I was looking at my engine and was wondering if any of this is at all important to my MPG and manifold pressure?







Any help would be much obliged.

 

The smog equipment is already gutted beyond repair.

The EGR situation needs fixed. It doesn't appear to be hooked up, whether this is because someone just disconnected it for the hell of it or if it stopped working; you need to get it straightened out. If it isn't working then I think it needs blocked off, or replaced. If it is blocked off then you should consider recurving the distributor.

You need to cap tubes coming out of the float bowls for safety purposes, they lead directly into the float bowls and you don't want gas splashing out.

Also verify that there is a vacuum line running from the distributor to that small port up under the carb. I see a line connected to it but I don't know if it's actually running to the distributor like it should be.

Look for uncapped vacuum ports on the manifold, those blue and yellow things are just vacuum switches; don't worry about them.

 

All right, does it surprise you that the carb needs a bit of tuning as well? Ha, it actually did run good at highway speeds.

Am I correct that this truck has a Holley 4180 on it?

Yes there is a hose leading to the distributor, however there is a vary small port that I did not take a picture of closer to the drivers side. I can take a picture of it in the morning if need be.

Thanks for tip on the blue and yellow switches, I had no frigging clue what those were for.

 

Hmm, No cats from the factory, is that right? The GVRW on it is a little over 8,800...

 

Yes, that's right.
carbureted 460's and 351's over 8500# GVW came with no Cat's.
The distributor should have it's vacuum plumbed through that yellow thermal switch on top of the thermostat housing so if the truck starts to overheat the idle speed is increased by bypassing the vacuum restriction.

http://www.flickr.com/photos/24183730@N03/2340584591/http://www.flickr.com/photos/24183730@N03/2340584591/ by http://www.flickr.com/people/24183730@N03/, on Flickr

The evaporative emissions system coming from the bowl vents is missing.
Is the charcoal cannister still there? (down by the radiator drain/alternator)
Float bowls without these vent tubes are available, or you could remove the tubes and plug the holes if everything is gone and you don't have to pass a visual inspection.

I agree, you need to reconnect the EGR or do a lot of tuning if you want it to run right.

As you can see from the above diagram there is no port on the drivers side of the carb... unless you live in a country where they drive on the left.

 

Have any of you had direct experience with plugging the bowel vents on this type of carb? I have not, but I have on a quadrajet, and it made it hard to start in hot weather. I ended up leaving it open, and putting a small hose with a upward curve on it, since you are correct, when you hit the brakes hard, fuel sometimes will splash out onto the manifold from the open vent.

We just went through a long thread where a guy had the same engine and same carb(the one with the motorhome) and even though he had the knowledge to take apart the carb several times, and finally got it all worked out, I believe he would admit now that it would have been easier and quicker in the long run to just buy a new aftermarket Holley. When you do that, you do NOT have to worry about plugging all the vents and the vacuum ports, they do not come with them.

And you also need to take the carb completely off and then the EGR spacer, and check the gaskets. The guy with the motorhome found his gaskets and part of is intake manifold eaten away underneath the spacer, causing a large vacuum leak.

 

I have some pictures of mine so you can see what is where and I believe somewhere on this forum I posted a scan of my emission label.

 

It should be fine plugging the vents, I did it before I replaced my 4180 and didn't notice a difference.

Both bowls are still vented into the air cleaner like any other Holley.

I just noticed that you have annular boosters in the secondaries.

 

I agree with Dave. If you don't have a lot of patience and experience with carburetors you'd be better off buying something like a 0-80457s.

 

I thought all late model 4180's were like this???

 

I thought they only had them in the primaries... I know the mustangs didn't have them in the secondaries, but they switched to EFI in 1986.

 

So I'm still a complete noob but where do I start?

Vaccum lines I'm sure, but what do I need for the EGR?

If I have too, I probably will get a new carb to replace this one. I just really don't have the cash right now but I don't drive it daily currently so I'm good.

 

If you look at my diagram there is a green line from the bottom port of the blue thermal valve/switch.

 

Oh, right, yes the cannisters are still there.

So from the blue port switch to the VDV to a T connecter, one side going to the EGR and the other going to the charcoal cannister.

Should I just go pick up vaccum lines in the right diameter and then get a VDV filter?

Assuming it works at all. I have no way to test it.

 

That's a vacuum diverter valve.

Check this thread for a list of all those acronyms.
https://www.ford-trucks.com/forums/7...ml#post6602805

The blue thermal switch inhibits vacuum unitl the engine is warmed up.
The white line goes from the 'E' port on the passenger side of the carb to the second port of the vacuum switch.
The green line goes from the first port of the switch through the VDV and on to the EGR.