crazzywolfie

been a while since i needed to post here but picked up a 94 f150 with the 5.8. i got it pretty cheap since it had a small fire under the hood on the passenger side exhaust manifold area.i think the fire might have been caused by a leaking exhaust at the flange causing something to catch fire but really don't have too much of an idea yet. the guy i got it from said it was spraying fuel near the back of the engine but i didn't see anything when i put power to the truck. it doesn't seem to leak fuel or anything in that general area on the ground. i think it might have been smoke from the exhaust he mistook for fuel. anyways i am looking for some vacuum diagrams for this things to put it all back together. i am pretty sure i can guess where most things need to connect since it is color coded but there is a couple thing i am not sure about. i am pretty sure i got all the big vacuum leaks fixed and it seemed to run pretty good once we put some fuel in the 1 tank we were told works.

something else i wasn't sure about was the intake. is it a 2 piece intake on the 5.8's? if so would someone happen to know what size bolts are used to hold the top to the bottom. i think i noticed 3 or more missing like someone might have tried or was planning on taking the intake off. also how bad of a job is changing plugs on this thing. i thought the guy i bought it from said he changed all the plus but there was 3 new ones in the box on the seat when i want to go pick it up today. i am also certain he said a couple of the ones were a nightmare to change. i can't really think of anything else right now but am most likely going to think of more once we start tearing into it. it seems like a solid truck that has been taken care of pretty good considering how rusty vehicles can get around here.

Steve83

The vacuum map is on the VECI label on the hood above the brake MC, but here's another one:


(phone app link)

All EFI intakes are 2 piece (a lower intake, and a plenum). The missing bolts are the same size as the ones that are still there, except the Right center, which has a T40 head. But if you grind away the plenum near it, you can use a common bolt & socket:


(phone app link)

Looks like it's also missing the R side support's nut (and maybe stud), and at least one EGR bolt. This & the NEXT dozen might interest you:


(phone app link)

crazzywolfie

ok thanks. ya it is missing all the bolts you mentioned plus some. i really have no clue how many bolts it was missing. i have a feeling i might have seen all the bolts down the 1 side of the intake were missing but hoping not. also need to replace the studs and exhaust flange. on the 1 side. at least we got this truck just in time. the 95 and my elcamino need exhaust studs also so i can make a day of it.

crazzywolfie

Ok you would happen know what thread pitch and bolt length on the intake bolts are. After looking again it looks like the only one holding the intake on is the t40 one. I have a feeling the t40 ones is the reason they didn't take the intake off

Steve83

You should browse your local JYs for '88-96 5.8L engines to get parts from. Most JYs don't charge anything for fasteners, if you're buying something else substantial.

The original plenum-to-lower bolts are 5/16"-18 x ~1.5" with hex head, integral washer, and ~1/2" unthreaded shank. Some have a ~1/2-long stud on the head. If the fuel rail wraps around the front, the front 2 plenum bolts have a hard-plastic cap to protect the flexible fuel tubing in a collision.

This shows how to get at the T40:


(phone app link)

Replacement high-temperature studs & nuts are not available for the exhaust flanges; the best ones I could find were cheap .


(phone app link)

crazzywolfie

thanks. there is really not much this old in the recyclers around here. most of the time stuff is crushed since it is rotted out and really not too much there to salvage or make money off of in the land of salt, sand and rust. we got lucky finding a truck as clean as we did especially with the mileage. i think i even talked my dad into only driving this in the summer only and keeping his old one as a winter beater as long as it keeps moving.

thanks for the link to those pics. i really don't plan on removing the intake unless needed but it is still nice to learn some of the trick on how to get it off a bit easier. i do have a feeling i may need to pull it tho to replaced a valve cover gasket but hoping not. i really have never seen a intake that seems so weirdly shaped

hahaha funny you mention them doorman studs. we just finished installing some in the 95 today. only did 2 and replaced the flange and was going to save the other 2 for the 94. we used a thread cleaner on the bolt holes and bolts and still struggled to get them studs in all the way. also did a stud on the elcamino while we had the torches out. i really don't like studs. i like the way they are on a dodge. just cut the bolts and install new ones.

Steve83

It's not unknown for the plenum-to-intake gasket to suck in & leak when all the bolts are tight. If they're loose/missing, and there's a CHANCE that someone cranked that engine even once, I'd change it out, and use CopperCoat to hold it in-place.

I'll be using Nickel AS on those studs & nuts:


(phone app link)

crazzywolfie

hahahaha we would have drove it home if we had enough gas in the 1 tank lol. we were running it like that but didn't realize the bolts were missing till we looked things over better. it did seem to run pretty decent once we fixed some of the vacuum leaks and put a bit of fuel in the 1 tank. i am hoping the gasket doesn't need to be replaced but if it does need to be replaced i at least know how it should be done. i will definitely be using Nickle AS. i think that is what i usually use on most bolts that could be questionable in the future.

Steve83

Don't use AS on everything - the truck will fall apart (BTDT). Blue threadlocker is an effective anti-seize, but it keeps things in-place.