beautifully.

another miracle in the wonderful world of saturnland.

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