Ecu reset procedure.....

[Kaz-kzukNA1]

OT and just curious: what is the red symbol in the lower center of the instrument panel. I haven't seen this before.

Mine is JDM so different from European spec.
The beep and that indicator immediately after IGSW P2 ON are the seat belt reminder.
Introduced from Nov/92 model in Japan.


Kaz

[britlude]

right.. latest investigation results....... when i got home from work the idle was about 1000, with the occasional rise and drop, not as bad as the previous vid... with it running i did douse anything that could have a vac leak with carb cleaner hoping to get a reaction, alas no, so disconnected the ECAV to see what happens.... idle nice and stable, adjustable with the idle screw....



if you multiply the Hz on the multimeter by 20 you get the rpm.... so i can wind it down to 37hz or 740rpm and no lower. i would expect the engine to be able to stall on the screw.... i did block the pcv valve, and it dropped a little to 660rpm, ..... but rose with the pcv valve released again,so some air getting in there as expected...

so no obvious leaks, so it could be the fast idle valve not closing completely, which is a possibility, or the ECAV leaking a little air past...

reconnecting the ECAV valve, the ecu controls the engine speed, the idle lifting again to about 1000rpm, so that is doing something. if i alter the idle air screw (so many idle air circuits!!) the ECAV tweaks to keep the revs about the same regardless of whether the screw is closed or not, but with the occasional rise and fall....

a little percussive maintenance on the ECAV (ie. tap it with a metal stick!) and it seems to be a little happier, so suspect that might be being a little sticky too, given the soot that was on the idle screw when it came out, i wouldn't be surprised!

so, to that end, i have a new fast idle valve, new ECAV, AIT sensor and pcv valve from Amayama, along with a full intake gasket set, so it'll get removed, cleaned, internal butterfly screws checked and all put back together!



as it stands at the moment, restarts like this..... with gear selection too....



so, better, we'll see how it behaves for the rest of the week!

i shall put a new idle screw in too, just to complete the intake set! just got to find one that's not on a silly lead time! (16016-PM6-005... same as a del sol!!!)

[britlude]

Idle screw should be with me Saturday!!!

[sorepaws]

Thats the problem with idle screws, they are never in a hurry !

[britlude]

Ba-dum tish!

[britlude]

i might have a breakthrough with the idle issue.....

i recorded this today, the TPS signal at the transmission computer....



now, i'm not doing anything, but the signal is unstable... and the engine revs are following the signal, rev rising when the signal drops low...at least i know whats triggering the rev changes.....

the TPS signal only goes to 3 places- the engine ECU, the gearbox ECU and the traction control computer.....


so disconnect the gearbox and traction ecus.... start up and see what happens?...... (you don't need to watch all of it....!)



somewhat more stable, just a bit of noise, but nothing unexpected, cars are electrically noisy places......

[britlude]

plug the gearbox ecu back in.....



well that's a whole lot better, doing just what it's supposed to......


fortunately i have a spares, so next step is to add in my spare traction control ecu....... (and find out that AJ and Kiki are safe, phew)





so i might be a whole lot closer than i was... i suspect i was getting false leads as anything i did to the gearbox ecu involved unplugging the traction control computer to get to the gearbox connectors.... not counting my chickens, yet, i've been here before, but does look promising

seems the traction control computer may have been corrupting the TPS signal... i shall swap in the tps computer proper at the weekend once it's proved itself and investigate the 'problem' one!