poor milleage?

[tonyjklh]

what kind of mileage should i be getting out of truck? right now i am only getting max of 14 mpg highway. its horrible to know that my freinds chevy 1500 is getting more than my small mazda!! i dont know what could be causing the mileage, i have changed spark plugs, wires, airfilter, and oil. but still no differance.

 

[AllanD]

Replace your thermostat FIRST

get a 192'F (stock replacement) T-stat.

a 185'F T-stat will often cost you mileage if the ECT sensor is even
slightly out of calibration.

Replace the ECT (Engine coolant temp sensor, NOT the guage sensor) next
It may test as "good" on a code scan but that doesn't mean a whole bunch...

Many operation problems are not detectable by scanning for codes.
The thing is if a sensor is "almost right" the computer will compensate for an erroneous reading and compensate for a non exsistant issue then things really begin to suck.

THIS is why I went with a 1993 management system on my 4.0 swap,
because the 1993-94 EEC4 can display DIRECT readings of ALL the sensor
outputs and the HUMAN OPERATOR can decide if one of more of the
readings smells fishy...

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[tonyjklh]

i didnt know that that could make such a differance, i will probably change it begining of next week.

Replace your thermostat FIRST
THIS is why I went with a 1993 management system on my 4.0 swap,
because the 1993-94 EEC4 can display DIRECT readings of ALL the sensor
outputs and the HUMAN OPERATOR can decide if one of more of the
readings smells fishy...
AD

what kind of scanner do i need to get all these readings? my truck is a 94 so it should be able to get those readings right?

 

[AllanD]

Mine gets checked with a either a Ford "star tester" which was originally $1800
or a SnapOn Modis scanner which cost a friend the better part of $4grand with
ALL the stuff he got with it.

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[tonyjklh]

wow i think i will be skipping on the scanner then, thats a bit to much for me.
would be nice to have but not somthing i can afford.

 

[AllanD]

The simple "code scanners" that cost about $25
only tell you about the problems that the PCM has
already identified itself as problems and that is useful
and revealing of issues a disappointingly small percentage
of the time.

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