Air/fuel gauge

[OLD_SupraRob]

hey everyone.

Been attempting to fit a air/fuel gauge to my supra but a bit lost as where to take the signal from???

Anyone have any ideas??? im assuming i need to pick it up somewhere near the ecu but im lost as to wich wire to use. ive searched the internet and forums but i have not come up with anything as of yet.

Im a bit desperate to get this done as the car comes off the road next week for some engine work and i want to monitor it before and after.

Any help greatly appreciated.

Rob

By the way the supra in question is a 94 jap spec n/a

[Martin F]

Quote[/b] (SupraRob @ Dec. 26 2005,18:52)]By the way the supra in question is a 94 jap spec n/a
Yeah, but what sort of gauge is it http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/tounge.gif


Does it not have it's own sensor ?

[OLD_SupraRob]

no sorry it uses the stock sensors.

Ive had the gauge working by running a cable round into the engine bay and connecting it there but i would rather the conection in the car somewhere

[Martin F]

Try splicing into pin B-48 on the ECU, as shown here:

[Martin F]

More info.

http://www.mkiv.com/manual/1995_electrical_manual/I/95elec_087.JPG

[OLD_SupraRob]

Thanks for the info martin, thats very helpful. i will take a look at it again.
Correct me if i am wrong but is pin 48 the white wire?http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/rock.gif next to the 2 wires with transparent insulation

i was looking before trying to trace the wire but i had to give up when i lost daylight.

[Martin F]

Yep, it is a white wire.

[OLD_SupraRob]

Brilliant. Thanks for your help martin.

i had a feeling that was the wire when i was looking at it yesterday but didnt want to go cutting into any wires until i had got some advice from someone with a bit of experience.

Once again thanks for the help, will keep posted with the progress.

[slick]

Quote[/b] (SupraRob @ Dec. 27 2005,10:18)]i was looking at it yesterday but didnt want to go cutting into any wires until i had got some advice from someone with a bit of experience.
Or theres always the old 'cut it and see if something stops working' approach.... oh thats just me then ?http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/tounge.gif

http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/outahere.gif

[Martin F]

Best way to splice into it would be to strip back some of the insulation with a sharp knife (about 1cm), strip about 1cm of the insulation back from the end of the wire on your gauge and then wrap the two together and solder them. Then insulate with a good quality electrical tape.

That way you don't break the integrity of the existing conductor.

If you come back and tell me you've used a blue or red Scotchlok then i'l personally come over there and introduce you to a soldering iron http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/wow.gif

[OLD_SupraRob]

hahaha no scotchlocks here martin, i can honestly say i would never own the evil little things.

all done and workin fine now.

Thanks again for the help.

[GavinL]

Quote[/b] (SupraRob @ Dec. 26 2005,18:52)]Im a bit desperate to get this done as the car comes off the road next week for some engine work and i want to monitor it before and after.
It's not going to tell you ?much, just Rich - 14.7 - Lean conditions.


What were you trying to monitor?

[OLD_SupraRob]

exactly the above mate, just wanted to know if it was running rich or lean at different points so i could monitor it again after the engine work to see what difference it has made.

[chriscollie]

Gents,

Sorry to ask - 'Scotch Lock': what are these? are they the connectors that u cut a wire, enter it into 1 side of the connector and screw it down, then do the same for the other wire and the signal flows through?!

As you can tell, not quick that up to speed on connectors!!! ha

Chris

[Martin F]

Scotchloks are those little plastic clamps with a metal splice inside that you clamp round an existing wire and a new one and these join them together.

If you look in this thread http://www.mkivsupra.co.uk/cgi-bin....;t=4456 (http://www.mkivsupra.co.uk/cgi-bin/iB/ikonboard.cgi?act=ST;f=16;t=4456) you can see a red one and a blue one in Flynn's picture.

In theory they are a fair idea, in practice they are never matched to the right gauge wire and even when they are contact is a bit hit and miss. Then introduce temperature and humidity and you have a sure fire winner for intermittant connection.

Avoid like the plague !

[chriscollie]

Ah ha!!

I see, i posted a topic about my trac off lamp flashing a wee while back and was told to look at the speedo conversion - i took off the dash and if i remeber rightly, im sure scotch loks were used there??

If it is, should i remove them and connect the wires some other way etc?

Chris

[Martin F]

Yes, most defenitely. Invest in a soldering iron and some solder, shouldn't cost much more than about ?20. If you've never soldered before then practice on some spare wire.

If you feel soldering is beyond you then the next best thing is some crimps and a crimp gun.

[chriscollie]

Yeah, i have soldered before but it was a while ago!!

I read the post about the trac on/off article and that cold joints can be the source of problems etc and i had my trac on/off light flashing so i'll do that at the same time as i have the dash off - it talks about Rosin solder etc? i take ot i will get all that from local eletrical supplier?

Oh well, looks like my next few days off work will be spent re learning to solder!! ha ha,

Cheers for the help- i'll post any progress!!

Chris