Vacuum line routing (Page 1/4)
Scuba_steve45 MAR 13, 04:45 PM
I have a 1985 Fiero with an iron duke 2.5L and the Isuzu manual trans. I’ve been trying to deal with a high idle issue and was looking through my vacuum lines and got a little confused when I got to the vacuum canister lines.

I’ll attach an image bellow

I have an extra vacuum lines attached to the hard line of the vacuum canister. The vacuum diagram says that it should connect onto the TBI unit but I found it just pointed down at the ground. The is also already a vacuum like going into said vacuum port.


------------------
Daunte

shemdogg MAR 13, 09:26 PM
There should be a vacuum diagram on the engine info sticker but if not heres what I found


That hose may go to the cruise control

shem
Scuba_steve45 MAR 13, 11:25 PM

quote
Originally posted by shemdogg:

There should be a vacuum diagram on the engine info sticker but if not heres what I found


That hose may go to the cruise control

shem



According to the vacuum diagram the hose I found hanging should go to the throttle body but on mine there’s a hard line going from the vacuum manifold “tree” on the intake manifold to said throttle body port. I’ll attach an image below. Is this wrong? It’s been like this since I bought it.
Patrick MAR 14, 04:03 AM

With that mini-filter sticking out of your valve cover, what air filter canister are you using on your TB?

Scuba_steve45 MAR 14, 08:59 AM

quote
Originally posted by Patrick:


With that mini-filter sticking out of your valve cover, what air filter canister are you using on your TB?




Hi Patrick!

So when I first got the car I decided to do a “hot air intake” and cut up the stock air cleaner and put in that mini air filter on the valve cover where the hole was that the stock air cleaner went into.
I saw a bunch of people do it with no problems so I assumed it was ok.
82-T/A [At Work] MAR 14, 12:54 PM

quote
Originally posted by Scuba_steve45:
Hi Patrick!

So when I first got the car I decided to do a “hot air intake” and cut up the stock air cleaner and put in that mini air filter on the valve cover where the hole was that the stock air cleaner went into. I saw a bunch of people do it with no problems so I assumed it was ok.



Hi Steve, personally, I'd recommend against that. You're actually losing horsepower by doing this. The air cleaner / system on the Fiero is actually REALLY, REALLY good. When you re-install the factory air cleaner, you're effectively pulling cool air directly from the side air intake, which is much better than the hot air that you're pulling from the engine bay.

Another thing is... with the factory air cleaner hooked up to the crankcase ventilation, you're sucking back into the intake any "blow-by" ... but the way you have it now... the blow by isn't being sucked out of the crankcase, and therefore your exhaust will have smoke coming out during shifts and things like that. If you want to improve the air flow, the thing that people often do is break out the water separator on the air intake, and replace the factory air filter with a K&N air filter.



quote
Originally posted by Scuba_steve45:

I have a 1985 Fiero with an iron duke 2.5L and the Isuzu manual trans. I’ve been trying to deal with a high idle issue and was looking through my vacuum lines and got a little confused when I got to the vacuum canister lines.



My daughter has the exact same car (85 2m4 w/ 5-Speed Manual). I'll try to take some pictures tonight if you can hold out. I'll take pictures of the TBI unit with all hoses attached, the intake with the vacuum tree, and I'll also take pictures of the air canister (which is ONLY for Cruise Control, by the way). I'll respond to this thread with the images.
Scuba_steve45 MAR 14, 01:22 PM

quote
Originally posted by 82-T/A [At Work]:


My daughter has the exact same car (85 2m4 w/ 5-Speed Manual). I'll try to take some pictures tonight if you can hold out. I'll take pictures of the TBI unit with all hoses attached, the intake with the vacuum tree, and I'll also take pictures of the air canister (which is ONLY for Cruise Control, by the way). I'll respond to this thread with the images.



Hi! Thank you so much for your reply you’ve been very helpful with my Fiero issues in the past (mostly idle stuff lol)

I understand the downsides of the hot air intake although I did not know smoke would come out the exhaust during shifts because of it. But I am still young and just out of highschool so I do dumb things haha.

I’m at work currently so no rush on the pics. Thanks again!
Patrick MAR 14, 02:37 PM

quote
Originally posted by Scuba_steve45:

I saw a bunch of people do it with no problems so I assumed it was ok.



Where'd you see it being done? It certainly wasn't here.

I won't give you a bad time over it, but you'd be much better off to return the air filter system to its original condition. Nothing has been gained by doing what you did. If anything, it's been detrimental to engine performance. Buy hey, you're learning!
Scuba_steve45 MAR 14, 03:37 PM

quote
Originally posted by Patrick:

Where'd you see it being done? It certainly wasn't here.

I won't give you a bad time over it, but you'd be much better off to return the air filter system to its original condition. Nothing has been gained by doing what you did. If anything, it's been detrimental to engine performance. Buy hey, you're learning!



Haha I saw one or 2 forum posts on here about it… full of people saying it’s bad for performance. I just like the way it sounds and looks. I might eventually change it back to stock if I ever get a stock air cleaner lol.
82-T/A [At Work] MAR 15, 08:48 AM
I didn't get a chance to take pictures... but I will do it today. I'm cleaning the house since my wife has guests coming over later... but I'll be in the garage so I don't have to hang out with the girls... so I'll take pictures then.