Please post

[Joe Boucher]

At 01:22 PM 6/27/97 +0100, you wrote:
>	The LPG fuel systems usually retro-fitted to vehicles are
>totally independent of the gasoline systems., ie the gasoline ECU has
>nothing to do with the LPG fuel metering.
>> ----------
>> From: 	boughton at bignet.net[SMTP:boughton at bignet.net] on behalf
>> of James Boughton[SMTP:boughton at bignet.net]
>> Sent: 	26 June 1997 23:52
>> To: 	'diy_efi at coulomb.eng.ohio-state.edu'
>> Subject: 	RE: Please post
>> 
>> Michel,
>> 	Here is my guess (and believe me I am guessing).  On typical
>> gasoline injection cars there is a function which decreases the
>> pulsewidth for a short period of time on open to closed throttle
>> transitions.  This is to keep the engine operation near stoichiometric
>> while the puddled fuel in the intake manifold gets sucked into the
>> engine.  With the LPG fuel there is no puddling and the decrease in
>> pulsewidth is actually forcing the engine lean causing the bump your
>> friend is feeling.  As I am not familiar with the control system of
>> the 730i or LPG fuel I am shooting in the dark, but there is my
>> explanation :-)
>> 
>>

Here's another thought.  If this system was a hack job, did they put in a
O2 sensor adapter.  Propane stociometric (SP?) is around 15.5.  If the O2
sensor is sending back a standard signal and the computer thinks its using
gasoline and tries to maintain 14.7 and it should be 15.5, maybe that's
part of the problem.

And that is a guess also.

Joe Boucher
70 RS/SS Camaro   81 TBI Suburban
Bedford, TX