Are your DIC fuel economy calculations accurate. My MPG's are higher than they actually are and that is because I DIC thinks I have used more fuel than I have. I guess this means that the computer cannot accuratly gauge how much fuel it is putting in.

I was thinking that this may be due to the fact that something else may be putting fuel into the system besides the injectors, ie maybe a broken fuel pressure regulator that is spitting fuel into the vacuum line which eventually ends up in the engine. The engine computer could compensate for this and most of the time the engine would run fine, however the DIC would have no idea this fuel is going in.

I dunno, just curious if anyone elses is accurate. Last I checked I did 400 miles and I actually used about 15.4 gallons yielding me a mpg of 25.9. But the computer thought I had only used ~13.8 and it told me my average mpg was around 29. Do you guys think its possible that if my mystery source of fuel is the FPR that it could have leaked 1.6 gallons after 400 miles or about 6 hours of driving?

The DIC on my '98 is usually between 1/2 and 4/5 of a gallon shy of what I really use (i.e. it tells me I've used 15.2 gallons, I put 16 in). I've noticed about the same with my mother-in-law's '98. So, there's a bit of a discrepancy there in your case. Might try disconnecting the negative terminal on your battery for 30 minutes or so to reset everything, then fill 'er up and test. Are you getting hard (crank for 4-5 seconds) starts? If not, I highly doubt it's the FPR. What year is your Aurora? You don't have one of the the earlier models with the fuel line leaks, do you? A good visual inspection of the fuel lines is in order. Changed your fuel filter lately?

--Robert

I have a 95, but it already had the fuel lines break and they were replaced. It takes a couple of seconds to start but not what I would consider a long time. The reason I'm thinking about the FPR though is becasue I do notice some slight surging when driving. I'm going to check it out when I get a chance. Does anyone have the partnumber for the 95 FPR?

I have a new fuel filter just haven't put it in yet.

I was reading some post on a cadillac website, they were suggesting that the thing should be pretty damn accurate, and if its not it is because fuel is getting in without the computer knowing it. Possible reasons, leaky injector, bad FPR, maybe even incorrect fuel pressure, but I guess that would fall under the category of bad FPR but could be related to fuel pump/filter.