Blacktops when cold

[[A NINJA]]

My BT carib went to the dianostics @ miles toyota in chch.

it came up with error 25 (the O2 sensor)

my car struggles with 3-4k rpm until 20mins into driving (even after a 5 min warm up)

they quoted me almost $500 to replace the part and they said it would be ex japan.

My question is..... how bad is it for your engine to run around with a poked O2 sensor?

[Caribeena]

you added a catch can at all? mine used to stutter around the same rpm, but since adding one it hasnt...

also is it pokedf? or in need of a clean? try following the steps on this ..
http://forums.toyspeed.org.nz/viewtopic.php?t=60056&highlight=fuel+economy

[Matty104]

mine is screwd aswell, getting a new one from mr revhead for $250 delivered, easy as to put in aswell, no need for mechanic, all youll need is a jack and a spanner

[78ke30]

has any one tried looking at there ecu

http://forums.toyspeed.org.nz/viewtopic.php?p=601032#601032
http://www.toymods.net/forums/showthread.php?t=27814

may be worth a look

[78ke30]

has any one tried looking at their ecu

http://forums.toyspeed.org.nz/viewtopic.php?p=601032#601032
http://www.toymods.net/forums/showthread.php?t=27814

may be worth a look

[DocT]

OK people, I changed my fuel pump on the weekend.....wow...what a difference. I have been through all the various ideas people have come up with no real fix...yeah the new o2 sensor made it feel better for a while but soon started hesitating again. The new (80km) pump has made the hesitation disappear and the car feels real strong. I was reading this site http://www.asashop.org/autoinc/jan98/techtotech.htm and thought ...maybe. Picked up a pump off TM for $50. Anyway...no guarantees it will fix yours but it has fixed mine. Beware...wreckers want the earth for secondhand pumps!

[Cakky]

mechanic replaced my fuel filter also reset the timing and fiddled with it a bit, hasn't had the flatspot since...

[AE25]

a workmate of mine recently bought a '96 ae111 bzg which he has recently come to me asking why it hesitates when cold.. which is why i've visited this thread. his car has a pod and fart cannon and the engine also backfires out the exhaust on decelleration which makes me think its running rich.
upon reading thru this thread there is obviously a few different ideas floating around which helps some engines and not others. this is a rather large post to read thru so i thought i'd sum it up.
apart from a few maintenance issues like blocked fuel filter, dead fuel pump, frayed MAP vacuum line etc...
the two main reasons are:

1: oil vapour from cam cover via pcv valve and cam breather clogs inlet up.. cleaning the throttles can fix it. oil vapour may cause detonation on a cold engine which the ecu may react accordingly to?
2: oxygen sensor giving false readings or not working at all. replacement usually helps but can return after many k's of use.. especially if engine running rich or burning oil.

what i'd like to know is.. what is actually happening when the throttles are dirty?
Is it that there is less airflow at part throttle past the butterflies that the tps is no longer giving correct readings. i hear that tuning at part throttle on quads can be tricky on aftermarket ecu using turbo. could be a sensitive area of the map that requires acurate tps and map readings? i somehow doubt this as this hesitation you guys speak of is not at a set throttle position.. but at a certain rpm.

Or could it be the little air ports in the BT throttle manifold get blocked and gives reduced, delayed or no vacuum to the MAP sensor? i would think that isolating the cam breathers from the inlet and cleaning the map air ports out, should solve the problem if this is the reason. this should also help keep the oxy sensor free of carbon (by using oil catch can) and stop any oil related detonation from happening.

i'd suggest also that don't always nana the car.. drive the car hard once in a while.. you might find the oxy sensor works better afterwards.
what you guys think?