Fuel guage stops working when the car is moving

[Mike Wakeham]

Hey folks, I'm after a bit of help. I have a really wierd problem with my fuel guage. For some strange reason it stops working when ever the car is moving. The fuel guage will give a perfect readout when the car is stationary with the enigine running but as soon as it moves, even a couple of inches, it stops working, the needle will drop well below the empty mark. I know it is receiving power as these guages are designed to 'freeze' without power so it should stay on it's origanal reading, but it doesn't.

I have checked the obvious stuff but haven't pulled out the sender from the tank yet. Could this be causing the problem?? It's really doing my head in! Has this happened to anyone else?

My car is a 98 V6, only engine mods I have done are a CAI and exaust. Any help would be great.

[twoie]

is there a pressure relief when you take the gas cap off after it has been running?

twoie

[PATDIESEL]

I cannot see how the pressure would effect it that way (gas cap). My bet is the sender unit, but it is just that, a guess. I've never heard of that problem before.

[Mike Wakeham]

Thanks for the reply guys.
I am getting pressure relief when I take the fuel cap off. Gonna pull the sender from the tank tonight and see if that's at fault.
Only other thing I can think of is there is a short on the dash somewhere, as the speedo gives a reading the fuel needle drops. But I have pulled the clocks out and the circuit board on the back looks fine. Every thing else on my car works perfectly. This is the only problem I've had with my MX in nearly 2 years of owning it. Gotta be said great cars!!

[Mike Wakeham]

This is really wierd, went and filled up today and hey presto, the bloody guage starts to work properly again. Never found outwhat was causing the problem but it seems to have fixed it's self. Just hope it doesn't happen again!!

[Tropical Emerald 1993]

yes that fuel gauge can be weird, check out this :
http://www.mx-3.com/phpbb2/viewtopic.php?t=53396