[Gmecm] Hard Starting

[Jared Ryan]

I just need a starting point for this.  I need a good guess at which 
way to go to correct this problem.

This engine "catches" *fast* on a cold start.  I just turn the key, and 
after a few revolutions it's running.  It smoothes out, and the ECM 
gradually reduces the idle speed.  No problem.

On a hot start, it usually won't catch.  It cranks very fast, but just 
doesn't catch.  However, if I hold my foot down all the way on the 
accelerator pedal, it will always catch after several seconds of 
cranking.  It's just like if I was trying to clear a flooded engine and 
I open the throttle all the way on a carburetor.  When it does catch 
after doing this, there is a puff of black smoke from the tailpipes.  
Once it catches, it idles smoothly and there is no problem keeping it 
running.

So... I have the programmer and TunerCat and WinALDL... what should I 
alter to make the hot starts easier?  Is there anything I can analyze 
with WinALDL that would tell us?  I call this a hot start problem, not 
an idle problem (again, once running, it's very stable and relatively 
smooth).

My impression - based on having to open the throttle and that black 
smoke comes out when it catches - is that it's too rich on hot starts, 
but maybe it is too lean and I am adding fuel by opening the throttle.  
I don't really know how the ECM "thinks" at start-up.

Any thoughts are appreciated!

Engine: New GM long block 350, 9.2:1 compression, Crane 2032 camshaft, 
.214? int., .220? exh. @ .050" lift.

Injection system: Rochester TBI, unmodified throttle body, 65 lb./hr. 
injectors, Edelbrock 3704 intake manifold, 14 psi fuel pressure 
measured before the filter.

ECM: 1228746, ANLU .bin (1989 Chevrolet Caprice 9C1 Police calibration)

  ---> Jared Ryan <---
jryan at caminofx.org | http://www.caminofx.org