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What is this hose? by rice.1
Started on: 08-18-2014 07:02 PM
Replies: 12 (593 views)
Last post by: Patrick on 09-02-2014 11:33 PM
rice.1
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Report this Post08-18-2014 07:02 PM Click Here to See the Profile for rice.1Click Here to Email rice.1Send a Private Message to rice.1Edit/Delete MessageReply w/QuoteDirect Link to This Post
And could it be the cause of my high idle issue?



I cannot seem to find the reason for my high idle. I've replaced the vacuum lines, the EGR tube, made sure the pipe was seated fully in my intake tube. Still idling around 2k. I found that hose disconnected, but even when I held my thumb over the end of it, nothing changed. It's driving me nuts! Any advice on what to look for next?
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Report this Post08-18-2014 07:40 PM Click Here to See the Profile for cyrus88Send a Private Message to cyrus88Edit/Delete MessageReply w/QuoteDirect Link to This Post
Is that not your brake booster vac hose?
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Patrick
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Report this Post08-18-2014 07:45 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
...or is it connected to the non-used PCV tube on the firewall? If so, it should be plugged to prevent air from being sucked into the clean side of the air filter canister.

EDIT: I assume the recall has been done on the PCV system? Show us a picture of the large rubber elbow/tube between the TB and air filter canister.

[This message has been edited by Patrick (edited 08-18-2014).]

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85 SE VIN 9
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Report this Post08-18-2014 07:47 PM Click Here to See the Profile for 85 SE VIN 9Click Here to Email 85 SE VIN 9Send a Private Message to 85 SE VIN 9Edit/Delete MessageReply w/QuoteDirect Link to This Post
That looks like part of your crankcase ventilation system. It should be connected to your snorkel just in front of the throttle body. Is it connected to the rear valve cover? It should be a pipe, but maybe somebody lost that.

Most likely the cause of your high idle is the idle control valve. It's a little stepper motor that drives a pintle that - oh, well that's about as far as my knowledge goes. It does cost around forty bucks and requires a very large socket to get it out of the side of the throttle body.

It usually throws a code 35. Do you know how to check for codes? You remove the little panel that covers the lighter socket and short out two of the pins in the primitive diagnostic connector. When you turn the ignition on with these pins shorted the service engine light will flash a sort of morse code.

When replacing the IAC be very careful how you adjust the pintle. See the instructions that come with it. You can get the part from the Fierostore.com, rochauto.com, and numerous other online sources.

You can try removing and cleaning the part and the little tube it operates in. Use throttle body cleaner (like carb cleaner, but without silicone, which damages O2 sensors), but don't get it in the IAC itself. I did this to mine because it would sometimes idle high. After that it always did.

Also, you have to drive over 35 mph before the IAC will work for the first time.
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rice.1
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Report this Post08-18-2014 08:31 PM Click Here to See the Profile for rice.1Click Here to Email rice.1Send a Private Message to rice.1Edit/Delete MessageReply w/QuoteDirect Link to This Post
I'm not sure if that's the brake booster vac hose or not.

I believe the recall has been done if that's what the tube is that goes into the intake tube coming from the rear valve cover. I've read somewhere on here that that is sometimes the issue, the tube not being fully seated into the intake tube. But I made sure it was seated properly.

The hose is to the left of another hose that plugs into a line running to the right side of the upper intake plenum. The hose that's disconnected seems to run along the firewall and, I believe, goes into the firewall next to the air canister. I'm not recalling the exact specifics, so if that sounds off, I'll take a closer look tomorrow. I've never noticed anything being plugged into that hose to prevent air being sucked in before, and it never idled high before, so not sure that's the issue.

I have read how to get the codes, but I haven't done it yet. If it throws a 35, is that 3 quick flashes, followed by 5 long flashes?

Just a little history with what I've done so far with this issue. When I replaced the valve cover gaskets, and went to put everything back in, I started having the high idle. I thought I had maybe missed a line, so I took everything back apart, but couldn't find anything disconnected. I found some boots that were a little rotted, and a couple lines that had very small cracks, so I replaced all the lines with SS. Still didn't fix it. I replaced the EGR tube with Rodney's. The old tube was pretty clogged, but still didn't fix the issue.
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Report this Post08-18-2014 09:07 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by rice.1:
I'm not sure if that's the brake booster vac hose or not.


It's not... you can see the brake booster hose connected properly just above and to the right of the one you're holding in your photo.

 
quote
Originally posted by rice.1:
I have read how to get the codes, but I haven't done it yet. If it throws a 35, is that 3 quick flashes, followed by 5 long flashes?


Yes, except that it will play code 12 three times first, then any stored codes three times each, followed by code 12 three final times to let you know it's finished.

Another source for the vacuum leak could be the cruise control vacuum canister... the thing that looks like a juice can near the driver's strut tower. They usually rust out from the hidden bottom side.
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rice.1
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Report this Post08-18-2014 09:37 PM Click Here to See the Profile for rice.1Click Here to Email rice.1Send a Private Message to rice.1Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Bloozberry:


Yes, except that it will play code 12 three times first, then any stored codes three times each, followed by code 12 three final times to let you know it's finished.

Another source for the vacuum leak could be the cruise control vacuum canister... the thing that looks like a juice can near the driver's strut tower. They usually rust out from the hidden bottom side.


Is there anyway to test this, or just feel the bottom and see what kind of shape it is in? I don't see a code for it listed in the ECM codes.
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Report this Post08-18-2014 09:51 PM Click Here to See the Profile for fierosoundClick Here to visit fierosound's HomePageClick Here to Email fierosoundSend a Private Message to fierosoundEdit/Delete MessageReply w/QuoteDirect Link to This Post
That line should have be plugged off when the dealer did the recall work.
See here: http://www.fiero.nl/forum/Forum9/HTML/000032.html

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[This message has been edited by fierosound (edited 08-18-2014).]

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Report this Post08-18-2014 10:37 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by rice.1:
Is there anyway to test this, or just feel the bottom and see what kind of shape it is in? I don't see a code for it listed in the ECM codes.


There are no specific codes for a malfunction in the cruise control, but if the engine is running too lean because of a vacuum leak it will throw a code 44, and code 35 if the idle speed is faster than 975 RPM for more than 45 seconds.

To rule out the cruise system, you can isolate the vacuum canister by locating the two steel vacuum lines that run along the rear firewall towards the driver's strut tower. On the upper line you'll see a little tee (again, next the LH tower) with a rubber hose connecting the tee to the cruise system. Try unplugging the hose at the tee and blocking off the metal nipple on the hard line with some electrical tape or something equivalent. Start the car and if it still idles too fast then that wasn't the problem.
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RJS525
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Report this Post08-19-2014 06:41 AM Click Here to See the Profile for RJS525Click Here to visit RJS525's HomePageClick Here to Email RJS525Send a Private Message to RJS525Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
If so, it should be plugged to prevent air from being sucked into the clean side of the air filter canister.


 
quote
That line should have be plugged off when the dealer did the recall work.


It was recently pointed out to me at a recent club show that this hose on my car was not plugged.

Excuse me for asking a dumb question, but what is the proper way to plug it and/or the easiest way to effectively plug this hose so that it doesn't suck air into the clean side?
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rice.1
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Report this Post08-29-2014 04:33 PM Click Here to See the Profile for rice.1Click Here to Email rice.1Send a Private Message to rice.1Edit/Delete MessageReply w/QuoteDirect Link to This Post
Had a few minutes today to check the codes. I was expecting code 35 for the IAC, instead, I got code 21, TPS (high voltage). On the main page in the ECM section, it says to check for a sticking or misadjusted plunger. What is the best way to go about this?
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rice.1
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Report this Post09-02-2014 09:25 PM Click Here to See the Profile for rice.1Click Here to Email rice.1Send a Private Message to rice.1Edit/Delete MessageReply w/QuoteDirect Link to This Post
This weekend I installed a new TPS. As I went to take off the old one, I noticed the plinth was actually stuck open. It was corroded enough that it got stuck. After I installed the new one, it lowered my RPM to 1400 at start up. Still high, but hopefully it will come down once it warms up. I haven't driven it for such a long time that I forget how long it takes to come down, if it ever even has.

For the hose, I just took electrical tape for now and taped it up, until I find a better fix.

Thanks for the advice everyone has given me. Taking just this small step in lowering the RPM has gotten me back into the barn and excited to work on it.
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Report this Post09-02-2014 11:33 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by rice.1:

For the hose, I just took electrical tape for now and taped it up, until I find a better fix.


I've seen those hoses open like yours was, but disconnected at the air filter with the canister itself plugged instead.
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