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pockets
05-26-2013, 01:08 PM
My gas gauge is doing something odd. It shows it from the full mark down to half after it hits the half mark it won't go down anymore. Do any of you know what could be causing it to do this?

Raptor05121
05-26-2013, 04:06 PM
Stuck float

pockets
05-26-2013, 04:19 PM
Thank you

RhinoZ24
05-26-2013, 04:46 PM
Fuel system cleaner might help. It gets gummed up after a while.

pockets
05-26-2013, 06:14 PM
I will try that first.

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Lucas makes fuel system cleaner right? And if not any brands you'd recommend?

masonic
05-26-2013, 07:09 PM
Sea foam

joshpickworth
05-26-2013, 07:33 PM
Sea foam and Lucas are two good products!!! I like to alternate the two of them

pockets
05-26-2013, 07:59 PM
Is there any big differences between sea foam and lucas?

Raptor05121
05-26-2013, 11:33 PM
I'm going to have to revoke everyone's posting rights if it contains the word "seafoam" anywhere in the post.

OP, contrary to popular belief, dumping a magical substance known as "Seafoam" (which is nothing more than naphtha and mineral spirits) into your vehicle will not solve all its problems. Please don't even waste your money.

Now, to actually make some progress: Your gas gauge is microprocessor controlled. Meaning the float in your tank sends an analog signal to the GEM, which then converts it to an electrical signal, which the electromagnet on the back of the gauge converts into moving the needle. Depending on your MY truck (99+), you can go into diagnostic mode on your cluster by holding down the reset button and turning the key to run, which will perform a gauge sweep. This will do two things: First, that will rule out one possibility OR it will go to show that there is a possibility you have water leaking into your GEM terminals, which the gas gauge is one of the known faults. Check for CELs, if you do get one, it should be P9202- Fuel Sending Unit Circuit Open. If this is the case, I can provide you with step by step instructions on how to get to the dash code to determine what the sending unit is sending to the GEM for fuel level readout. If this checks out, your next step would be to remove the bed and physically check the condition of the sending unit.

Before you do ANY of this, I would for sure fill up the tank, and drive it until you are empty, at least once or twice.

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I also forgot to ask: How long has this been going on? Ford has what are called "dummy gauges" in that they do not read true registry values. Our oil pressure, water temp, and voltage gauges all stay put even though the values on them change while driving. The fuel gauge is kind of the same in that it has slosh-prevention in that it reads from the sending unit every few minutes rather than seconds. That is why you will drive for 50 miles after a top-off before it moves, and if you park on an incline, it will take some time for it to read accurately after leveling out. So if this has happened just today, go drive for a few days and report back. Otherwise, keep driving until it is empty and top it off and report back.

pockets
05-26-2013, 11:54 PM
Thank you for all that info it's very helpful. You clearly know what you are talking about.

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My trucks a 91'

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I'm buying the truck from my buddy and he says it's been going on for awhile

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He's run it empty and filled it and it's still doing it.

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Oh and I forgot its throwing some code that has to do with the fuel air ratio or at least I believe that is what he said. Could that be causing the gas gauge to not work properly?

RhinoZ24
05-27-2013, 12:23 AM
I'm going to have to revoke everyone's posting rights if it contains the word "seafoam" anywhere in the post.

OP, contrary to popular belief, dumping a magical substance known as "Seafoam" (which is nothing more than naphtha and mineral spirits) into your vehicle will not solve all its problems. Please don't even waste your money.

Now, to actually make some progress: Your gas gauge is microprocessor controlled. Meaning the float in your tank sends an analog signal to the GEM, which then converts it to an electrical signal, which the electromagnet on the back of the gauge converts into moving the needle. Depending on your MY truck (99+), you can go into diagnostic mode on your cluster by holding down the reset button and turning the key to run, which will perform a gauge sweep. This will do two things: First, that will rule out one possibility OR it will go to show that there is a possibility you have water leaking into your GEM terminals, which the gas gauge is one of the known faults. Check for CELs, if you do get one, it should be P9202- Fuel Sending Unit Circuit Open. If this is the case, I can provide you with step by step instructions on how to get to the dash code to determine what the sending unit is sending to the GEM for fuel level readout. If this checks out, your next step would be to remove the bed and physically check the condition of the sending unit.

Before you do ANY of this, I would for sure fill up the tank, and drive it until you are empty, at least once or twice.

----------

I also forgot to ask: How long has this been going on? Ford has what are called "dummy gauges" in that they do not read true registry values. Our oil pressure, water temp, and voltage gauges all stay put even though the values on them change while driving. The fuel gauge is kind of the same in that it has slosh-prevention in that it reads from the sending unit every few minutes rather than seconds. That is why you will drive for 50 miles after a top-off before it moves, and if you park on an incline, it will take some time for it to read accurately after leveling out. So if this has happened just today, go drive for a few days and report back. Otherwise, keep driving until it is empty and top it off and report back.

This makes my gas gauge so much more understandable lol. I wondered why it took like 40 miles after a fill-up to finally start changing.

Raptor05121
05-27-2013, 09:03 AM
Oh and I forgot its throwing some code that has to do with the fuel air ratio or at least I believe that is what he said. Could that be causing the gas gauge to not work properly?

No, but I would find someone with an OBDI scanner and figure out what code it is and get it fixed. Where is the vehicle coming from? The 91s are older and have less technology in them, do taking the bed off and removing the sending unit might be the ticket.

pockets
05-27-2013, 12:05 PM
My buddy I'm buying the truck from is supposed to take the truck to the shop and have the code fixed this week. He was going to do it last week but never did. Cause it won't pass safety / emissions if it's not fixed

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Taking the bed off shouldn't be to hard right?

RhinoZ24
05-27-2013, 12:13 PM
My buddy I'm buying the truck from is supposed to take the truck to the shop and have the code fixed this week. He was going to do it last week but never did. Cause it won't pass safety / emissions if it's not fixed

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Taking the bed off shouldn't be to hard right?

Nope, it's usually only held on by 4 bolts anyways I believe. Maybe a few other hooks or something too, but not too bad to remove.

Raptor05121
05-28-2013, 09:38 PM
I think Ryan is right. Just four carriage bolts and then the gas filler neck. You need two people, but it is MUCH easier than dropping the tank.

RhinoZ24
05-28-2013, 09:55 PM
I think Ryan is right. Just four carriage bolts and then the gas filler neck. You need two people, but it is MUCH easier than dropping the tank.

Haha the only reason I know is Border Wars on National Geographic. They had to get to marijuana in the gas tank of a Ram 1500 and took off the bed to do it. I'm pretty sure it was only 4 bolts, I'm assuming it's almost the same for most trucks.

pockets
05-28-2013, 11:10 PM
Wth rhino?

RhinoZ24
05-28-2013, 11:33 PM
Wth rhino?

What?

masonic
05-28-2013, 11:37 PM
I have never heard anyone say something negative about seafoam. Can you explain?

Raptor05121
05-28-2013, 11:50 PM
I have never heard anyone say something negative about seafoam. Can you explain?

Seafoam is useful as a cleaning agent, that's it. I've used it to clean an intake manifold when I was rebuilding an engine. It removes carbon buildup pretty well. But to put it down vac lines, brake booster lines, fuel tanks, and oil- you'll (read: RISK) mess something up. These engines were designed to run as-is. Ask Ford if its a good idea to stuff liquid down those lines. They and ever other automotive manufacturer will tell you no. The only thing that is supposed to go through a gas tank is gasoline. The only thing designed to go in an oil pan is oil. Same thing for vac lines- air only. If you suck it up a vac line, you risk hydrolocking the engine. Not to mention it will foul plugs, erode your piston rings, and also ruin your O2/cat converters (despite all the marketing by Seafoam saying its safe, I've got a $500 bill from Ford saying otherwise). I've used seafoam once, and it costs me over $500 to replace the O2 sensors and rear catalytic converters. Secondly, when do you introduce it to the internals of the engine, you change the stiochiometry since naphtha burns differently than 87 octane fuel. So you're risking pinging/predetonation. Now it WILL remove that carbon buildup you're trying to get to, but guess where it is going? Through the combustion chamber. Introduce a slag of carbon big enough, and you'll have a expensive paperweight in your truck. I've got a shelf of aviation maintenance publications, and part of one of them discusses fuel/engine additives such as Gum-Out, Seafoam, etc (aviation engines are A LOT more sensitive than automotive engines) and basically all of them are a no-no.

Seafoam is a snake-oil that was introduced to take advantage of the lesser-informed automotive enthusiast. If you're going to do something, do it right. If you need to clean your intake, take it off the engine first. Your injectors can be cleaned using Techron which is used in Shell gasoline. If you have blow-by of your rings, its time to rehone your cylinders and re-ring your pistons. A simple $5 bottle of flammable substance with a lot of marketing isn't going to fix every problem on your vehicle.

Disclaimer: The above writing is my opinion and mine only. I have met mechanics who love Seafoam and everything to do with it while others (myself) wouldn't run it through a weedeater bought from a yard sale. Like all other things found on the internet, take the above writing with a grain of salt.

pockets
05-29-2013, 01:04 AM
Wow is all I've got to say to that and it's also informing in a opion kind of way...

RhinoZ24
05-29-2013, 01:07 AM
Wow is all I've got to say to that and it's also informing in a opion kind of way...

I'm still wondering what was wrong with what I said about how I know how to take the bed off of a truck? Lol

joshpickworth
05-29-2013, 05:38 AM
so what about the Lucas products? Like the injector cleaner, fuel treatment and oil treatment?!?

Jersey_Joe
05-29-2013, 07:31 AM
Lucas has always been a good product. Try Zmax. Best product on the market imo

Raptor05121
05-29-2013, 09:44 AM
Its all personal preference. Like I said, if you want to clean something, take it off and clean it. I won't put anything in the gas tank that isnt gas. Shell's Techron is excellent for removing carbon valve buildup.

masonic
05-29-2013, 10:24 AM
I can count on one hand how many bottles of seafoam I've bought, but it always seemed to help. I've only ever used it in the gas tank, I thought that it kind of worked like av gas.

Jersey_Joe
05-29-2013, 12:13 PM
Its all personal preference. Like I said, if you want to clean something, take it off and clean it. I won't put anything in the gas tank that isnt gas. Shell's Techron is excellent for removing carbon valve buildup.

U like shell huh? Hard to find around here

RhinoZ24
05-29-2013, 12:25 PM
I like Mobil, my truck likes their gas the best, Chevron is right behind along with Shell. 76 is the worst, gave my truck the worst rough idle when I used them only 1 time.

pockets
05-29-2013, 12:43 PM
I'm still wondering what was wrong with what I said about how I know how to take the bed off of a truck? Lol

The wow part wasn't directed at you ok it was directed at the mass info. I've never known anyone who knew or felt so strongly against seafoam blew my mind a bit was all. And why in the hell would someone put weed in a gas tank?

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And speaking of gas... just so you all know Maverick gas which I refuse to use is horrible horrible gas it clogs fuel filters like no tomorrow. Cosco gas is also bad.

I like chevron gas and I forgot what the other one is I like.

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joshpickworth
05-29-2013, 01:12 PM
To smuggle it

RhinoZ24
05-29-2013, 01:15 PM
The wow part wasn't directed at you ok it was directed at the mass info. I've never known anyone who knew or felt so strongly against seafoam blew my mind a bit was all. And why in the hell would someone put weed in a gas tank?

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And speaking of gas... just so you all know Maverick gas which I refuse to use is horrible horrible gas it clogs fuel filters like no tomorrow. Cosco gas is also bad.

I like chevron gas and I forgot what the other one is I like.

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Exactly what Josh said, they do that to smuggle it into the U.S. from Mexico.

joshpickworth
05-29-2013, 01:19 PM
lol they caught a Mexican on a surfboard pulling a second one behind him with weed strapped to the bottom of both

pockets
05-29-2013, 01:29 PM
What is this world coming to?

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Exactly what Josh said, they do that to smuggle it into the U.S. from Mexico.

But IN the tank really that's just awful and it can't be good for the person smoking that crap. Its probably not good for the truck either

Jersey_Joe
05-29-2013, 02:48 PM
Seafoam is useful as a cleaning agent, that's it. I've used it to clean an intake manifold when I was rebuilding an engine. It removes carbon buildup pretty well. But to put it down vac lines, brake booster lines, fuel tanks, and oil- you'll (read: RISK) mess something up. These engines were designed to run as-is. Ask Ford if its a good idea to stuff liquid down those lines. They and ever other automotive manufacturer will tell you no. The only thing that is supposed to go through a gas tank is gasoline. The only thing designed to go in an oil pan is oil. Same thing for vac lines- air only. If you suck it up a vac line, you risk hydrolocking the engine. Not to mention it will foul plugs, erode your piston rings, and also ruin your O2/cat converters (despite all the marketing by Seafoam saying its safe, I've got a $500 bill from Ford saying otherwise). I've used seafoam once, and it costs me over $500 to replace the O2 sensors and rear catalytic converters. Secondly, when do you introduce it to the internals of the engine, you change the stiochiometry since naphtha burns differently than 87 octane fuel. So you're risking pinging/predetonation. Now it WILL remove that carbon buildup you're trying to get to, but guess where it is going? Through the combustion chamber. Introduce a slag of carbon big enough, and you'll have a expensive paperweight in your truck. I've got a shelf of aviation maintenance publications, and part of one of them discusses fuel/engine additives such as Gum-Out, Seafoam, etc (aviation engines are A LOT more sensitive than automotive engines) and basically all of them are a no-no.

Seafoam is a snake-oil that was introduced to take advantage of the lesser-informed automotive enthusiast. If you're going to do something, do it right. If you need to clean your intake, take it off the engine first. Your injectors can be cleaned using Techron which is used in Shell gasoline. If you have blow-by of your rings, its time to rehone your cylinders and re-ring your pistons. A simple $5 bottle of flammable substance with a lot of marketing isn't going to fix every problem on your vehicle.

Disclaimer: The above writing is my opinion and mine only. I have met mechanics who love Seafoam and everything to do with it while others (myself) wouldn't run it through a weedeater bought from a yard sale. Like all other things found on the internet, take the above writing with a grain of salt.

Great write Alex. As always. I'm NOT a fan of seafoam at all unless I'm simply trying to clean parts. That's it.

pockets
05-29-2013, 03:26 PM
I haven't ever used seafoam. I've only used Lucas.

RhinoZ24
05-29-2013, 05:32 PM
I haven't ever used seafoam. I've only used Lucas.

Lucas or ZMax

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What is this world coming to?

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But IN the tank really that's just awful and it can't be good for the person smoking that crap. Its probably not good for the truck either

The drug cartels don't care about the people buying their drugs or how they get to the U.S., they just care about money.

pockets
05-29-2013, 09:28 PM
True but still its kind of sickening.

RhinoZ24
05-29-2013, 10:52 PM
Well, don't buy weed from south of the border and you're all good lol.

pockets
05-30-2013, 12:08 AM
I don't buy weed period cause I don't smoke it.

RhinoZ24
05-30-2013, 12:11 AM
I don't buy weed period cause I don't smoke it.

Good idea haha

pockets
05-30-2013, 12:16 AM
Yeah...