[MR2] MK1 ECU quesiton

[Aaron Willis]

Surprisingly, it's not really that dumb, and it can and will recalibrate
the fuel table based on feedback during closed loop operation.  This is
based on the fact that I've used it with two different sized injectors,
two different sized AFMs, three different camshaft combinations (plus
scores of cam timing setups), and a small handful of header and exhaust
systems.  As the configurations veer further from stock, it'll run
rougher and take more time to relearn after being reset, but after a few
hours of driving it always finds a nice groove and makes itself work.

The only caveat here is that I never had a way to monitor open loop A/F
ratios while on the stock ECU, so I'm only assuming that they worked out
well based on the fact that it always ran strong under open loop after
it had time to relearn its closed loop table.  I'm assuming it also
retrimmed its open loop table based on what the engine wanted during
closed loop.

Of course, since there is no feedback on the spark table (except
smallports and SCs), it can't relearn or retrim ignition advance.  (If
it had that ability I probably never would have bothered with
MegaSquirt!)

Basically, though, unless you mess with your engine in a way that
changes its fuelling requirements, you shouldn't have to reset it
periodically...if that's why you're asking.


On Thu, 27 Sep 2007 21:37:41 -0500, "Donald Chalfant"
<dkchal at datasync.com> said:
> AFAIK, the MKI ECU is dumber than dirt.
> ----- Original Message ----- 
> From: "John Treadwell" <DBSS_Gohan at hotmail.com>
> To: <mr2 at mr2.com>
> Sent: Thursday, September 27, 2007 9:00 PM
> Subject: [MR2] MK1 ECU quesiton
> 
> 
> > Hey, quick question on MK1 ECUs, Is there ever any learning, or any
> > resetting you may need to do? Any recalibration? I'm basicly asking how it
> > works? It's technicly not an OBD system, right?
> >
> > --John
-- 
Aaron Willis
'85 AW11 7A-GE hybrid
'77 TE51 3T/2T-G project
Club discount on genuine Toyota parts! email me: awillis at lithia.com