Hi,
Just a bizzare problem with my trip computer on the VR-X.
Every time I fill up, it usually says 500km Range and I reset the trip computer each time.
All things work, so it records the distance travelled, avg speed, avg and inst L/100 etc and range to empty. However my issue is the range to empty is being somewhat problematic.

When I filled up 2 tanks ago, and reset the trip meter, the range to empty was 130 km? No matter how many times I reset it, it refused to alter its opinion. That tank I did 450 km as it recorded that on the distance travelled and I cross checked it against my manual odometer, so that lined up. However, it was flashing no range - - - for 300 km's of my driving experience.

This tank it thought my Range was 400km, and again fell short of the true representation.

Not sure why its doing this, but its bizzare. The range is supposed to calculate based on the Avg fuel cosnumption. Given my car always sits on 14.0l/100, its always consistent. In my wifes TJ Series 2, if I am on the highway, and my average falls to 8.0l/100, it modifies the range to 600 or 700km as it should. Yet on the TJ Series 1, this seems to just never change.

My question firstly is should it change on the TJ series 1, ie the range based on Avg L/100.
Next question, have any of you experienced this issue, and what can I do to resolve it?

Thanks

Note my TJ VR-X Series 1 has a manual odometer and the Trip computer is located above the Air conditioner vents on the dash.

I've been wondering how the car knows you've just put XX L of petrol in it. Fuel level float is the only answer I have, but these are not very reliable and I tend to ignore the "distance to empty" readout, but rely on the warning light instead. If the float level is the only input, your problem may be due to a stuck float.

What does your fuel gauge do when you fill it up? If that works normally - ie doesn't stay down when you fill - the float is ok, and there must be a second way the tank level is measured for the trip meter.

On my TJ the range changes depending on fuel consumption conditions. It may say 500 km if I'm in the city, but taking the car out on the open road the range may go up, or stay the same for 100 km of driving. It cuts out far too early, sometimes goes from 100 km left to "- - -".

What does your fuel gauge do when you fill it up? If that works normally - ie doesn't stay down when you fill - the float is ok, and there must be a second way the tank level is measured for the trip meter.

Hi, my fuel gauge when I fill up rises from Empty to Full (right on the MAX line) over the course of 10 or 15 seconds. Its different to my wifes TJ Series 2, her fuel sender died years ago and was replaced with a newer sender so when you turn the car on, its instant, ie boom, E to F, like that. But in terms of operation it works fine, and on a refill sits on the top.

I'm due to fill up tonight so I'll see what the trip computer does tonight too.

Sounds like the float bit is ok.
There must be another way for the ECU to be aware of the fuel level in the tank, but unfortunately I have NFI. A vertical row of thermistors, perhaps? (Stab in the dark, never seen the pump & float out of the car)

Somebody smarter than me needs to help here. lol

I filled up tonight, it decided to return to 520 km Distance to Empty, so f&*k knows, but no doubt a tank in the future will do something bizzare. Still if anyone knows post away, for now we'll put it down to another of lifes mysteries.

Hmm, nothing much useful to add but I have had some pretty strange things happen with my fuel sender unit (TJII wagon). On several occasions, all during a long drive, after filling the tank and driving for a few minutes the gauge drops to about half, then slowly rises to full over the space of 30 minutes or so. Under normal operation, the gauge reads instantly with no delayed motion. I presume it has something to do with pressure differential (caused by cold fuel into a warm tank maybe?) causing the float to sink or something but I dunno, not something that's easy to check really. As far as I know there's only the one fuel level input device (the float) so possibly the issues are related somehow.

It could be the sender unit in the tank. My wifes TJ before I replaced it could only display half a tank when completely full, and then a few days later, it was completely dead. So I had it replaced and no worries. I think the fuel sender is the first cheapest part to replace in this situation (I may be wrong) but please correct me if I am wrong. I'd start there.

Sorry, I should have stated that this has been happening (rarely) for as long as I've had the car (about 5 or 6 years). 99.9% of the time it's fine, only under those circumstances it seems to give weird readings. My guess is that the cold fuel expands rapidly once in the warm tank (compared to the underground tanks at the servo) and the pressure in the tank rises quickly. The increased pressure causes the float to contract a bit, reducing its buoyancy. This is all just guesswork of course. It's not really an issue, I just figured that it might be related to your issue with the trip computer's distance-to-empty calculation.