[bog]

if mpg is off , then Close loop is not happening
if CL is dead.
you need to find why.
many reasons:
thermostat not getting to 180F min and holding
ECT lying its butt off. eg; water 180 ECT says -40f, or too low.
too high fuel pressure
injectors leaking
ecu injector wire grouned out and leaking injector.
ecu bad and turning on injector full time (12v on one side , 0 on other key on)
exh leak making 02 stick lean and AFR goes to MAX RICH.
a clogged injector
bad spark.
a dead cylinder.

im sure i missed something
ah , stolen gas. ( see it's me , sneaking away now., i never actually buy gas.....LOL)

 

[Bex]

Closed loop not happening due to stolen gas!!

 

[TheZuke!]

Oh, I think things are okay now, but the bad injector it had must have been stuck wide open to drop mpg so low. (and allow me to use the tailpipe as a flamethrower!)

Should I replace the Bosch Platinum plugs? Probably about 40K on them now.

 

[bog]

fur sure.......
if the gap is good and insulator tip looks spiffy (not contaminated), run it.

yes and the ECU has this little fault ( 02 related)
if one injector sticks on.
that cylinder misfire. (horribly)
each time it misfires, that cylinder sends a slug of oxygen to the 02. (intake, compression,no fire, no power stroke,,exhaust same as intake plus fuel O2+HC)
the 02 sees that, and sends a LEAN signal, to the ECU (1 slug of air is 20% Oxygen , 20% is HUGE to any 02 sensor)
the ECU then leans into the LEFT HOOK (and sends MORE FUEL) Stupid , huh? but real.

this is the profound weakness in all cars. and 02 sensors.

as you can see the stupid system ASSUMES that combustion is normal and only needs
at tweak. (reality is a cruel mistress)
and (not having x4 o2 sensors, dont help either)

 

[thirdgen92rs]

New here to this site, but I use it a lot for info, really good stuff on here. I have a 94 Geo tracker, 16v 1.6 with a 5spd manual, I had a bad misfire around 1 to 2 thousand rpm, turned out to be a spark plug. Now after I replaced it, it has either a high idle around 1000 to 2000, or a very low idle and stall. Not sure what this is? I have an exhaust leak, not sure how major haven't checked the manifold, but its lower past thecat. I unplugged the 02, no difference in how it ran. I unplugged the sensor on the intake tube (little black box with 3 pin connector) and it stopped the idling problems, bit ran extremely rick and constant at 1500 rpm. Scratching my head on this one, any advice? Thanks in advance

 

[Bex]

Welcome to the forum!! This is a 4 year old post, and you really need to start your own for any advice. Put your car specs into your signature as per this sticky:
http://www.suzuki-forums.com/suzuki...ick-escudo-vitara-geo-tracker/31042-attention-newbies-please-read-what-car.html
I'm assuming the little black box that you disconnected was your MAF sensor, which makes the ECU run on predetermined values (very rich, etc, but running). And an exhaust leak beyond the cat will not have any affect on the idle.
You should start with a compression test to verify the timing of the engine - all plugs out, well charged battery and floor the gas pedal when cranking for best compression. Post your results. Also confirm that your check engine light is on with the key on and off once the car starts.
Note that any vacuum leak before the MAF (which the MAF then 'sees') will cause the car to bog.....