CIS-E experts out there?

[Doug Yoder]

OK, let's recap:

Cold (open-loop) acceleration & idle problems (engine itself idles OK 
cold, but ISV duty cycle is way too high).  Car idles & accelerates fine 
when ECU runs closed-loop.  Both warm and cold idle are at correct RPM.

All sensors & wiring check out OK.
All vacuum hoses & connections check out OK.
Valve cover gasket & dipstick o-ring are OK.
Idle set screw is OK. (Problem occurs the least when screw tightened 
down 100%).
Static mixture is OK. (DPR current on spec)
Warm-up & cold-accel enrichment are OK. (DPR current on spec)
ECU and ISV have been replaced with known-good.
Fuel pressures are OK.
All timing marks line up at TDC, and ignition timing is spot-on.

So, next thing is to think about what else can change between cold 
engine and hot engine?
There is the mechanical stuff: pistons change shape slightly.  I don't 
see how that would be causing your problem though.

It would help if we could narrow the cold-acceleration hesitation down 
to fuel vs. spark.  Maybe hook your timing light up to each spark plug 
wire and see if the light keeps triggering as you open the throttle? 
Otherwise maybe kill the engine while it hesitates and see if the spark 
plugs are wet?  Maybe someone else has better ideas for determining if 
fuel or spark is the problem on a running engine.

Have you changed you fuel injectors recently (or at least checked spray 
pattern)?  Poor atomization of fuel could cause this problem... hot 
engine helps vaporize the fuel better.

-Doug

CTDiesel at aol.com wrote:
> According to your description on the engine timing, i have it
> correct...so that rules that out.....man we are running out of things
> that can be wrong.
> 
> Regarding the mixture if i set it to 0mA i hardly get a cold accel
> problem....but when warm i get a big hestitation until i get to
> 2000rpm then it takes off like a rocket.  The reading at the 02
> sensor with this setting is too rich i get .8v constant. Otherwise if
> i set it anywhere from 1-15 i get the same issues.
> 
> DJ
> 
> 
>