TCCoA Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
63 Posts
Discussion Starter #1
I'm sorry I can't remember who tipped me off to this but it was someone on this board. Anyway, my bird had terrible MPG and terrible HP(4.6). The car was like this for a long time. I did a lot of troubleshooting and a lot of parts changing. The PCM threw no codes. Well, to make a long story short, it was a vacuum leak! I was told to look at a vacuum line buried on the left rear of the intake and there it was, split wide open!! This line is right under the fuel rail crossover line so I never would have seen it without being told to look there. My point is this....thank you to whoever it was that posted pics of this and for everyone else, don't stop chasing the obvious stuff even if you don't see it the first time!!!
 

·
Sheepish
Joined
·
4,085 Posts
Got any pics of the location and specific hose? I may need to have a look in that general direction tomorrow...
 

·
Registered
Joined
·
63 Posts
Discussion Starter #3
Sorry, I don't have the pics. I'll try to explain the location for you. First of all, my IAC is on the back left of the intake. I don't remember what year Ford changed the intake, mine's a '94. If you look just forward of the IAC under the grey fuel line you'll see a short rubber vacuum line. It connects to a plastic line running towards the passenger side under the TB. The other end connects to a barbed fitting in the intake. That short rubber line is what split on mine. I've since heard that it's a fairly common problem. If you look just inboard and slightly lower than the drivers side rearest injector you should see the hose I'm talking about.

P.S. After fixing that one leak, my bird got 28MPG on a 200 mile trip to Indy. I'd never seen more than 21MPG before then!!

Good luck.
 

·
Sheepish
Joined
·
4,085 Posts
wrench71 said:
P.S. After fixing that one leak, my bird got 28MPG on a 200 mile trip to Indy. I'd never seen more than 21MPG before then!!

Good luck.
You've gotta be kidding me! I just improved my gas milage to 21mpg! That hose is DEFINATELY getting checked tomorrow! Thanks for the detailed description, since we have the same exact intake, it should be really easy to find. :D
 

·
Sheepish
Joined
·
4,085 Posts
Kaptn' Obvious said:
28???

28 MPG w/ a 4.6 V8

:2huh:

not that I don't belive you, but you might want to check your math

:D
Steve Dugan (1MTNCAT) still gets like 24mpg with 4.10s in his car! I think JL gets 26. So 28 isn't that unlikely, and if I can manage that...:headbang: :headbang: :headbang:
 

·
Registered
Joined
·
654 Posts
It might not be.

I dunno what's in the rear of my beast. they're highway gears of some sort.

@75 i'm tackin' about 2k

I average about 23-24 on the highway.

My car runs great I'm just saying that I don't see my car ever getting that kinda mileage

but on the other hand I had a 455 that put out 560 hp average 23 on the highway. of course i got like 8-10 in town, but that's another story <img src="http://theforum.dallasgothic.com/html/emoticons/devileyes.gif">

It'd be nice to think I could get close to 30 mpg but I don't see it happening

:D
 

·
Registered
Joined
·
1,598 Posts
Well, best tankfull was 26.7 mpg on my 5.4 bird, coming out of Chattenoga, north bound, with the temp showing 103 degrees outside, so I took it easy, and didnt pass evrybody on those uphill grades towards Rocky Top, and was startled to see that kinda mileage (the car was loaded-HEAVY) this a little better than the trip average of22,8 for almost 4k miles with 3.55 gears, go figure. and all I get goofin off running around the county is 17-18.....lol...I am a retired navigator and mathematician.......
 

·
Registered
Joined
·
526 Posts
Kaptn Obvious....

Your rear end gears sound like the 3.07's in my Cougar....I tack right at 2200 at 78. I usually average about 22MPG, but have been as high as 24.

There was a thread here that told you were to look on the door frame inside to see what code your car had...then had a link to a chart where you could match the code to your rear end gears.

I immediately looked at mine because I was interested. 3.27's in the Tbird, and 3.07's in the Cougar. Interesting stuff.

Thought you might like to know...
 

·
Registered
Joined
·
1,598 Posts
There was a metal tag on one of the bolts on my rear end that said 3.08, which was the right # for mn12's of the 94-95 persuasion......
 

·
Registered
Joined
·
63 Posts
Discussion Starter #11
I should have been more precise.......I filled up before my trip to Indy. I drove 171 miles to get there and filled up again. I used 6.1 gallons of gas. 171 divided by 6.1 comes out to 28.03MPG.
 
1 - 11 of 11 Posts
Top