[Gmecm] TBI 350

[Jared Ryan]

See, I ran it for a couple of days on the 40 lb./hr. 305 injectors, and 
it ran *horribly.*  It was painful to drive.  It didn't start easily, 
and it was clearly too lean while driving.  The 55 lb./hr. injectors 
helped it start much faster, and it just overall ran better.  A revised 
chip made it run almost perfectly - on 93-octane.

This all started when I decided to try to make it run on 87-octane and 
installed the adjustable regulator to try to richen the mixture some.  
Now, even with the regulator backed down to its lowest pressure, it 
idles very badly and still pings (though with the pressure turned up, 
it didn't ping).

The gauge should arrive tomorrow, so we can start working with real 
numbers and no guessing.

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

On Jul 13, 2006, at 1:29 PM, Robert W Hughes wrote:

>> Recently, I swapped engines.  The new one is a brand-new GM 350 with 
>> a Crane
>> Cams 2032 roller camshaft and high-swirl TBI heads.  The static 
>> compression
>> ratio is 9.2:1, and the dynamic compression ratio with that camshaft 
>> should be
>> about 8.7:1.  I changed the fuel injectors from the 40 lb./hr. units 
>> to 55
>> lb./hr. units like a 350-equipped half-ton pickup truck would have.
>
> You increased engine size by about 15% but injector size by almost 
> 40%. If you didn't change the injector constant, you might be running 
> up against the BLM/INT adjustment limits in the software. This would 
> mean that after the ecm leaned everything out as much as it could it 
> was still too rich. maybe.
>
> -- 
> Robert W. Hughes (Bob)
> BackYard Engineering
> 29:40.237N, 95:28.726W or perhaps 30:55.265N, 95:20.590W
> Houston, Texas "The city with too much Oxygen"
> rwhughe at oplink.net
>
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