Usable fuel tank capacity in '68 IIa 88"

[gaxdad]

I am getting about 6 gallons from the fuel tank in my '68 IIa 88". I believe the capacity is supposed to be 10 gallons.

Is this typical?

I'm not having any issues with the tank. No leaks or other problems.

Thanks - Wes


BTW - Great forum. I'm new here. Rovers North is now on the list of packages I need to grab before my wife sees them. Newbie questions to follow (but only after a careful review of prior posts). Here is a picture of my truck (assuming I can master the process of posting a picture....) - That should cover all the typical newbie statements.

[lumpydog]

Welcome to the forum!

Are you basing this off of your fuel gauge? In other words, it goes to empty and when you fill it up, it takes only 6 gallons? Short wheelbase (88) capacity is typically 12 Gallons.

Also - I have a 68 as well if you need to compare notes on anything, our trucks should be identical. My Chassis number 24434013D.

[gaxdad]

Thanks. I ran the truck down to E on the gauge this weekend and it was sputtering a bit when I finally pulled into a gas station. Filled it up and 6 gallons is all it took. Perhaps I'll put a gas can in the truck and run it until it truly runs out to be sure.

I'll definitely take you up on any G2 you have on your 68. Beautiful truck - a bit cleaner and shinier than mine.

What kind of Overdrive do you have installed? Mine has a Roverdrive from Global Roamer. Probably needs a bit of TLC - it works but the whine is louder than I assume is healthy.

Wes

[lumpydog]

Wes

That fuel mystery is best solved by taking the top-of-seat-box plate off (under the passenger seat - 6 screws) and pulling the fuel sender (round - 6 screws) to see how much fuel is really there. While you have it out, you can inspect the fuel sender to see if it looks to be ok. Is your tank reading full and then running all the way through to empty as you use the 6 gallons? Another related question. Is your engine temp needle (when fully warmed up and driving) in the middle of the range - on "N"?

I have a Fairey overdive. Was installed about 13K miles ago. Really nice to have it. The Roverdrives are great/newer. My experience with the Fairey is that it whines. Haven't been in a truck with the Roverdrive but the same probably applies. Make sure the oil level is ok. If you haven't done so - never hurts to drain and fill with new oil, so you know when it was last changed. I believe Fairey recommends every 6K miles - not sure about Roverdrive.

Charlie

P.S. Feel free to reach out directly "pendletons at gmail dot com". Would love to see pics of your interior and engine as a point of comparison!

[TedW]

Just a thought: Check your draw tube to confirm that it is reaching the bottom of the tank.

It's interesting to read that your gauge reads empty when the truck starts to sputter: Perhaps that the draw tube is bent upwards for some reason and the sender is catching on it.

Either that or you have some very clever (and evil) friends who managed to put some bricks on your tank as a cruel practical joke. :P

[gaxdad]

Luckily my clever and evil friends haven't turned their sights toward my LR yet.

I'll check the fuel sender and inspect the tank this week.

Thanks

Wes

[gaxdad]

I'll send over some pics so we can compare.

Good idea on the Roverdrive oil level and an oil change. Can't hurt.

RE: Temp Gauge - that is the only gauge not working properly. I have a replacement Smiths gauge on the way.

Thanks

Wes

[lumpydog]

RE: Temp Gauge - that is the only gauge not working properly. I have a replacement Smiths gauge on the way.

Thanks

Wes

Ok - I asked because the Temp Gauge and Fuel Gauge are fed power a little differently (along with the oil pressure gauge if you have an original). They all require a 10v power supply to read correctly - so there is a "Voltage Stabilizer" in the mix, that converts the system's 12v down to 10v. If that fails or is failing (outputting incorrect voltage), you will get bad readings in the Fuel and Temp gauges - which expect 10v. Any different and they are no longer accurate.

The voltage stabilizer looks like this. Our host does not sell/stock them so I hope it's ok to link here.

The way the Voltage Stabilizer works - it rapidly cuts in/out the 12v power source - effectively 'down averaging' it to 10v. You can check your voltage stabilizer with an analog multi-meter - but a digital multi-meter will not be able to reconcile the rapid cut in/out of the Voltage Stabilizer. The analog multi-meter will show an average of 10v if the Voltage Stabilizer is functional.

I really like Moss Motor's replica/solid state voltage stabilizer. It electronically converts the 12v input to a solid 10v output that can be tested with a digital or analog multi-meter.

Good article here on testing the stabilizer, as you rule out potential problems.

Looking forward to seeing pics. I have some other cool thing to share via email.

Charlie

[cedryck]

Thanks for the Link to Moss, cool to see improvements on old items.

[gaxdad]

Looks like your insight on the voltage stabilizer was accurate. I found it in a different place than the service manual diagram indicated. Disconnected.



I'll have to hook it up and test it. I have a suspicion that it may not work and thus was bypassed.

Thanks for the insight and advice.

Wes

[cedryck]

[QUOTE=gaxdad;109068]Looks like your insight on the voltage stabilizer was accurate. I found it in a different place than the service manual diagram indicated. Disconnected.



I'll have to hook it up and test it. I have a suspicion that it may not work and thus was bypassed.

Thanks for the insight and advice.

Wes[/QUOTE

Hook it up, should make a difference.

[lumpydog]

That's actually the right place/location for the stabilizer and is where it's located in my truck (I've seen it in the same location in other 68s - so I believe that to the be the factory location). The way yours is setup - it's probably taking a straight 12V which will not allow the instruments to work properly - if at all.

For peace of mind - I'd get the Moss replica. Either way, make sure it is grounded - as your current unit is - to the firewall. Dark green wire (12v source) goes to the "B" terminal on the stabilizer. And then a lighter green wire goes from the "I" terminal on the Stabilizer to the Fuel Gauge and another light green wire goes from the other "I" terminal to the temp gauge.

Alternatively, you can go single wire from "I" post to fuel or temp gauge and then jumper a light green wire from one gauge to the other gauge.

[Edit] P.S. It's a good idea to take the negative lead off the battery terminal when you mess with the wiring. Don't ask how I know this ;-)

[gaxdad]

I dug into the rats nest in my dash and hooked up the voltage stabilizer this afternoon. The results weren't conclusive.

I connected the green wire that was connected to the fuel gauge to the B terminal. (After a bit of detective work to confirm that I had B and I sorted - since they aren't labeled. ). I then connected new leads from the I terminal to the fuel and temp gauges.

Once I started the truck the fuel gauge indicated ~ 1/2 tank ( the tank is almost full). The temp gauge didn't do a thing even after I let the engine warm up.

Voltmeter:

I checked the voltage stabilizer with an analog meter. The needle vacillated between 10 and 12+ volts. I assume this is a positive sign.

Fuel Gauge

I also checked the fuel gauge while connected to the voltage stabilizer (same behavior). I also tried with the fuel gauge connected without the voltage stabilizer - a steady 8 volts. Hmmm.... then I realized that I DON'T have a Smiths fuel gauge. It is labeled British Jaeger. I need to research this and determine whether this gauge requires alternate voltage vs Smiths. My initial search turned up nothing but eBay listings and other sales sites. For all I know they are just Smiths gauges with a Jaeger label.



Temp gauge:

I need retry this test with the voltage stabilizer. I tested with the voltmeter and got the same vacillation between 10 - 12+ volts. But I'm not sure I had the right connection. I retested without the stabilizer and got a steady 12 volts (between either of the terminals with green wires and the black connection that I believe is the ground and the sender to the temp sensor).

Here is is a picture of the connections on temp gauge. I had no luck finding any documentation in the web indicating the wiring labels for each terminal. I'm hoping that someone here can help me sort which is the correct one to connect to the I terminal.


(Temp on the right. Oil on the left (fully functional) They share one lead which I assume is ground)

Front of temp gauge:


(Thanks iPhone for the wonky rotation...)

Thanks again to all for the Insights and Advice.

Wes

[gaxdad]

Note: I found British Jaeger on the Smiths Wiki page. So now I know that the gauges are likely just Smiths gauges labeled as Jaeger.

Should I assume that these also require the voltage stabilizer to function properly?

[lumpydog]

Wes - I Emailed you last night but here is more thinking on this and also replies to some of your post here in the forum, for others to see and weigh in as well. Yes, Jaeger and Smiths merged somewhere along the way.

For a 68 truck, It looks like someone has been busy with your gauges! This is pretty common from what I've seen - people like adding gauges to these trucks. For a 1968 NADA truck, the left large gauge appears to have been swapped out with a different model cluster. 68s had two "pods" within that left larger gauge - a "Water Temp" pod and a "Fuel" pod. Yours says "Amps" and "Fuel" - I think it's from an earlier model truck.

Either way, the Fuel "pod" within that cluster (pods were swappable and could be replaced) has the straight-style needle - which is the newer style for negative earth trucks and it should work - but needs 10V (from the Voltage Stabilizer) and also needs to be paired with the correct Fuel Sender in the tank.

Having messed with the fuel gauge and sender in the past, I also found that the fuel sender needs to be grounded. If the tank is well painted - the paint is an insulator and the tank will not be properly grounded to the chassis - so the sender will not be grounded. Mine was like this so I ran a wire directly from one of the circular fuel sender's fixing screws to a screw that penetrated metal on metal into the chassis (I used one of the brake line mounting clamp's fixing screws).

You can test the fuel sender using an Ohm meter - see this post (mine from a long time ago) and the solutions.

The Amp meter is something I have not messed with. If you plan to leave it there, others here will need to chime in!

You can purchase the correct gauge cluster for your model truck here (Note the matching needle type). But that would leave you with a redundant water temp gauge. You could pull the redundant smaller water temp gauge and move the oil pressure gauge to its spot where it belongs and then replace the left over upper small gauge spot with the original ash tray.

Or just leave it all as is and see if you can get all of them running :-)

Your oil pressure gauge is electric and should require 10v as well, from the voltage stabilizer. What is it reading when running?