4180C vacuum ports
 

Hi. I've got an 86 F-150 with 351W and Holley 4180C carb. The engine was replaced with a reman before I got it, and most of the emmisions control stuff was ripped out. Basically, the guy hooked up just enough of the vaccum lines to get it to run, but I think some of them are wrong. For instance, the vacuum advance is hooked directly to manifold vacuum, but the VECI label shows it going to the spark port on the carb. Does anyone have a diagram that shows which ports on the carb are which (i.e. spark, egr, purge, etc.), or at least be able to describe which ones are which? I assume all of the ports on the spacer would be the same as manifold vacuum, right?

Thanks.

4180C vacuum ports
 

https://www1.autozone.com/images/cds...3d800ce68f.jpg

https://www1.autozone.com/images/cds...3d800ce68e.jpg


Looking at the diagrams above, I believe you might have a mess on your hands. What I would do first is run the engine at idle, and find a port on the carb with no vacuum on it. While holding your finger over the port, rev the engine a little and see if it suddenly has vacuum. If you find a port like this, I would hook the dist to it and see how it runs. If you have manifold vacuum on the dist now, you will probably have to reset the idle speed.


I just noticed that the diagrams above don't have a connection to the distributor. But they are listed as 85-86 5.8 liter diagrams. So they are probably of no help at all. I see a MAP sensor in the above diagrams, so it must have a computer and a dist with no vacuum connection.

4180C vacuum ports
 

I've seen those same diagrams (I think they're from either the Haynes or Chiltons manual), but they don't match what I have (even though I do have an 86 w/ 5.8L engine). Mine has no electronic control. It uses a Duraspark II system. I can take a picture of my VECI label and post it on here if that would help. Basically, I'm just trying to figure out which physical ports on the carb match up with what's being shown on the vacuum diagram.

Thanks.

4180C vacuum ports
 

Not quite sure how to best help you. I was/am in a similar situation, though I think I have it mostly nailed down now.

Having the same engine/carb/duraspark, here is what I know, which isn't much.

The dist. VA on mine is now hooked to the far right port at the base of the carb. This is also true of the throttle dashpot (deceleration kicker)

The two ports (trees) located at the right front, and center rear of the manifold are where things get hazey for me. The Tranny modulator valve is connected to the aft tree as well as a nightmare of other hoses I have yet to trace.

The emissions decal makes very little sense to me. It lists all of these abbreviations, yet I have nothing to cross reference them to. None of my manuals give me a description of what each of these units is, looks like, nor where it is located.

That is a start for you I hope. Let me know if you are able to trace and identify all of this mess. I would be very interested in what you find.

4180C vacuum ports
 

Vacuum advance is connected to a ported source, not positive on the 4180 but holleys normally have a port on the passenger side right above the idle mixture screw on the metering block. EGR valve can get complicated but most everything else runs off manifold vacuum

4180C vacuum ports
 

DeKuma,

Thanks for the post. I totally agree with your assessment of the emissions decal. Most of it is total gibberish to me. Especially since most of what it is showing isn't even there anymore. My main concern is getting the vacuum advance, throttle kicker, mainfold heat valve, exhaust heat valve, and egr hooked up right.

That's interesting that your TK is hooked to the same port as the dist advance. I was able to at least figure out from the diagram that it's supposed to be hooked up to manifold vacuum through a temperature controlled vacuum switch so that it only gets vacuum after the engine warms up. Same goes for the manifold heat valve (which is hooked straight to manifold vacuum right now) and the exhaust heat valve (which isn't even hooked up right now).

4180C vacuum ports
 

Huh.
It would not surprise me that some of mine are wrong. I have been messing with them for a while. Hell, half of them were not connected and plugged or unplugged. Some that were off also had tees that connected other components. I will swap the throttle kicker to manifold vaccum, and try to make heads or tails out of the rest.

4180C vacuum ports
 

Here's a site that has alot of the abbreviations that are on the diagrams

http://100megsfree4.com/dictionary/

It just so happens I have been going round and round with the emissions thing too.

My 351w came out of a 79 cougar, and I kept everything intact. So far so good till I put headers on the engine. Then it started pinging.
I noticed the egr seemed to not be working, so I put straight manifold vacuum on it, and it still would not work. I actually cut it apart, and that's when I found out that the egr will not work without a little backpressure from the exhaust. It had this bleed-off hole in the middle of the diaphram, so I blocked it off. I made a clamp so I could put it back together, and then it worked too good. The egr would open wide and the engine would run rough. That's when I realized these things are carefully calibrated to each engine combo.
What I ended up doing is putting a new egr on, and also put bigger jets in the original 2bbl carb. It had #55's in it and I found an old 1960's ford 4bbl that had #58's in the secondaries. I put these in, and with the egr not hooked up, it still pinged a little, but with the egr hooked up, it quit pinging. I guess it was working a little bit afterall.

The upshot of all of this is, I need to spend $170.00 for a 4bbl manifold(I have a little holley 4bbl) and the original guy who started this post needs to buy a new 4bbl non-emissions carb. Then our engines would be happy without all those hoses and wires.