fuel pressure and pump on '83 300SD
#1
11-06-2010, 06:44 PM
fuel pressure and pump on '83 300SD
Anyone know what proper fuel pressure is supposed to be after secondary pump or going into it? but before IP?
Aslo, is there an external lift pump or in the tank?
I hear a pump running when I first turn the key to on position but only intermittently or I seem to hear it only after car warms up?
It will stay running as long as the key is on though if it is on.
Car had lost power earlier today and then died and I wonder if I have a fuel pump dying? or is that pump something else?
thanks
Aslo, is there an external lift pump or in the tank?
I hear a pump running when I first turn the key to on position but only intermittently or I seem to hear it only after car warms up?
It will stay running as long as the key is on though if it is on.
Car had lost power earlier today and then died and I wonder if I have a fuel pump dying? or is that pump something else?
thanks
#2
11-07-2010, 01:55 AM
The Fuel Supply/Lift Pump is located on the side of the Fuel Injection Pump.
Start with the Spin-on Filter and trace the Tubing on down the part that has another Hose and the small Plastic filter hooked to it.
I do not know what you are hearing when you turn the key but the Fuel Supply/Lift Pump is mechanicaland only works when the Engine is moving.
If there is an Electric Pump somewhere; someone must have added it.
Start with the Spin-on Filter and trace the Tubing on down the part that has another Hose and the small Plastic filter hooked to it.
I do not know what you are hearing when you turn the key but the Fuel Supply/Lift Pump is mechanicaland only works when the Engine is moving.
If there is an Electric Pump somewhere; someone must have added it.
#4
11-07-2010, 01:45 AM
I read recently on forum (forced induction?) that there's a vacuum motor in the back that goes on at odd times,that might be it. I hear a motor like that sometimes in mine and I don't have any extra fuel pump.
You could have a lot of things wrong, I'd say the lift pump would be low on the probability list. Blocked fuel filter would be one of the most likely.
Then there's the breather in the fuel tank - you can test that by loosening the filler cap and see if it stops the problem. Or could be an air leak in the fuel system which is also quite easy to test for.
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You could have a lot of things wrong, I'd say the lift pump would be low on the probability list. Blocked fuel filter would be one of the most likely.
Then there's the breather in the fuel tank - you can test that by loosening the filler cap and see if it stops the problem. Or could be an air leak in the fuel system which is also quite easy to test for.
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Dodge Magnum History
Last edited by paddo; 02-19-2011 at 02:19 AM.
#5
11-07-2010, 07:37 PM
Thanks folks, much appreciated. I let engine run today and it started dying so I looked under hood and the primary filter was not getting much fuel (or intermittently sometimes) its brand new. So that tells me the screen in tank is clogged or air getting into the lines from there back OR lift pump is failing right?
thanks
thanks
#6
11-07-2010, 09:01 PM
By primary filter you mean the small inline filter right? How are you diagnosing poor flow through the inline/primary filter?
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Last edited by paddo; 02-19-2011 at 02:20 AM.
#7
11-08-2010, 06:14 AM
Paddo
Yes, "they" call the small plastic a primary (first one fuel comes to) I call it a secondary (since its only like 50mc) lol.
When car is running you an see hardly any fuel going through the thing (as opposed to BEFORE this all happened). Especially when you press accelerator almost no fuel goes through. Even at idle you can see pockets of where it goes down to almost no flow. When the car is running GOOD, you can see the filter full of fuel and its moving through nicely.
FI
When you say switch supply and return lines. DO you mean at the tank, swap the two around? Didn't know that would work? Humm. I'll give that a try. THanks.
If fuel flows through like it was before, must/could be the strainer?
It is to note, I ran the tank almost down to empty probably only a 1/2 gallon left in tank. I did that twice, I wonder if it dragged a bunch of **** into the strainer? I emptied the tank into a bucket then my line of thinking was to put only a gallon of diesel/kero/injector cleaner through it and purge the system. Maybe I should simply put 1/2 tank or better through it. ??
I am going to get the 46mm socket today and see what I got, since its empty right now and fuel lines are disconnected anyway.
I DO notice a LOT of nasty black crud smells like old diesel STILL entering the filters even after I have put 200miles of my cleaning mixture through the system. I've been through 6 filters in all. I am tempted once I get the strainer out to try and wash it out with a hose and let it dry real well.
Thanks again. This is just ONE problem, then I gotta figure out the tranny thing. lol.
SPeaking of which, if it shifts well but smells burned is that telling me what it could be?
SOmeone told me to run it for a few hundred miles then change the tranny filter and fluid AGAIN. Will this do any good or help it? Also with oil change he said to same.
Would synthetic help?
Yes, "they" call the small plastic a primary (first one fuel comes to) I call it a secondary (since its only like 50mc) lol.
When car is running you an see hardly any fuel going through the thing (as opposed to BEFORE this all happened). Especially when you press accelerator almost no fuel goes through. Even at idle you can see pockets of where it goes down to almost no flow. When the car is running GOOD, you can see the filter full of fuel and its moving through nicely.
FI
When you say switch supply and return lines. DO you mean at the tank, swap the two around? Didn't know that would work? Humm. I'll give that a try. THanks.
If fuel flows through like it was before, must/could be the strainer?
It is to note, I ran the tank almost down to empty probably only a 1/2 gallon left in tank. I did that twice, I wonder if it dragged a bunch of **** into the strainer? I emptied the tank into a bucket then my line of thinking was to put only a gallon of diesel/kero/injector cleaner through it and purge the system. Maybe I should simply put 1/2 tank or better through it. ??
I am going to get the 46mm socket today and see what I got, since its empty right now and fuel lines are disconnected anyway.
I DO notice a LOT of nasty black crud smells like old diesel STILL entering the filters even after I have put 200miles of my cleaning mixture through the system. I've been through 6 filters in all. I am tempted once I get the strainer out to try and wash it out with a hose and let it dry real well.
Thanks again. This is just ONE problem, then I gotta figure out the tranny thing. lol.
SPeaking of which, if it shifts well but smells burned is that telling me what it could be?
SOmeone told me to run it for a few hundred miles then change the tranny filter and fluid AGAIN. Will this do any good or help it? Also with oil change he said to same.
Would synthetic help?
Last edited by Hounds; 11-08-2010 at 06:16 AM.
#8
11-08-2010, 01:22 PM
It is very easy to swap the supply and return lines under the hood with a screw driver applied to hose clamps. YOu should see the supply one going to the primary filter, and the return line is right next to it - the "cigar" hose. I htnk it's much harder at the tank.
If you are taking the screen out anyway then it shouldn't be necessary but is a very easy test b4 you do so, to see if that is your problem.
Are you familiar with operation of the hand primer pump? Pump that for a while and watch the fuel flow. If it's hard to pump and there's poor fuel flow then you have a blockage. If it's very easy to pump with poor fuel flow, then I think one of the valves in the lift pump is probably stuck open - I had that just this last week.
If you've gone through 6 primary filters and haven't replaced the spin-on, then your spin-on filter is probably clogged and that's your problem. As D9112 says, you can test the spin-on by removing the banjo fitting of the input line that goes to the spin-on housing - mine has an arrow pointing in to the spin-on. Another way might be to unscrew the spin-on and hold a jar under where it goes, and pump the primer pump to check the flow. If the flow is normal again that suggests a clogged spin-on.
The other possibility is air getting in - I have some clear tubing installed at a couple of spots of the fuel hoses, so I can easily see if air bubbles are getting in the fuel.
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MK-MOTORSPORT
If you are taking the screen out anyway then it shouldn't be necessary but is a very easy test b4 you do so, to see if that is your problem.
Are you familiar with operation of the hand primer pump? Pump that for a while and watch the fuel flow. If it's hard to pump and there's poor fuel flow then you have a blockage. If it's very easy to pump with poor fuel flow, then I think one of the valves in the lift pump is probably stuck open - I had that just this last week.
If you've gone through 6 primary filters and haven't replaced the spin-on, then your spin-on filter is probably clogged and that's your problem. As D9112 says, you can test the spin-on by removing the banjo fitting of the input line that goes to the spin-on housing - mine has an arrow pointing in to the spin-on. Another way might be to unscrew the spin-on and hold a jar under where it goes, and pump the primer pump to check the flow. If the flow is normal again that suggests a clogged spin-on.
The other possibility is air getting in - I have some clear tubing installed at a couple of spots of the fuel hoses, so I can easily see if air bubbles are getting in the fuel.
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MK-MOTORSPORT
Last edited by paddo; 02-19-2011 at 02:21 AM.
#9
11-08-2010, 03:25 PM
Solved the problem today. Took the screen out of tank and it was CLOGGED beyond recognition. lol
Flow went great after that and I had tons of power back.
Oh, how quick is it to take the tank out? All I see are 4 nuts holding a bracket on? Is that it? After taking the supply line and return line off? Will it come right out the trunk?
If so, I want to take it out and flush/clean with gasoline.
Thanks folks.
Flow went great after that and I had tons of power back.
Oh, how quick is it to take the tank out? All I see are 4 nuts holding a bracket on? Is that it? After taking the supply line and return line off? Will it come right out the trunk?
If so, I want to take it out and flush/clean with gasoline.
Thanks folks.
#10
11-08-2010, 04:28 PM
It is easier to change the Spin-on/Secondary Filter than it is to make a mess testing it.
Before you install the new one fill it with clean Diesel Fuel and start pumping on the Hand Primer until you hear a buzzing or squishing sound everytime you Pump on the Hand Primer.
If you try to start and it does not want to start loosen some of the Fue Injection Line Nuts at the Injectors; crank the Engine until you see fuel coming out from under the nuts (to be sure the Air is Bleed out); tighten the Nuts and attempt to start.
Before you install the new one fill it with clean Diesel Fuel and start pumping on the Hand Primer until you hear a buzzing or squishing sound everytime you Pump on the Hand Primer.
If you try to start and it does not want to start loosen some of the Fue Injection Line Nuts at the Injectors; crank the Engine until you see fuel coming out from under the nuts (to be sure the Air is Bleed out); tighten the Nuts and attempt to start.