cheers knightrous, like the user name too :D
so its throws a fault flag, but its not doing anything else? ie cutting fuel or adjusting advance?
cheers knightrous, like the user name too :D
so its throws a fault flag, but its not doing anything else? ie cutting fuel or adjusting advance?
From my understanding there are no other failsafes for if the ignitor (Ie; no fuel cut etc etc), unlike the AFM which will cut the fuel pump if it detects no flow.
great info :)
im presuming that as the revs are beening dropped to a preset value the fuel will be set to that rpm?
i dont know if the tps or the map sensor is used along with rpms for the reference value in the fuel map (my car doesnt have an afm, mk1b 1989)
i suppose either in a launch control condition should richen the fuel
tps at fully open is a large load signal make the ecu increase the fuel
map will see less vacuum at wot and the ecu will think engine load signal too and increase the fuel
if the ignition signal only shows a flag, the advance shouldnt change (phew!)
but the wot condition with limited rpm, will show the same high engine load conditions to the ecu when it looks up the ignition value map position
which could cause a change in advance, bugger...
i think i need to get the scope wired onto the ignitor, and see how the signals change when the launch control cuts in
i cut my teeth on celica ecus which can be a pain in the ass, i dont know if the mk1b mr2 ecu is anywhere near as clever
IIRC, fuel is done on the map with RPM VS MAP.Originally Posted by semtexcow
It must have had an engine swap? Bigports before 86 were MAP and after 86 were AFM.
The ignition map should be like the fuel map, RPM VS MAP. You will get different MAP values at the same RPM depending on the load.
I don't think you even need to worry about it ignition advance when in launch conditions. When the spark is cut, if the ECU panics over the lack of ignitor signal, even if it changes the advance, it's not like your driving under load at the time. The ecu will correct the advance the moment it comes off launch (When it gets ignitor signal back, that's if it even changes the advance).
My mk1 came from the factory with a map sensor 4a (ye olde bluetop) when it was built in '87. Which is one of the reasons I owned it - I prefer the bluetop to the redtop.
My dad's '88 has a MAP sensored redtop in it, again original factory fitted engine.
I'd be tempted to check what the ignition timing & injector pulsewidths were doing while the launch is active, just to see if it's advanced / retarded or rich / lean from where it would be with the launch disengaged. Or rig a delay (fraction of a second) so the nitrous doesn't come in until the engine's recovered from the launch.
It's a 2.0 inline four that thinks it's a viper v10. What's not to love?
thats another thing, how quickly does it recover?
the warning light is on for 1-2seconds after the launch control is dropped
Interesting, all the Aussie released (ADM, not JDM) 87-89's I have seen have been AFM. Are your cars UK release (UKDM?) or JDM imports?
Anyway, that's off topic :P
mines a uk model :)
Hmmm.
Random thought, what happens if ya fire in some extra fuel using the nitrous system fuel 'noid, with the engine running normally?
Should at least tell you if it's possible to throw a check engine light due to overfuelling, and if it does come on it'd be interesting to see how long it takes to switch itself off again.
4A ecu is dumb as a post. Wondering if it's trying to fuel for full throttle acceleration, reading rich as hell due to cut sparks and the o2 sensor (not the most accurate or fastest reading in the world) is taking a second or two to catch up once you disengage launch. Launch control on my ECU ignores the o2 sensor while engaged to stop the o2 sensor interfering with fuelling changes from fuel or spark cuts.
It's a 2.0 inline four that thinks it's a viper v10. What's not to love?
id imagine if the the throttle is wide open the ecu should be in open loop anyway?
where exactly is the o2 positioned? cuz i had a quick ness this afternoon and didnt see one
was only a quick shufty though
all answer tomorrow, will have all the new toys wired in and ready for testing
just need to fill an 11lb bottle up and ill do some testing :)
Posting Permissions
Reply With Quote