DIY_EFI Digest V4 #623

[Ned Williams]

> ------------------------------
>
> Date: Thu, 04 Nov 1999 12:01:09 EST
> From: "Derek Kaznoski" <sweetpea1998 at hotmail.com>
> Subject: Motronic ML4.1 newbie
>
> I have a '90 Alfa spider with Motronic 4.1.  The car has 62K miles and is in
> excellent condition.
> It will start after about 6-8 seconds of cranking, but will then just rush
> once or twice and quit if throttle not opened.  It will not idle.  It runs
> great above about 2000 rpm all the way to the redline without any power
> loss.
> While holding the rpm at between 1500-2000 (rough in this range), the check
> engine light flashed a 1223 code (lambda internal control).
> Over the past few months, I've had intermittent problems with low/rough idle
> (speed about 600 rpm) and stalling when taking off.  Other times there were
> no problems at all.
> I'm new to the auto repair game, so please assume that I don't know jack.
> Here's what I've checked/done so far:
> Air-flow meter resistances are OK with smooth flapper operation and
> resistance changes. I tried a spare AFM I have--no real change.
> Throttle switch is OK.
> Idle speed actuator gets battery voltage with ignition "on."
> Spark plugs OK.
> Tightened up all air intake connections.
> Replaced fuel filter.
> The battery is old and probably needs replaced--sometimes cranking is slow.
> I'm replacing it today. Can this cause a problem with idle?
> I haven't checked fuel pressure yet since I can't find a fuel pressure guage
> that is compatible with the car (only domestic Schrader valve types around
> here).  Any tips on where I can buy one?
> My shop manual says to "supply idle speed actuator with 12V directly for
> awhile and check for proper functioning."  Basically, I just plugged in the
> connector and turned the ignition to "on" with the bypass hose disconnected.
> I couldn't see anything happening inside the device.  I don't really know
> how this thing is supposed to function, though.  Can anyone enlighten me?
>
> Thanks in advance. Sorry for the wordiness.
>
> - -Derek Kaznoski
> '90 Alfa Spider
> -------------

Hey Derek,

Did you check the timing? that could screw with your RPM range and idle pretty
bad as well as the FI


Ned