Vacuum Line
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Joined: Aug 2002
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From: Fulton USA
Vacuum Line
Does anybody know where the vacuum line that is the hard plastic encased in a loom tubing connects to from the vacuum dist. block on my '93 4.0 2WD? I must have knocked it loose when I was changing the plugs and wires and I cannot see where it goes on the right side of the block.
I also assume that is why the idle is a little rougher now and the mileage is down 13.5 city, 18.5 hwy. It could also be faulty spark plug(s) or wire(s) out of the box. Has happened before over the years on other applications. The van has 123,200 miles on it.
Also I did plug the outlet at the dist. block for the time being. The diagram sticker on the hood seems very vague to me.
I also assume that is why the idle is a little rougher now and the mileage is down 13.5 city, 18.5 hwy. It could also be faulty spark plug(s) or wire(s) out of the box. Has happened before over the years on other applications. The van has 123,200 miles on it.
Also I did plug the outlet at the dist. block for the time being. The diagram sticker on the hood seems very vague to me.
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Joined: Apr 2000
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From: PNW
Vacuum Line
Well, I'm not exactly sure from your description which line you are referring to, but there are at least 5 vaccum lines. One for power brakes, one for the PCV valve (both should be obvious), one for the climate control and one for the fuel pressure regulator. There is also one line that goes to the vacuum modulator on the transmission.
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From: Fulton USA
Vacuum Line
It must be the fuel pressure regulator because I know what the others go to- heat/ac, power brake booster, transmission, cruise control, and pcv valve. I just can't see where it goes. It's the only one that is the hard plastic encased in loom tubing and is routed around to the rear of the engine block and goes underneath the coil pack. From there I have no clue where it connects to because I can't see past the coil pack looking from the inside of the van. I don't know what to look for because it is hidden from every view. I installed clips on the rest of the lines so they don't pop off anymore. Being very frigid outside doesn't help the matter any either.
Can somebody help me what to look or feel for? I haven't had a chance as of yet to gety back in there.
Can somebody help me what to look or feel for? I haven't had a chance as of yet to gety back in there.
Logistics Pro
Joined: Jan 2002
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From: suburban atlanta
Vacuum Line
The fuel pressure regulator on a 4.0 is on the pass side of the intake fuel block, less than half way back. To really see it, you have to pull the throttle linkage cover and the air intake tube. The vacuum line runs alongside the intake towards the rear, and then turns to the drivers side. Dunno if it is encased in a plastic cover, but the one I am familiar with is not..
tom
tom
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From: Fulton USA
Vacuum Line
That's the rascal. I knew it had to go somewhere but I thought I would see if anybody would know where it went before I got back in there.
Also would that create a rich condition and affect fuel mileage?
Also would that create a rich condition and affect fuel mileage?
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From: PNW
Vacuum Line
Yes, it's possible because the regulator is referenced to the manifold vacuum to maintain a constant pressure drop across the injector. For example, without the vacuum, the fuel pressure will be about 40 psi (can't remember the exact pressure, so this is a rough number) above atmospheric pressure (about 55 psi gauge), whereas with the vacuum line it will be about 40 psi above the pressure in the manifold (which is lower than atmosperic pressure).
