This is too funny- I asked some questions on this a few years ago with my last thread on it.

Anyway, slightly different questions now. My MPG cycles from 0.00 to what I’d say are realistic numbers. This CRUSHES the AVG MPG and it is like 5-8 mpg and I’m measuring on the odo to be 14-18, which I’m pretty sure is as accurate as can be. I love the UG and have a blast geeking out on all it can do, but his has me stumped and I can’t find anything via google on it.

I changed the MPG setting to force MAF and I’ve done the calibration, yet it still does this. Any ideas?

 

I think it gives instantaneous MPG, not average. When you’re idling at a standstill 0 MPG would be correct. When you’re accelerating the number will be ridiculously low and when coasting at speed it will be ridiculously high. I don’t think it’s a very realistic number.

 

I’m starting to think this is MAF related as it stays at zero more often than not now and I’ve had a code on and off leading me to thing the MAF is going. I cleaned it and it doesn’t come back consistently, but I dunno.

I am looking at both Instant and Average MPG in the same gauge. This is how I have it set up.



It seems to randomly go to zero and then cycle to a normal figure. I initially thought it was a setting, but based on the randomness of this, I’m starting to thing the MAF sensor itself.

 

The maf on these go pretty often, if it had near 100k on it she's likely due for a failure.

The little ladies started giving fits right after new O2 sensors. I found a VW with the same Bosh part number maf sensor. The housing wasn't correct but I swapped the the housings out and good to go. Was a 70 dollar part from VW. That's been a year or so ago so it's likely gone up some. I can't remember the VW part number but a search on here should get it

If it doesn't fix it you now have a good spare to keep in the shop. Can't have enough spares when you have a disco.

 

Yep, I definitely know the drill on the MAF sensors for these things. I was just wondering if that would affect why the UG is providing inconsistent data for Instant MPG.

 

While it's a good guess because I believe the other 2 items it pulls from would the abs (speedo) and O2 (a/f ratio).

 

I forced it to read MAF- that’s why I suggested it. I’m not sure what to do other than put a post on the UG forum at this point.

 

Do you have a scan tool that can access real time maf readings?

 

Yes, a couple. I did some searching, but I can’t find the values I should be checking for. Do you know them?

 

Mine had more to do with the o2 readings than the maf readings. The maf wasn't processing air vs rpm and was dumping too much fuel. She went back up to 16-17 MPG once repaired. Torque pro reads avg MPG but I'm not sure if it does real time

When I researched maf readings I got too many different answers.
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