REALLY bad gas mileage

[Tourture]

ok ok, i know that there have been numerous posts on this subject, but i'm going absolutely mad with this problem.
i am not even getting 200 miles to a full tank on my 93 XLT.
i have replaced the wires and plugs ( jacobs 8.5 and bosch plats +4), have replaced the stock filter with a K&N drop-in...still bad mileage.
i am going to clean the maf sensor tonite (i'm assuming it hasn't been done since 93)
so here goes...
all i need to do is remove the two torx screw and pull the sensor, cleaning the wires w/ brakleen, and then replacing the sensor....?

next, what other suggestions do you have? this is a bad situation already, as i am getting very tired of filling up every couple days.......eric

 

[Tourture]

the performance as a whole isn't that bad....acceleration is good (for a brick, but there is a bit of knocking and pinging going on.....
eric

 

[velcrofly]

Well,
mine has been doin' exactly the same thing now for about a month! All of a sudden, crappy gas mileage without any real performance loss. But my engine light comes on every now & then (sometimes as soon as I pull out of my driveway & sometimes not for hours) I also am not even getting 200/tank & was gettting about 260-280/tank.

Where would you test the fuel pressure?
What is correct pressure?
What is too high of pressure?
About how much is the gauge?
About how much is the regulator?

'Bout ready to drop it off at the Dealer $$$$$ (gulp) & have them figure it out.

BTW: I have already tried cleaning th MAF with NO improvements.

------------------
92EB
Some days you get to be the Statue,
Some days you get to be the Pigeon!!

[This message has been edited by velcrofly (edited 11-10-1999).]

[This message has been edited by velcrofly (edited 11-10-1999).]

 

[Extreme4x4]

If your check engine light is coming on, your O2 sensors are probably bad. There are 2. You can get them from Ford or Napa (I would stick to these 2 for quality). Your O2 sensors are the main component in computer contolled vehicles. They tell the computer what the engine is doing, so it can make adjustments accordingly. These are the first thing to look at for bad gas mileage. Then there is the pressure regulator. These are a common problem on the 4.0. They are not expensive (about $50). Your Ford dealer will have many of them (this tells you it is a problem). O2's recommended replacement is around 70,000 miles....... for the pressure regulator, then won't normally last over 100,000, usually much less. Just because the vehicle runs, does not mean that these parts are ok. Computer controlled vehicles will continue to run till there is a major computer fault, or a major failure. This is built into the computer, to get you home, and till it can be fixed.

 

[Cruiser]

Fly..
Just had the identical problem on my 92 Sport. I was used to getting about 21MPG..HWY but dropped to 11 on the way out to TX from CA. Ford dealer had it for a long time; changed the O2,MAF, and press reg. The last one did the trick back up to 350+ mi per tank. The mech said normal range for the press was 30psi, mine was peaking out at about 90...bad thing. Paid $400 for the MAF and O2, and $127 for the pres reg. Oh yeah my 92 only had one O2 sensor. Works for me...

 

[Ira]

You could have a bad fuel pressure regulator. If it is bad, it could be trying to inject too much fuel into the cylinders because of excessive pressure. You can test this by using a fuel pressure gauge.

I would assume that since it is using so much fuel, it is also running badly, from a performance standpoint. Another longshot is a clogged exhaust system...converter, muffler, etc.

Good luck.

------------------
Ira

91 XLT 4x4

 

[Extreme4x4]

Wow, I didn't know the 92's only have one, that is a trip. Thanks. My 93 has 2........ They really hosed you on the price of the parts. The O2's run about $75 and the pressure regulator is about $65 (over the parts counter). Service departments are sucky about prices on parts...... I wish we made that much on parts at our shop. Hopefully that price includes labor. Anyway, like I had said, those two would be where to look. Dead Link Removed) Good luck !!!!

Gloria
93 EB, 4x4, 4-door, lighty? modified Explorer
94 F150 Lightning

 

[Cruiser]

Yeah.. good call extreme. I got a feeling i got the screws put to me, but i'm new in town and didn't have a choice but take it to the dealer. Hence the "hosing". I forgot to mention those prices did include labor....and changing the air in my tires...boy i hate it when that comes due.

Good luck.

92 Sport

 

[S.Matsushige]

Eric as Ira and Gloria mentioned, I would check the fuel pressure regulator. The one in my '91 went and initially there was a slight miss which turned into a smoking engine which felt like a four cyclinder engine instead of a six. My mpg started dropping long before this happened. After the fix, the engine ran smooth again and mileage came back up. Its a easy fix and not expensive if you do it yourself. Hope this helps.

 

[CBoug76]

All i have to Say is, Are you running with 87 Octane Gas? if not, you SHOULD be ONLY using 87 Octane in a Stock Engine! FORD has Tech Builtens that it issues to all the Dealers telling them of common problems and soulitions they find, and this is a Common Problem! if you run 94 octane it will ping, Mileage will drop, and your Pistons will build up with carbon!(which is bad)

Chris

 

[Garrett]

Your fuel pressure regulator is bad - don't mess with the O2 sensor! Those things go bad a lot due to the different fuel additives these days. Your car is showing the exact symptoms of a bad regulator - don't bother with checking the pressure, mine showed fine pressure, but it was still bad! Go figure.

Good luck!

 

[KyleC]

I have called every parts store near me and they have all told me that the pressure reg. is a dealer part. Local Ford dealer wants $127 over the counter. I liked the sound of the $65 better....

 

[velcrofly]

hey Kyle,

my Ford dealer told me $62 plus change.
I plan on changing mine in a couple of weeks (getting bonus $$$) hoping that will fix my problem. If someone close to you could maybe find one for that much and ship it to ya. If not, give me a yell back and maybe we can work something out.

------------------
92EB
Some days you get to be the Statue,
Some days you get to be the Pigeon!!

 

[Tourture]

Well, the truck came back from the shop and they still couldn't find anything wrong...?
they told the the fuel pressure regulator was fine, as well as the o2 sensors. Now, I'm not totally convinced about the fuel reg, but what else, if anything, can i do here?

gettin more fed up every day with this crap....
eric

 

[Garrett]

You did the same thing I did. I took it to two shops as a matter of fact, then I took it into my own hands. Both shops tested everything, changed all kinds of sensors - except the fuel pressure regulator because they said it was "fine". Well, screw that!

I changed it out ($160 at the dealer, my local shops didn't carry it either) and the truck was fine - just like new! I went and told the shops, and they just stared blankly, just as I am sure they did as they tried to figure out the problem in the first place!

Replace your sensor! I won't guarantee it, but I am pretty damn sure that's your problem! Hope this helps to make your decision! Good luck.

 

[velcrofly]

Garrett,
a few posts up you said "-don't mess with the O2 sensor!"
now your saying to "Replace your sensor" ?????? i'm confused!

was the $160 for the pressure regulator?
if so, where do you people find these dealers? that's outragous!!!

------------------
92EB
Some days you get to be the Statue,
Some days you get to be the Pigeon!!

 

[Tourture]

I believe garett meant to say "replace your regulator". Don't worry my friend, I have already made the decision to replace the infernal part, I figure, what the hell, it already been to the shop a few times for this, so what's a few extra bucks?
Good thing I have a few inside contacts at Ford that will get the parts for me at COST!

Eric

 

[KyleC]

What is the part # for the $65 reg?

If it is the same as my $127 one I think all you guys who are near one of these places with cheap regulators could make some money off of this. Buy the reg for $65 and sell it for $75+S&H to the unfortunate people like me whose dealers say $127 or even higher and all sides are happy.

Just a suggestion......

 

[velcrofly]

Ok, now I'm ticked off!!!!!!!!!!!!!!!

just called the dealer this morning to get the part #, well guess what the price is now $143.83 Part# 9C968. When I called a couple of weeks ago, the IDIOT must have looked at the wrong part # or something or they decided to jack the price up for more $$$$$
uuuuuuuuuuuuuhhhhhhhhhhhggggggggggggggggg!!

this just ruined my day!!!!!

(feeling like the statue today)

------------------
92EB
Some days you get to be the Statue,
Some days you get to be the Pigeon!!

 

[KyleC]

Well, I guess $127 ain't too bad then......

Why is this thing so expensive anyway? There isn't a whole lot to it.