Bluetop O2 sensor question

[rollaholic]

hi all,

the bluetop in my AE85 has no O2 sensor in the exhaust currently. i've been ringing round a few places trying to sort something out, and at the moment the cheapest option is looking like a universal aftermarket one.

what im hoping someone can tell me is, what kind of sensor do i need? the parts guy was saying the listings for AE92 onwards 4As were all the same, is that same sensor going to work on my bluetop?

secondly, can someone tell / show me where its supposed to wire into the loom? i didnt do the engine conversion (just got the car a week ago) and while it seems to have a complete loom, im not really sure where it should be connected.

cheers!

[big_boy]

it might not need one as it might be a NZ new motor have you thort of that

[rollaholic]

no, i hadnt thought of that. i didnt even know NZ new engines didnt use o2 sensors... guess you learn something every day.

guess i better get my TB sorted out and see how it goes - been having problems with idle.

[2LTR Rona]

not an issue with a hunting idle or really high idle is it ?

my bluetop had that issue, replaced the bypass valve under the throttle body, as someone thought it was a wise idea to stuff it full of paper, due to it being naffed, sourced it new from Mr Revhead, better result straight away.

I still think I have a vacuum leak to sort though

[rollaholic]

well, i was just reading bluemaumaus thread a few down, and i think i need to try a few of the things mentioned there. the coolant pipes are currently disconnected because the tubing was leaking, but i got that repaired today so i'll get it back together and see how it goes - but yes, it surges from about 1500 to about 2200 at idle consistently - makes it a dog in traffic, and a gas guzzler on top of that.

[2LTR Rona]

yeah start with the coolant pipes.

mine was like that....nothing like pulling 2500 while sitting at the lights going nowhere

[big_boy]

NZ motors dont have an O2 sensour because our fuel has/had so much lead going by what your saying im thinking

bypass valve or AC idle up valve also posably dirty TPS

[Stealer Of Souls]

According to my toyota ae86 workshop manual..
Bluetops don't actually use the O2 sensor for anything.

[l1ttle_d3vil]

you can easily pick up 2nd hand o2 sensors off any bluetop 4ages, theres a few on trademe every so often for pretty cheap. don't need to go with anything aftermarket.

thats if you need one at all though, i havent heard of 4ages not having them but doesnt mean the others are wrong.

if you do need one, your car will most likely just run richer than it should. do you have a small yellow round 1 pin plug on your loom? should be by the distributor, if you do thats for yoru 02 sensor.

[Ae92typeX]

cant be too much $ at pick a part. then again, cannot be sure they are working.
As above, nz didnt have, jap bluetop did. Perhaps (if can) find out if runing a nz new or import loom/ecu?

[l1ttle_d3vil]

Perhaps find out if runing a nz new or import loom/ecu?

you should be able to do that by a) checking if there is the plug I mentioned above on his current loom and b) taking the cover off the ecu and checking if there is an "OX" pin on it, as thats the one for the o2 sensor.

[Mr Revhead]

or post the ecu number and il check it

[2LTR Rona]

if you do need one, your car will most likely just run richer than it should. do you have a small yellow round 1 pin plug on your loom? should be by the distributor, if you do thats for your 02 sensor.

Hmmm that probably explains the richness of mine (someone else did conversion)

You are in fact speaking of this little yellow plug in question arent you ? (see pic)

[crispy'86]

According to my toyota ae86 workshop manual..
Bluetops don't actually use the O2 sensor for anything.

If the manual is for an nz model then it wouldn't. Imports still need the O2 sensor for fuel trimming when it runs in closed loop mode, or when the engine's at normal operating temp and uses the O2 sensor for an input to the ecu for fuel trimming,

[l1ttle_d3vil]

Hmmm that probably explains the richness of mine (someone else did conversion)
You are in fact speaking of this little yellow plug in question arent you ? (see pic)

only yellow plug i can see in there looks like its the distributor plug - thats the 3pin/wire plug (think the wires are red black and white). the O2 sensor plug has just a single white (IIRC) wire going to it. it sits on the loom between the distributor and coil plugs, unless its been modified obviously.

[matt dunn]

A single wire oxgen sensor is useless and not even worth worring about.

If that's what your car is meant to have, dont worry about it.

A three wire one is important,

and some 4 wire ones are critical to running.

And that doesn't mean you can fit a 3 wire in place of a single wire,
as the efect it has is dependant on what the ECU is programmed to look for. Even if you fit a 3 wire so it works from almost cold, the ecu still wont worry about the signal as it's programmed not too.

The only time a single wire sensor has any effect is at normal operating temp and at cruise only.
They have no effect on cold running starting, or engine power,
as they dont work when cold without a heater, and at WOT the ecu ignores thge signal.

Crusing at 100kmh, they may save you 10c per 50L of gas.

[rollaholic]

thanks for all the feedback folks.

its certainly been a learning experience owning this car... its only been 2 weeks, but im loving it. put the heat piping along the side of the block back on today after getting it back from repairs, which of course feeds the throttle body thermo valve thingee... this has largely cured my surging idle as i'd hoped, however idle is still high.

timing check revealed 15 degrees advance, which i believe has been dialled in to attempt to compensate for the cam timing being out by a tooth perhaps - the cambelt was also exceptionally loose when i got the car.

on another note, this lovely example of an engine conversion has a fuel pump in the engine bay - presumably because it used to be home to a carb fed engine, and has no fittings for one in the tank.

i'd like to move it back to the boot at least, i see people talking about VL commodore fuel pumps being good value - are they external pumps, or in tank ones? im considering my options in terms of engines, but defintely more power is in the future, so something that will stand up to moderate power increases would be nice too.

[l1ttle_d3vil]

im running a vl commoodore pump on my ke35 / 4age, externally mounted just below the fuel tank. before that it came off a ke35 / 4agte and never had any issues at all, so plenty of room for movement power-wise.

hgave you checked the idle screw? that might be wound out quite a bit? also with the timing like that it could be causing the high idle too, reset the timing yourself (both cam and spark) so you know 100% that its correct. when the timing was wrong on mine it was idling higher than it shouldve been...
don't forget to put it in diagnostics mode when setting the timing though

[rollaholic]

yeah, the cam timing is right, checked it this afternoon after work - dunno how to put the engine into diagnostics mode though, time to do a search me thinks. i did wind the idle screw down a little, it wasnt massively wound up though.

[rollaholic]

alright, i did a search and i think i found the info i need to put the engine into diagnostic mode - is the plug i need to bridge one of these bad boys?

http://i29.photobucket.com/albums/c296/ ... nostic.jpg

the two in the middle are both two pin, but im assuming its the round one... and the procedure is to connect the two pins, get the car warm, make sure the throttle body is closed, then set the timing with a timing light and dizzy cap adjustments as you would for a carby engine?