Tech Tip: Preparation For Running Out Of Fuel...

[John E. Smith]

Ever made the BIG mistake, and run your Detroit out of fuel???  All of us who have will never forget it... and those of us who haven't never want to.

Well, I have a little trick that I use with Detroits that a mechanic taught me -- years ago when I ran my old Dodge D400 cabover out of fuel.  It had a 318, and try as I might I just could not get it to start -- I had completely emptied the pump & filters!

One of the first things I do whenever I buy any vehicle with a DD engine is to add a couple of fittings to the line coming from the primary fuel filter to the pump, and I add a check-valve to the line from the tank to the primary (or secondary) fuel filter (this is to keep the fuel from back-flowing into the tank when you pressurize -- many older vehicles did not have one in the line).  On the pump side of the primary filter, I add a 90-degree brass elbow with a quick disconnect on the end.  I use the male side with an in-line valve so that I can seal the line up after I get everything going again.

I also carry a small electric fuel pump -- you can get them at any auto parts store for around $30 to $40 -- with about 6 feet of fuel line that ends in the mating quick disconnect.  On the other side of the little pump, I use just enough fuel line to drop into a 5 gallon fuel can.

After that, whenever I ran out of fuel, I simply put enough fuel in the tank to get me to a truck stop, then primed the filters and connected the little pump to my new connection; the other end went into a can full of fuel.  I would turn on the little pump and let it run for a couple of minutes to pressurize the line to the engine's pump, then start up the Detroit.  Once it has run for about 5 minutes with the "assist", shut it down and disconnect your "cheater pump" -- if you used an in-line valve, don't forget to close that before disconnecting!

This little trick has worked time and time again for me, and not just on Detroit engines -- Cat engines can be a ^)&%^(*&$#(*& to get started, too!

John

[Homegrowndiesel]

Good Advise

Bill

[TomC]

Simple solution- use 1/4 tank on the fuel gauge as your empty and time to refill, and it will never happen.  In 1.3 million miles of truck driving, only happened once to me, and that's when my tanks were syphoned.  Besides, it is always better to have the tanks kept full, especially when parking for extended period of time to keep the air pocket as small as you can in the tank to prevent condesation. Good Luck, TomC

[John E. Smith]

Yes, but many of the older coaches don't have functional fuel guages... and MC9's don't have one at all.

[gumpy]

and MC9's don't have one at all.

Fuel gauges were an option on MC9s, and I would bet the majority have them.

[TomC]

Especially transits, like I have, didn't have a fuel gauge.  But I lucked out, in that when I pulled my fuel tank to install the separate fuel pickup and return for the generator, I discovered that the top of the tank had two (!) 5 screw plates just waiting for one of them being used for the fuel gauge (used a standard universal truck pickup that is calibrated for 12v positive reading full and no power reading empty [some use positive for full, no power for half and reverser polarity to bring the needle to empty]) and used the other plate for my gen pickup and return. Currently, my sender needs to be replaced, but I write down the mileage everytime I fill (always fill to the top, or stop the nozzle when the filling whistle stops-I discovered that if you kept going just a few seconds longer, the fuel would spit out the filler when the nozzle finally stopped automatically).  With a 140gal tank, with 90% usuable, the 126gal should average 630 miles (5mpg).  But always get fuel at around 450 miles and usually put in 80-90 gals.  Just my system, and haven't (and won't) run out of fuel.  Good Luck, TomC

[RJ]

John -

How about some pics of your fuel primer parts/system??

Might really help the other newbies!

[belfert]

After that, whenever I ran out of fuel, I simply put enough fuel in the tank to get me to a truck stop, then primed the filters and connected the

This sentence would indicate that you have run out of fuel multiple times.  I don't understand how anyone could make this mistake more than once, unless you are talking on different vehicles.  I did run out on my Ford pickup once, but I had run that route many times so I wasn't watchng the gauge closely.  I ran out 50 miles before my usual fuel stop due to a terrible head wind.  (I had a full 5 gallon can of diesel just in case.)

My fuel gauge didn't work well previously, but I replaced the sender with one from Centroid Products and my gauge reads perfect now.  The two wire sender from Centroid requires a gauge that reads from 33 to 240 ohms (not terribly common).  I was lucky that my guage is a 33/240 already.

Brian Elfert

[kyle4501]

As simple as these fittings are to add, seems a reasonable thing to do as it will make changing the fuel filters an easier job too.

I have heard that the only greyhounds that ran out of fuel had fuel gauges.

Jerry L was telling me about the sending unit he used in his for incredible accuracy, maybe he can chime in.

[Dallas]

Brian,

It's not the driver that runs out of fuel.
I've driven a whole bunch of different trucks and buses that weren't even close to being accurate.
I learned to never, ever, ever, depend on the guage for an accurate reading.
As an example, your gauge may read totally accuratlely now. That does'nt mean it will in the future. Even a voltage change of .005V will affect the reading. That .005V change is due to resistance being built up from crud and corruption.
In a couple of years, after whatever fuel you put in and however long it sits, are you going to be able to trust that guage to be accurate?
There ain't no way.

DO NOT EVER, EVER, EVER Believe your gauges. The only way to know what is actually going on is to get out and check your mechanical  gauges. All that the dash instruments are there for is to give you an "IDEA" of whats going on with your equipment, it is NOT the end all, be all, of your needs.

Again, NEVER EVER believe what you see on the dash board, take it as an "estimate" not a cast in stone reading.

Dallas

[belfert]

author=Dallas link=topic=2248.msg19322#msg19322 date=1161369199]
Brian,
It's not the driver that runs out of fuel.
I've driven a whole bunch of different trucks and buses that weren't even close to being accurate.
I learned to never, ever, ever, depend on the guage for an accurate reading.
As an example, your guage may read totally accuratlely now. That does'nt mean it will in the future. Even a voltage change of .005V will affect the reading.
In a couple of years, after whatever fuel you put in and however long it sits, are you going to be able to trust that guage to be accurate?
There ain't no way.

How come cars and pickup trucks have gauges that tend to work year after year after year?  My dad has 185,000 miles on his Dodge Caravan and the gauges work just as well as day one.  My VW Golf diesel has three years and 50,000 miles and the gauges work like new.

Why is it considered a given that gauges on a bus or heavy truck won't work after a time?

I did have a mechanical temp gauge installed on my bus as a doublecheck on the front gauge.  The new fuel sender I installed has no moving parts so I don't know why it won't be accurate years down the road.  My old sender was the mechanical float type and the contacts were covered in black goop when I took it out so I can see why it was so inaccurate.  (At least it wasn't rusty like some.)

Brian Elfert[]

[kyle4501]

In my experience, most gauges are accurate, for a while anyway. I just don't want to get caught short when the gauge takes a crap. 

Just remember, Murphy was an optimist! 

[buswarrior]

Duty cycle.

If we ran our cars for a million or two miles, the gauges wouldn't work in them either.

Primary decision making for fuel might be suggested to be mileage based, look at the gauge as mildly interesting, and to see if it matches your mileage calculations.

For the typical 8V71 with 144 USgallons:

250 miles, somewhere around half tank.

500 miles safe range on the highway, less if you are doing a lot of city.

Get fuel and fill it to the rim.

happy coaching!
buswarrior

[plyonsMC9]

Hi - Dallas or anyone else who knows about this,

What are the mechanical guages?  All I have seen so far on my MC9 is the in - dash guage.  I'd sure like to know about any mechanical guages.  That sounds like a real good idea!

Thanks - Phil

[Busted Knuckle]

Hi - Dallas or anyone else who knows about this,

What are the mechanical guages?  All I have seen so far on my MC9 is the in - dash guage.  I'd sure like to know about any mechanical guages.  That sounds like a real good idea!

Thanks - Phil

Phil,

Most of us (or previous owners) put a set of mechanical guages in the engine compartment so if our dash guages show something way out of wack we can go to the back and check the "real sittuation out". BK