Butchered 400 vacuum system

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Apr 9, 2014 | 01:21 AM

700hauler

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Mountain Pass

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From: Reno NV

Butchered 400 vacuum system

Looking to pull from some of the members' expertise on this matter. The engine has a pretty distinct tick/knock...but it doesnt do it all the time. Im hoping its a vacuum issue. It doesnt appear to have EGR...may have been removed by previous owner? Here are a couple of pictures of the what I believe to be problems with the vacuum system (I know nothing about this stuff however). The first picture is of the vacuum advance and a lack of any lines whatsoever going into the vacuum switches:

The second picture is of the vacuum tree near the firewall...notice the larger line looking thing that has been cut (above the red wire)? It appears to be part of the vacuum tree. Am I losing vacuum there? Does it need to be plugged?

Thanks for any help

Apr 9, 2014 | 08:30 AM

mikeo0o0o0

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From: Stanley, VA

If you're talking about the hose that I've highlighted, that's the A/C liquid line and doesn't have anything to do with the vacuum system.

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Apr 9, 2014 | 10:36 AM

700hauler

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Mountain Pass

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From: Reno NV

Quote:

Originally Posted by mikeo0o0o0

If you're talking about the hose that I've highlighted, that's the A/C liquid line and doesn't have anything to do with the vacuum system.

Yes that was what I was referring to. Thank you thats good to know. Obviously the truck used to have AC but no longer does. THe previous owner kind of hacked it up when he added on the Edelbrock stuff. Any iput on the other vacuum lines (or lack thereof) on the front? There is a hole in the top of the vacuum advance. Wasnt sure if that was supposed to be plugged. ANd I was under the impression that there should be at least a few lines going into the vacuum switches coming off of the thermostat housing..

Apr 9, 2014 | 11:52 AM

mikeo0o0o0

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From: Stanley, VA

You didn't say what your truck is so judging from the picture in your signature and the fact you're dealing with a 400, I'm guessing you've got a '77.
See if this will help.

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Apr 10, 2014 | 07:09 PM

700hauler

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From: Reno NV

You are correct. Sorry for the lack of information. It is a 77 Ranger XLT with the 400 and no emissions stuff that I can tell...and no EGR. half of the stuff shown in that diagram is non existent on my truck.

Dec 3, 2014 | 08:26 PM

ChrisC.J.

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have you figured out your vacuum situation?

I have a 77 ranger with the 351 modified engine in it. I am wanting to get rid of my smog stuff on it. Have you had any luck with your vacuum system? If so can you post pictures of your engine so I have a starting point on which hoses i need and which ones i don't.