Gas guage bounces

[cboag]

I am on my second Supra. In the 89 Comp and now in my 02 Santera the gas gauage bounces after it gets down to about 3/4 full.

Thanks

[88SupraComp]

I don't have any solution, but mine does the same thing on my 88 comp. The fuel needle seems to move around when I turn on other accessories such as the radio, blowers, etc. The low fuel light goes on prematurely also.

[IUFAN24]

My 87 Sunsport JUST starting doing that on Sunday after about 2 hours on the water.

Fuel sending unit, gas tank float issues or ???????

[michael hunter]

When I purchased my 89 Sunsport I had the same problem I found a replacement fuel sender in an ad in Trailer Boat magazine . I don't remember the name of the company but they were out of florida.
I never had a problem since .Try Google if you can't find it let me know and Ill see if there is a name on it.

[Dinoz]

Anyone have any idea how much gas an '89 Comp holds??? I can't find that info anywhere..

Thanks,

DZ.

[DKJBama92Mariah]

Anyone have any idea how much gas an '89 Comp holds??? I can't find that info anywhere..

Thanks,

DZ.

Capacity should be printed on a label on top of the tank itself.


I don't have any solution, but mine does the same thing on my 88 comp. The fuel needle seems to move around when I turn on other accessories such as the radio, blowers, etc.


If your gauges move when you turn accessories on and off, you have a power problem behind the dash. Check all power and ground wires going to and from the gauges. My gut says a bad ground. If you don't have a multimeter, now would be a good time...

[milner351]

the aluminum fuel tank in my '86 kevlar classic comp was mfr here in Michigan and is labelled at 21 gallons.

however, I've not been able to put 21 gallons in it, and when I put in 20 some of it came out the vent while turning corners on the trailer.

I now only put 6 gallons in at a time.

I purchased a vent valve from iboats - just installed with new vent line with a loop in it, we'll see if that helps. The original hose was a straight run to the vent with no valve no loop.


As for the gauge moving when the boat moves - that's normal - it's a float gauge with not much resistance built in to dampen out movement.

Gauge movement when accessories are turned on and off is most definitely an electrical problem - boat's and 'vettes seem to have the same fiberglass body disease - bad grounds - I've run a #10 wire from the - battery post directly to a ground post behind the dash that I've run my grounds to - that seems to have helped.

I have all new gauges I'll be installing over the winter with a walnut dash I'm building from scratch - lets' hope I get the wiring right on that deal!