Engine What can i remove from my vacuum system?

omen

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Aug 11, 2020
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I have an 89 5.0 LX, smog removed, AC removed, EGR removed, Charcoal canister removed, cruise control removed or didn't come with the vehicle, not sure which.

My question is now, do I need to keep anything hooked up electrically or to the vacuum system? From what I can tell from looking at diagrams and of the engine bay, I should be able to leave everything on the passenger side of the vehicle unhooked as far as vacuum lines (not counting the FPR.) Which would leave only the brake booster, PCV and fuel pressure regulator, I believe, unless I'm forgetting something.

At the moment I'm trying to eliminate a vacuum leak as a possible cause of a problem i'm having.

Thank you anyone for any help/advice!
 
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Monkeybutt2000

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Still running a heater? All you need to leave on the passenger side is the vacumn tee right above the where the ac goes into the firewall. One goes to engine vacumn,one goes into firewall for heater controls and one goes into inner fender for vacumn reservoir. You can remove all that crap on the pass. strut tower as well.
 

omen

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Still running a heater? All you need to leave on the passenger side is the vacumn tee right above the where the ac goes into the firewall. One goes to engine vacumn,one goes into firewall for heater controls and one goes into inner fender for vacumn reservoir. You can remove all that crap on the pass. strut tower as well.

Yeah still has heat. Okay thanks you're talking about this thing right?

Also, I still need the vacuum resevoir?
 

jrichker

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What is the nature of your problem that causes you to disable all the vacuum operated accessories?
 
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africansnowowl

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I removed a lot of that stuff as well. It sounds like your vacuum setup is the same as mine, except I currently have AC. I just have the PCV lines, line from manifold to fuel press reg, the source vacuum line that goes from the intake manifold to the tree, the line that goes from manifold to the MAP sensor, and the line from brake booster to vacuum tree. When I did this I made sure to replace every single piece of vacuum line whether it looked good or not, and use hose clamps. I thought this would fix my idle issue, but no luck. At least I can be 100% sure there's no vacuum leaks though lol.

FYI you can find vacuum hose that is very similar to the pre molded PCV lines on the bottom of the intake manifold in the help section at Autozone. I used that and some plastic 90 degree bends to get everything lined up correctly.
 

omen

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Thanks for the help guys, I know I don't have any leaks now atleast with the vacuum lines, thinking i might have one on the manifold somewhere.
 

jrichker

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Thanks for the help guys, I know I don't have any leaks now at least with the vacuum lines, thinking i might have one on the manifold somewhere.
Like I said before, what's wrong that makes you think that you might have a vacuum leak?
 

omen

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Like I said before, what's wrong that makes you think that you might have a vacuum leak?
RPM drops that get worse as the RPMs get higher and the engine gets hotter, also a high pitched whistle that doesn't start till the engine warms up a bit.
 

jrichker

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if you have an aftermarket throttle body, that the most common source oft he whistle.

If you are having Idle problems, here is the answer....

You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 250,000 hits, which indicates it does help fix idle problems quickly and inexpensively.
 

omen

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Ill check it out but the problem is not only at idle, it's a whole different problem.

Was checking TPS voltages and found out about a bad connection inside the computer, got a spare to check how it works with a working one tomorrow.
 

omen

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That doesn’t sound like a vacuum leak. Sounds fuel or ignition related
Fuel is good unless the problem is at an injector, also changing spark plugs today to get a better idea of what's going on in the ignition regard.

With the whistle though, when it's going and then you shut the car off it makes another sound similar to the whistle sound like it's finally letting out the last of the pressured air. I might be taking off the upper manifold today or in a couple days.
 

General karthief

wonder how much it would cost to ship you a pair
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From your description I would be looking at the brake booster/check valve or the vacuum canister/check valve.
It's hard to tell from the keyboard side.
You can take a funnel with a hose connected to it to help to locate the sound.
 

Noobz347

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Ill check it out but the problem is not only at idle, it's a whole different problem.

That is a diagnostically silly statement. You really should review the checklist. If you get through it from the top to the bottom, you will discover what on the car works and what doesn't or isn't.

There are lots of things that it [could] be. The checklist saves you time and part tossing.
 
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omen

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That is a diagnostically silly statement. You really should review the checklist. If you get through it from the top to the bottom, you will discover what on the car works and what doesn't or isn't.

There are lots of things that it [could] be. The checklist saves you time and part tossing.
Like I said I'm going to lol. The computer is broken so I'm testing another one, I would have found that on the list anyway.
 
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7991LXnSHO

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The whistle from the throttle body only at idle tells me my IAC is working! :) I might round off the passages after I’m done tuning. So maybe never?
It does sound like yours is from something like the General said to check. Fixing the leak will be a start on getting it to run right.

RPM drops that get worse as the RPMs get higher and the engine gets hotter, also a high pitched whistle that doesn't start till the engine warms up a bit.