Not the normal MPG thread. need some insight and opinions here!

[djsk8r33]

ive been waiting a long time to post this until i fixed everything on the list and searched and searched.

got my X in december, ran okay. got crappier. almost wasnt running. recently i've fixed about everythign except my MPG.

full tuneup when i got it.
recently changed plugs because #3(ithink(rear pass side)) was fouled up.
air filter
fuel filter
IAC
cleaned MAF
oil changes
new inflated tires
new brakes
(brakes are not sticking either)
brand new cats witht the rest of the exhaust system

i had a severe coolant leak, it was an itake gasket, but the barrs stop leak patched it up (so far, so good knock on wood!)
either way tha should not be affected gas milage.

ive been getting solid 10MPG since i got it. this leaves me to believe it something totally diffferent, but drastic. i have a little bit of a heavy foot but its not that bad. i should easily be up around 15, At least.

 

[Blacksheep Josh]

how's it idling? rough? smooth?

 

[kert0307]

O2 sensors?

 

[djsk8r33]

02 sensor is perfect
before it was idling crappy but now it is nice and smooth.

the one thing that fathoms me. i have a straight alignment but on highway speeds i get a vibration. its bearable and probably still safe,

 

[bluexpy]

If the 02 sensor has more 50k on it, replace it. YOu'll notice the difference instantly.

 

[aldive]

If the 02 sensor has more 50k on it, replace it. YOu'll notice the difference instantly.

Not unless it/they are malfunctioning. Way too many O2 sensors are needlessly replaced.

 

[djsk8r33]

If the 02 sensor has more 50k on it, replace it. YOu'll notice the difference instantly.

Not unless it/they are malfunctioning. Way too many O2 sensors are needlessly replaced.

you just saved me a pretty good rant, thanks al hahaha

 

[corkey]

what is the rear end gear code on the inside of the drivers door on the tag ??
just post the axle code,, that can be a difference,, lower gear,, less mpg,
any check engine light action ?
plug wires ?
has it improved since it got warmer out , and warm up time is it shorter ?
got a big sound system straining the alternator ?

,

 

[djsk8r33]

used to warm the truck in the morning for a while, but i have been driving more since its nicer. it sorta evens up

im pretty sure i have 3.55's in the rear. my code was 45 IIRC

check engine light gone. spark plugs/wires are brandy new

i dont have a big system (actually my subs are sitting there without an amp so they arent even on) i have a few neons and whatnot but i shoudlnt be straiining the Alt.
-how would that affect MPG

 

[Texan01]

I got news for you, Bars is very good at sealing coolant leaks, but also for plugging stuff up that doesn't need it, ie heater cores, coolant passages in the engine, coating vital engine sensors, etc.

Anyway, I think you have a coolant temp sensor (for the computer not the gauge) that is reading out of range.

The computer relies most heavily upon the operation of that sensor and if it's off, it will throw it's whole calculation off. Moreso than the O2 sensors (which are important as well)

I'd replace it. you can test it but to really test it you need to remove it and put it in a pot of water with the plug end out of the water and read what it says at known temperatures.

They cost about 10-15 bucks last time I bought one and take a few minutes to replace.

 

[djsk8r33]

I got news for you, Bars is very good at sealing coolant leaks, but also for plugging stuff up that doesn't need it, ie heater cores, coolant passages in the engine, coating vital engine sensors, etc.

Anyway, I think you have a coolant temp sensor (for the computer not the gauge) that is reading out of range.

The computer relies most heavily upon the operation of that sensor and if it's off, it will throw it's whole calculation off. Moreso than the O2 sensors (which are important as well)

I'd replace it. you can test it but to really test it you need to remove it and put it in a pot of water with the plug end out of the water and read what it says at known temperatures.

They cost about 10-15 bucks last time I bought one and take a few minutes to replace.

what the t-stat have to do with milage performance? are you refering to my engine telling me its normal, when its really over-heating.

yes i was told good things by known mechanics about barrs

 

[pogo]

if your t-stat isnt working properly and it takes the engine longer to get warm, it will take longer to go into closed loop and that will effect gas milage

 

[Alan_V]

What is your diriving pattern? Mostly city? Short trips? Our 93 4WDxlt only gets about 13 around town, less if my wife only takes it to work (3.5 miles). Get 17-18 on long trips.

My suggestion is to take it on a long drive and calculate your fuel economy then. If you get around 300 miles/tank, it's about the best you can do.

The one part that I've seen affect city economy most often is the t'stat. If it's stuck open, then the engine may never come up to temp and the PCM will run the mixture based on the input from the eng. coolant temp sensor. If that tells the PCM the engine is at 150, then there will be some added enrichment.

 

[pugsy]

Does the Overdrive work? That could kill mileage on the highway.
I consistently get around 22 MPG on the highway at 65ish mph.

 

[djsk8r33]

if your t-stat isnt working properly and it takes the engine longer to get warm, it will take longer to go into closed loop and that will effect gas milage

i am going to replace this and see what happens

What is your diriving pattern? Mostly city? Short trips? Our 93 4WDxlt only gets about 13 around town, less if my wife only takes it to work (3.5 miles). Get 17-18 on long trips.

My suggestion is to take it on a long drive and calculate your fuel economy then. If you get around 300 miles/tank, it's about the best you can do.

The one part that I've seen affect city economy most often is the t'stat. If it's stuck open, then the engine may never come up to temp and the PCM will run the mixture based on the input from the eng. coolant temp sensor. If that tells the PCM the engine is at 150, then there will be some added enrichment.

80/20 in favor of city drivings, id say. i've been on longer trips (60mi+++++ each way) and i dont recall getting better milage. at the time my truck wasnt running so amazing either. i have rusted cats and exahaust and half-a- tune up

Does the Overdrive work? That could kill mileage on the highway.
I consistently get around 22 MPG on the highway at 65ish mph.

OD works perfect