Where did my mileage go!

[ditchwitch1]

HI,I dont know where I went wrong,but anyway,when I 1st got my explorer eb,4.0,about 4 months ago,it was getting 18 mpg,and running bad,I figured out it was the fuel filter causing poor idle&running,in the interim of finding this out,I replaced plugs,wires,air filter,and seafoamed 2x.mileage jumped up to about 22,Now,a month later,I am down to 15.7 mpg{?}where did it go?what could I have possibly done wrong?The plugs I changed out were autolite platinums with about 40k on them,I put in ngk's[standard].It is running good,good power,not missing,just that the mileage SUCKS,at $3.00+ a gallon,this is a hard problem to ignore,I had read a previous post about winter formulated gas in northeast,would that make this much of a difference?what areas should i approach as suspect?Thank You,Kurt.

 

[JDraper]

Did you change the plugs before or after Seafoaming?

 

[aldive]

Have you cleaned the MAF? Have you tested the O2 sensors for function?

Good luck ....

 

[ditchwitch1]

Hi,Changed the plugs after seafoaming 1st time and before 2nd.I cleaned the mafs,and throttle plate w/sensor cleaner.Have not checked O2 sensors,Logical next step?Also I am noticing occasional idle surging .Changed IAC w/new,no real difference in idle quality.I checked for vacuum leaks,couldnt find any obvious,are there connections on 4.0 sohc that are difficult to see?Thanks for your help,Kurt.

 

[xdviper]

I'm thinking the O2 sensors, After a tune up, I've still got the Check engine light and I read the codes and its the O2 sensors. Still horrible millage. $3.11/G for 87OCT here in NYC.

 

[97greenmonster]

I would check the O2's and put a can of seafoam in the gastank. Do some mild mods to it to via intake exaust. my millage shot up. i get about 23 in the city with rpm only going to about 2200. im hopeing you didnt foul out the new plugs with the seafoam.

 

[ditchwitch1]

Hi,thanks for all the great advice!I am probably due for O2 sensors anyway,with over 154K on it now.And I was thinking of putting the platinums back in,they are still in very good shape.Its not setting check engine light{not even coming on},and it runs too darn good.How reliable is the economy guage anyway?sometimes it shows 14.2 mpg,and if I hit reset,it shoots to 90,and gradually drops down to around 18 to 19 mpg. I think I may have gotten spoiled as my last vehicle was a diesel p/u with a 30+ gallon tank,so I could go 2 or 3 weeks without filling,with the exploder,I can barely go a week.Thanks again.

 

[ThePhoenix]

whats is this seafoam stuff and where do I get it?

 

[Y2KFirehawk]

whats is this seafoam stuff and where do I get it?

http://www.seafoamsales.com/ and I know places like Advanced Auto and what not carry it...

This could be completely off the wall... but could it have to do with various gas stations switching to "winter mix" of gasoline combined with 02 sensors?

 

[ThePhoenix]

i am in Miami....so I dont think that affects me... but I too am having O2 sensor issues...and a miss at high RPM's

 

[aldive]

i am in Miami....so I dont think that affects me... but I too am having O2 sensor issues...and a miss at high RPM's

Have you scanned to determine the source of your issues?

 

[ditchwitch1]

Hi,seafoam is good stuff,originally designed for marine applications,hence the "sea"in it's name.Anyway,it is a multiuse powerful solvent,can be added to gas,engine oil,or as we are mentioning it here,running it through the intake system through a vacuum port.It gets in there and breaks up crud & gunk built up on valves and injectors,improving idle and performance,I am not a salesman for them,just someone who uses it and loves the stuff!Visit thier website for more info At...http://www.seafoamsales.com/ Anyway back to my running problem,no,I havent scanned for codes or sensor readings yet,hopefully my snap on guy will have his loaner modis back next week so I can borrow it and find out whats going on sensor-wise.I noticed today that it is surging at idle a little more{?}thanks for all the advice,Kurt.

 

[ThePhoenix]

my first mistake was taking it to Midas...who told me I had three oxygen sensors go bad....at once...so I got no info out of that. I have a freind with a code reader coming over this weekend. I want to love my truck, but with a miss in the engine....its hard to do

chaz

 

[ditchwitch1]

Changed the O2 sensors with new,mileage still stinks!Purchased an Actron obd 2 scanner today,is there any site that will help me interpret the readings I get?also has anybody used this scanner,and if so how do I get O2 readings?It is an actron autoscanner plus CP9180.I am at my wits end and ready to sell this beast! 98 eb,vin E 4x2 auto Thanks,Kurt.

 

[Y2KFirehawk]

Changed the O2 sensors with new,mileage still stinks!Purchased an Actron obd 2 scanner today,is there any site that will help me interpret the readings I get?also has anybody used this scanner,and if so how do I get O2 readings?It is an actron autoscanner plus CP9180.I am at my wits end and ready to sell this beast! 98 eb,vin E 4x2 auto Thanks,Kurt.

I stand corrected!

 

[ditchwitch1]

THis scanner shows live sensor data,such as coolant temp.and fuel trim,as well as air charge temp.and throttle position,all the good stuff,just at the o2 screen,it says not supported by vehicle manufacturer,I was wondering if someone has used one,and figured out how to do it.In any case,I am biting the bullet today,and taking it to a local shop to see if they can help.

 

[ditchwitch1]

Well,took it to the local shop today,no real help,described everything i have done so far,and his advice,and I am going to try it,is ignore the fuel economy computer,I am taping over it,and do it the old fashioned way,filling up,driving and then filling up again and seeing what kind of mileage I am really getting.I will keep you posted.

 

[aldive]

Have you not previously checked the mileage the old fashioned way?

 

[ditchwitch1]

No,I am an idiot,I figured if it had the computer for this,it has to be right,right?So anyway,I will give it a few days and see how it does.