black soot on my bumper?

[ae71 kid]

my 1jz mx83 gets 12.5 l/100km on a highway and 16-20 l/100km around town depending how hard i drive it.. it manual and it also develops the black crap over the rear bar but only if im during around town driving (i assume its cos it get 2 cold starts per day followed by a 15 min drive so it barely gets warm)

[Officer Doofy]

[QUOTE=
370km per tank on 1J not necessary poor economy[/QUOTE]

Lol 20l/100klm isnt poor economy riiiight

Check you ecu for codes, I too was recently getting the same economy and had a code 25.

Two easy fixes to try is a new oxygen sensor and new ecu temp sensor. I recently changed my oxygen sensor and now see 10lt/100klm on the highway and 12-15lt/100klm around town depending on the right foot.

[The Last Streetfighter]

Also worth checking ECU for leaky capacitors.

[Endless]

how does the mechanic plan on tuning the stock ecu which controls the timing etc?
if theres a way to do it post it up here.

Exactly what i was thinking..

[suss_slide]

sorry i meant to say hook up the map sensor and o2 sensor and see what there doing, which i assume he did. As it turns out my o2 sensor is a bit tempermental and i have an exhaust leak, Good news is im running a healthy 168kw ! not too bad from a stock 1j!

[lt1972]

Officer Doofy,
lol, I was comparing it to my old ute.....36L/100km as a joke, so in that context its good fuel economy