Engine 93 LX - EGR Vacuum Line Location Issues

diesel farmer

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Nov 11, 2021
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I'm back to figuring out electrical wiring and vacuum issues. the 93 LX is running, but very rough at idle. I haven't checked the IAC or TPS yet - I am first trying to shore up wiring and vacuum issues (I don't know if my approach is correct?). I want to attempt to get the EGR working if possible. I posted a couple of pics of the EGR at the top of the manifold and the EGR Vacuum Regulator. Here are my questions after doing a little digging.

1. The EGR line is blocked off (see pic 37) and there are no lines going from ERG to the Vacuum Regulator. Looking at a vacuum diagram, it looks like there should be one vacuum line running from the EGR to the Vacuum Regulator, and another line from the Vacuum Regulator to the manifold. Is this correct? If so, where on the manifold does the line run to?

2. In pic #38 there are 4 wires cut off. Do these likely go to a smog device? All of the smog has been unhooked from what I can tell.

3. In pic #37, there are no vacuum lines running in/out of the top of the manifold near the throttle body. What lines are suppose to run through that location?

Thanks for any help!!
 

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evintho

5 Year Member
Nov 12, 2003
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The vacuum line that's plugged coming off your EGR valve, runs to the EGR vacuum regulator. The second line that comes off the EGR regulator runs to the manifold vacuum assembly, underneath the rear of the upper intake manifold. It attaches to one of the two skinny tubes that protrude from the side of the vacuum assembly.

upper intake6.JPG


The 4 cut wires in your pic probably control the TAB and TAD solenoids. TAB wires are Red and White/Yellow tracer while the TAD wires are Red and White/Lt Green tracer. Just peel back the tape and have a look. Looks like it might be them.

Also, looks like your missing one of the water tubes off the EGR spacer. There should be one on each side......

upper intake4.JPG


Those aren't vacuum lines, they're water passages. Coolant circulates through the EGR spacer. The front one attaches to the water tubes attached to the lower intake. The rear one......I'm not too sure about. I'll have to figure that out.

upper intake 3.JPG
 

diesel farmer

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Nov 11, 2021
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A very helpful reply. I will check the wires and study up on whether it might be worthwhile to hook up the smog items (TAB and TAD) and the water line to the egr spacer. It shouldn’t be too difficult to hook up a line from the EGR to the manifold.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
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A very helpful reply. I will check the wires and study up on whether it might be worthwhile to hook up the smog items (TAB and TAD) and the water line to the egr spacer. It shouldn’t be too difficult to hook up a line from the EGR to the manifold.


Do you have cats? if not, i wouldn't worry about it. I personally would have just left the ends of those connections loose, vs lop them off like that.

Keep in mind, those two red wires are Key-on, 12V+ power at all times. I actually think they come of the ECU relay. You really want to insulate them so they don't accidentally short to ground and cause you some issues.


If you get the EGR functioning, you want to replace the two coolant lines to the spacer. You may want to pull the spacer off and install fresh gaskets first and clean it up. Who knows what crud is inside of if the gaskets are good.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
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Well, the EGR is a separate system really. With regards to the TAD/TAB wiring, i would make that cut safe by taping up or heat shrinking the wires individually, and call it a day.

With regards to the EGR, it looks like you are missing the vac lines to the regulator. There's a few of them in that area and it gets a little confusing because there is a vac reserve in the fender as well. the HVAC is fed off these lines too. Do tou have the little vac line poking out near the EVAP connections? where does that run to? There shouyld be a small line coming in from the fender as well as that's where the vac canister lives. If gives you a source of vac so that at WOT your HVAC vent positions won't change.

Here's a diagram. Yeah, it's a tad confusing i know.

1640025472069.png

1640025346244.png
 

diesel farmer

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Nov 11, 2021
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It's pretty barren on the passenger side! Do these pics help? I don't think there is a vacuum canister in the fender on the passenger side. I assume it looks the same as or similar to the vacuum canister in an 84 SVO, correct?
 

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Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
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yeah, it's inside he fender and similar to the early cars. They both poke through near the firewall

1640027143692.png


The round one is for the HVAC. the cylinder one is for the TAD/TAB
 

diesel farmer

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Nov 11, 2021
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did u ever find a fix for this I'm having the same issues
Actually, I'm hoping to get the engine back running in the next couple of weeks, time permitting. I am doing an explorer intake swap along with some other upgrades. Before I started the swap I had it idling decent, but the idle problem I think was related to a vacuum leak primarily and the TPS was off adjustment.
 

mattys91gt

Active Member
Feb 3, 2022
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Actually, I'm hoping to get the engine back running in the next couple of weeks, time permitting. I am doing an explorer intake swap along with some other upgrades. Before I started the swap I had it idling decent, but the idle problem I think was related to a vacuum leak primarily and the TPS was off adjustment.
I'm having such a brain fart hooking the vacuum lines back up does it split off into a t all week I've been going nuts it ran good last night and I switch it to shorter lines and it runs like crap but I didn't drive it it's only at idle tho correct