BJ70 Temp. Gage Readings Question

[futura22]

Hello all, every once in awhile my fuel gage and temp gage spike to the top of their readings, so in other words, fuel goes way above "full" and temp goes into the red. Then they both seem to settle back within their normal readings seconds later. I hear this has to do with the fuel gage shorting out? Although this does concern me a bit, it doesn't as much as when the temp gage stays above the middle mark on the gage so the reading is basically telling me I am slightly overheating the engine. It has done this to me as well on odd random readings as well.. I do not know however if the high temp gage readings are related to the fuel gage shorting out or if I am actually overheating the engine. I mean, 8x out of 10 the gages are reading normal, but i worry when i see the gage reading semi hot. Any info would be greatly appreciated, thanks.

 

[NGray]

Everything I've read states you can't follow the standard gauges. A pyro would probably be a very wise investment then you will know exactly what is going on. My fuel gauge works fine until I get to around 150km then it reads empty. I just go off distance

 

[Chester]

Your description is similar to what is fairly common on the FJ62. it gave me fits for years until I put some fresh solder on the nodes of the contacts on the gauge. On the 62, fuel and temp. share the common. Not sure how it's wired up on the 70's, but the're both of the same vintage and thoroughly Toyota, so I'm figurin' it might be the same. Plenty of the threads on the issue on the 60's pages.

 

[Gun Runner 5]

If the temp. and fuel gauge spikes at the same time (they share a common power source) you are definitely dealing with a "grounding" issue. My HJ75 did that on occasion. My water temp. always ran in lower 1/3 of the gauge and over time would creep up near the 1/2 range. A new t-stat corrected that issue.

 

[futura22]

Hey thanks for the info, yea both Gages spike at the time (fuel and temp.) but sometimes I notice the temp gage sitting a little above the halfway mark without a spike and not sure if it is a clean reading, but I would say no however now. I will look into aftermarket gages I guess and ground? I really do not want to overheat the engine by an accident and cause expensive damage. Cheers

 

[Gun Runner 5]

Do you know if the t-stat has ever been changed?

 

[sadam_husain]

assuming its a 3b engine being a bj70 cruiser those things are robust little tractor engines and don't overheat anyway. The problem with relying on factory temp gauges is its always too late and they only really tell you when it has overheated and not when its starting to overheat due to the factory flat spot in the gauge, if your really concerned about temp as said earlier install a pyro gauge and a good aftermarket mechanical temp gauge, I put 2 5/8" autometer gauges in both my cruisers and always drive by them