Hi fellas

I have a problem. My truck is a '94 F-150 300 / E4OD /4.11. I normally get 14.5 mpg, give or take. I am now getting a little over 8 mpg. I didn't think a 300 could suck down the fuel that fast.

Truck starts and runs fine.

Air filter, fuel filter and plugs are good.

My engine has developed a lifter tick about a week or so ago. I don't know if that has anything to do with it.

What else can I check? What sensors would contribute to poor fuel mileage?

Thank you all very much. Thank God I finally got a job, but even though it's only 15 minutes away, my fuel mileage is eating away the paycheck.

- Bill

 

O2 senser/sensers can screw with mpg like that when they crap out. Also, if you have a bad intake valve, then it could be letting fuel in constantly, which would drop your mpg. I hope someone else can jump in with some more info. for ya Bill.

P.S. Check out my 95

 

PCV Valve, Plugs/Wires/Distributor Cap/Rotary Button.....Possibly sea-foam it....

-Wes

 

I want to add, Might try some injector cleaner, I like Lucas brand. Sometimes it helps some, sometimes it doesn't.

 

Bill i'd suggest you check out the o2 sensor. Do you have a check engine light on? I'd pull codes. I know my 91' get horrible gas mileage since the o2 sensor is in part of the exhaust that isn't connected to the engine. It eats the gas like its 1970 again.

 

Yeah, check the 02 sensor, scan it for codes as it might have a code but no CEL. Tick could be the start of a leak in the air injection manifold (if only ticks under power) also check for seriously, a muffler full of acorns or collapsed cat. Is it down on power? does the engine sound normal, exhaust sound normal or restricted?

When was the oil changed? Did you blow out the air filter, sometimes fine clay will clog it but not make it look too dirty.

 

Thanks guys.

The O2 sensor shouldn't be bad. I'll have to check it though. If it's bad how will I know?

 

Hello

The oil has been changed recently. The tick is there no matter what, at all RPM's, load or not

No CEL light.

Thanks!

 

check the injectors to make sure they are actuating like they should...you could have one that is leaking

 

Bill i'm sure the tick is just something it developed with high mileage. Unless its a collapsed lifter but i hear fords go around with ticking lifters all the time, actually nearly everyone i hear, thats how i know its a ford going by (i'm dead serious).

 

Hmm, not sure if its relevant. At around 250k miles, mine started to develop a little tick and a soft *huff* out the exhaust and wasn't running too smooth. Compression test showed numbers all over the board. Exhaust valves had worn into the head and I caught it in time. New exhaust valve seats, shim springs and a cleanup pass with a flycutter under $200 and took a day to whip the head off and another day back on. Mileage had dropped a bit as well but it was a pretty easy fix. Still going at just under 500k

 

Alright fellas you guys are helping me with my research here. I'm trying to figure out the best way to attack this.

I don't know how to test my injectors. If I bring my truck into the local shop, will they know how to do so?

My engine has about 230,000 miles also.

 

Run a compression check.
Examine your plugs while you're there.
At idle look for excessive blowby when you remove the oil filler cap.
(this also shows up by soaking the little filter in the air cleaner housing)
Borrow a fuel pressure tester and see if the numbers are in spec.
(test port is on the right rear just behind the intake manifold)
You could also have an intake manifold leak. On a cool engine spray some water down between the manifolds and the head, look for steam out the exhaust. I had an intake manifold gasket dry out, crack and leak.

 

Pull the codes Bill,You could have a wire off on your o2 sensor or sum such thing going on.Have you checked your tank and fuel lines for leaks? Usually an intake leak will lean it out,sucking air burning less gas.How is your idle,is it staying normal and fast idling when first cold started?You ain't got one of them little "stink bug" cars or a chebby caught in your air intake do ya???? lol.Seriously,pull the codes,then look for other stuff if nothing comes up.

 

You sure that you didnt get low quality gas? My milage in both the car and my truck have suffered grately in the last few weeks,maybe they are using the oil from the ocean to make the gas these days.....