[V8] Re: cold weather killing gas mileage (AHA!!!)

[quickaudi at aol.com]

Well, the microfiche that I have says it is relay J208; which is right? (haven't been out to look yet.)  I know the fuse is good, but there might not be voltage.  Gotta check that as well.  
As for the ambient air temp affecting the gas mileage when the heater wires don't work, trust me, it does.  It's a good mile per gallon between 30 and 60 degrees, at least.  I don't know how, but it does.  
 
Joel
'90 V8q
'86 5kcstq
 
 


I looked at the 1991 wiring diagram last night.  The heater is powered
by what appears to be two relays in parallel ... one of them being the
fuel pump relay (J17 - Position 10).  There appears to be a 5A fuse S5
in line with the heater, you should be able to measure voltage there to
see if it is a supply problem.  

This morning I pulled up the soft copy I have ... looks like the pre-91
cars only used the single fuel pump relay.  Funny thing is I don't see
any way that the ECU can determine the status of the OXS heater from the
wiring ...