Please post

Andrew Rabbitt AERabbitt at rce.ricardo.com
Fri Jun 27 12:22:33 GMT 1997


	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 :-)
> 
> Jim Boughton
> boughton at bignet.net
> Owner - Boughton Engine Systems Technology (B.E.S.T.)
> 
> 	----------
> 	From: 	Mpotheau at aol.com[SMTP:Mpotheau at aol.com]
> 	Sent: 	Tuesday, June 24, 1997 6:16 AM
> 	To: 	DIY_EFI-Digest at coulomb.eng.ohio-state.edu
> 	Subject: 	Please post
> 
> 
> 	A non English speaking friend of mine is having problems with
> his BMW 730i.
> 	 The car is far, far away and I cannot reach out and touch it.
> I am not
> 	familiar with how the conversion was done, it has kindly been
> described as
> 	butcherwork.  The car runs on both LPG and Gasoline (one at a
> time).  The
> 	reason for this is obvious- cost of LPG is about 1/3 of
> gasoline.
> 
> 	Car runs fine on gas, no problems of note.  On LPG the car does
> not
> 	decelerate smoothly, sorta a reverse hesitation when lifting off
> the
> 	throttle.
> 	mpotheau at aol.com
> 	Michel Potheau
> 
> 
> 



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