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Electric fuel pump burns up......4th time

  
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Electric fuel pump burns up......4th time

 
69B5Blue 69B5Blue
New User | Posts: 4 | Joined: 01/14
Posted: 01/12/14
02:10 PM

Hi Folks,

I'm new to the forum and have come for some help and advice....

I'm restoring a 69 Charger 440 and after 8 years, I have it on the road.  The only problem I am having is I can't seem to keep the Elctric fuel pump from burning up.  I can make it through a couple of tanks of gas or so and that's about it.  For some reason, I keep burning up fuel pumps.  I have a 440 - 6 Pack with a full roller assembly pumping out a decent amount of horses but can't enjoy a long drive until I solve this issue.....here's my questions.....

1). I have the pump mounted under the trunk by the fuel tank and sitting at the hight if the top of the tank or more.  Is it possible the fuel pump is loosing prime and running dry causing them to burn up?  Maybe if it is lower than the tank it would stay primed better?

2). Do I need any kind of return line?

3). The pump runs continuously when I turn the key on and as the engine is running so it never cycles off...is that ok?

I would sure appreciate any help I can get....Hot August Nights has been calling my name and I want to make sure I get this under control so I can go this year!  Thank you in advance for any help you guys can give me!  

ddemello ddemello
New User | Posts: 16 | Joined: 01/14
Posted: 01/12/14
03:17 PM

some suggestions. use 2 small wires to power the pump instead of one big one [do the same thing with the ground wires]. use a holley blue pump or an equal. use a 1/2" line after the pump, plumb it to a barry grant spool/diverter, then a pressure regulator. plumb the regulator to a fuel log that feeds the carbs. use a tee or y for the fuel return, use the blow off port of the regulator for a 1/4 inch return line back to the tank. plumb both the blow off port and the diverter to the return  or you can do whatever some one else tells you that does not agree with me. thats how life works. good luck to you. Grin  

wayne712222 wayne712222
User | Posts: 67 | Joined: 10/13
Posted: 01/12/14
06:32 PM

just curious...  

is there a strainer on the end of the pick up tube to prevent air bubbles from going thru the pump.. ???



what kind of pump.. got a part number???

some pumps are NOT built with a bypass circuit inside to limit output pressure..  holley red and blue pumps have a spring loaded piston that when the pressure comes up the pressure above the calibration of the spring pushes the piston backwards and allows the fuel to circulate back into the inlet.. so it does not build pressure above the max setting...

some pumps.. usually fuel injection type of pumps.. can build well over 100 psi and when dead headed .. will slow the pump down causing it to burn out...

there are return type fuel pressure regulators to handle this..

if there is a strainer on the end of the pickup tube. is it new..or a bunch of years old???

place one of these between the tank and the pump inlet will really help..

Framhpg1

it will not only provide clean filtered fuel .. but it may help with any surge issues when you pull away from the stop and the fuel in the tank surges away from the pickup tube..

a bunch of years ago.. a friend put a blue pump on his dodge discoverer motorhome. this was to solve vapor lock issues..  the darn thing would still die.. i tried to get him to install a filter before the pump. he decided to go the other way.. and install a second pump in parallel.. well that almost worked.. you could hear the first pump start spinning faster..  then a few seconds later. you could hear the second pump spin faster.. then the engine would die..    i dropped the pumps and found them with tiny sediment pieces in them..  when he finally installed the fram fuel filter above.. there were no more issues..  except when the rev limiter on the KB556 motor got tampered with.. and during a match race. well.. how do you say.. that much stoke and 10,000 RPMs do not match for long.. KB welded a window up.. polished the crank.. replaced the aluminum rod and piston.. redid the heads.. we got more rocker arms.. and it was fixed..

but the fuel filters were the trick..

want to know another secret.. toss some magnets into the fuel tank.. they will pull any debris in the fuel system toward them.. keeping them out of the pump lines and carb..

now... as ddeello mentioned.. grounds and power supplies..

supplying the pump with enough current at full battery voltage.. not reduced ignition power.. if you are supplying it with reduced ignition voltage.. you will burn them out as they are drawing more current at reduced voltage ..

if you have a single jumper cable.. lay it out next to the car.. hook up only the positive to the battery positive..   now.. with a digital volt meter. probe between the end of the jumper cable and the positive terminal of the pump while its running..

you if your positive side wiring is properly sizes.. should have less than 1.0 volts when you measure it this way...

do the same test  negative battery post to the negative terminal on the pump again with the engine running.. again. less than 1.0 volts on the meter with it set at 20 volt scale or at 2 volt DC scale..

why .. when you touch 2 different locations with a digital volt meter. you read the difference in the voltage between those points.  if you get more than 1.0 volt you are going to have too much voltage drop and the pump will be operating at reduced voltage and drawing too much current..

please.. also take a positive to negative test at the fuel pump terminals..


there are various ways to power the pump.. so it shuts off if the engine dies.. there are oil pressure switches..  there are some very creative bosch fuel pump relays that look at the negative side of the ignition coil for signal to keep the fuel pump relay closed and the pump spinning..  these also turn on for 2 seconds when the power comes on.. but they CANNOT BE used with MSD box type ignitions. and a few other CD or CDI ignitions.. as they have several hundred volts running to the negative side of the coil. and thats enough to blow the electronics out of the relay..   almost all domestic cars use a fuel pump relay and an oil pressure switch in parallel to run the fuel pump..  if you would like more info.. just post..  

ddemello ddemello
New User | Posts: 16 | Joined: 01/14
Posted: 01/12/14
06:52 PM

hi wayne i love the motorhome story!! you give great information i see, kudos to you, and thanks.  

wayne712222 wayne712222
User | Posts: 67 | Joined: 10/13
Posted: 01/12/14
07:38 PM

oops... the KB556 was in his barracuda race car..  pulled behind the discoverer..


i actually got to meet KB on that trip to drop the short block off..

they had what looked like a crankshaft grinder with the offsetable chucks.. but instead of a grinding wheel.. it has a vertical mill head.. they would just toss a billet of 7 or 8" round stock on the machine.. and remove all that was not a hemi crank.. a machine i have always wanted since i saw it.  

ddemello ddemello
New User | Posts: 16 | Joined: 01/14
Posted: 01/12/14
09:33 PM

do you think using a water jet machine could be a good idea for doing a lot of the early work to make a billet crank? the other day i had a conversation at a taco stand with a delivery driver from tell steel out of long beach. in conversation he told me his company has a water jet machine that can cut 5 inch thick steel plate. do you think this could work?  

wayne712222 wayne712222
User | Posts: 67 | Joined: 10/13
Posted: 01/13/14
01:55 AM

that would be creative..  it would still need to be on a crank machine.. that would be a LOT of overspray when they start cutting..


they can cut 5 inch sheet..  straight thru.. and with some angles..

they can remove steel fairly fast with CNC machines..  i really don't think there would be any advantage other than having a LOT of expensive abrasive sprayed everywhere. as it sprays off the sides of the round stock.  

69_340_GTS 69_340_GTS
Enthusiast | Posts: 519 | Joined: 06/09
Posted: 01/13/14
05:20 AM

AFAIK, all electric fuel pumps should be mounted below the gas level in the gas tank. Sounds like yours is not?  

69B5Blue 69B5Blue
New User | Posts: 4 | Joined: 01/14
Posted: 01/13/14
08:04 PM

Fuel Pump Issue

Thanks to all you guys....

I sure appreciate all the input and advice......

Here is a bit more information....the car has been gone through extensively.  The build, as I told my wife, was as if I could walk into the dealership back then and just order whatever I wanted and drive away.... Only to go home and start modifying it...the block is a date coded 440 HP full roller assembly balanced and bored 30 over.  Comp cam...906 heads with 214/181 valves and a six pack on top to make me smile....MSD ignition and distributor, TTI headers with electric cut outs and a TCI Street Fighter Transmission.  The interior of this B5 Blue, black vinyl top project is all black.  Bucket seats with a buddy seat.  The steering column shift has been replaced with a consul and a B&M Star Shifter added to the floor to control getting her going.  A TicTocTach and an 8 Track tape finish the interior.  New wire by Quikwire and the battery relocated to the trunk.  New master cylinder and break lines out to Wilwood disks to shut it down.  

Last, as for the fuel system, new tank, pickup with screen as shown in the above picture and a large filter again as shown above except I have it on the discharge side of the pump in the engine bay.  I ran new 1/2" line from the tank forward with a regulator and gauge at the filter location under the hood.  As for the pumps themselves I have used the Mr. Gasket and a couple others trying to solve the problem.  I have not used the Holley Blue which will be my next move as you all suggested.  I'm also going to follow the advice of lowering the pump hight, doubling up on the wire and installing the electric shut off through the oil pressure switch and then test the volts as suggested.  Thanks again to all you guys for the help and guidance.  I'll get back and let you all know how it works out.  

ddemello ddemello
New User | Posts: 16 | Joined: 01/14
Posted: 01/13/14
09:25 PM

there is a fella at the hot rod magazine forum that is having problems with his [b-body mopar] wilwood disc brakes up front. maybe you could spare the time to talk with him and lend a hand?  

69B5Blue 69B5Blue
New User | Posts: 4 | Joined: 01/14
Posted: 01/13/14
09:41 PM

I tried to look it up but couldn't find the thread......do you have a link?  I'd be happy to try  

wayne712222 wayne712222
User | Posts: 67 | Joined: 10/13
Posted: 01/13/14
10:51 PM

http://forums.hotrod.com/70/9524696/off-topic/wilwood-disc-brakes/


if you have manual disc brakes.. could you  measure from the center of the push rod bolt.. to the side of the pivot tube.. and the diameter of the pivot tube .

and then the distance from the push rod bolt to the center of the pedal pad..

this is to see if the brake pedal he has have the correct pedal ratio..

i don't have access to any mopar pedals.. i did list a bunch of them.  but there were no measurements..

i actually talked to him on saturday night.. the pedal is HARD..  he has a 1" bore master..  it would not lock the brakes before he put the wilwood brakes on the front..  so that has me aiming toward the brake pedal ratio..  either his pedal is too short.. or it has the push bolt too far from the pivot..

i did not get a chance to ask him if they were the original 4 speed pedal set.. i realize i should have done that..  

wayne712222 wayne712222
User | Posts: 67 | Joined: 10/13
Posted: 01/13/14
11:13 PM

oh.. by the way.. if one is very creative..  one could modify the sending unit slightly.  and install a airtex E3903.. electric fuel pump.. they were designed for 85 to 87 camaros with  a carb..  




Part Number: E3903
Weight: 0.4 lbs
Warranty: Limited Lifetime
Gaskets Included: Yes
Inlet Attachement: Inlet-Strainer
Inlet Count: 1
Item Grade: OEM Standard
Maximum Free Flow Rate (gph): 35
Maximum Pressure Range (psi): 5
Minimum Free Flow Rate (gph): 20
Minimum Pressure Range (psi): 3
Outlet Attachment: Outlet-Hose Connection
Outlet Count: 1
Outlet Size: Outlet - 3/8

you will need to select a strainer for this..  and figure a way to power it thru the flange on the sending unit. not impossible for most creative people..


an FYI... here is how many gm cars and trucks are wired... don't take it as an insult.. Smile

Vortecfuelpumpwiringdia


if you want to do something like this.. i will need to find you part numbers for a 2 wire oil pressure switch . that is a switch not a sending unit..

the green wire in the diagram will usually attach to the solenoid wire so anytime the engine is cranking the fuel pump relay turns on..  the rest of the time.. the oil pressure switch handles the current.

if you wire it right.. do you see the red wire listed as fuel pump prime..

you could use a push button for that to allow you to run the fuel pump without cranking the engine..


oh... and people have also installed in tank electric fuel pumps.. on a slightly modified bulk head connector..  with the hole in the tank next to the sending unit tube.. so you can slide the whole assembly thru the sending unit opening. then come back from the inside with the bulk head connector. this only requires a nut on the outside to fasten it..  and again. so way to get power to the pump..


and using one of the scope cameras from HF or other to look inside thru the filler neck to verify placement..  

ddemello ddemello
New User | Posts: 16 | Joined: 01/14
Posted: 01/14/14
08:06 AM

thanks wayne.  

69B5Blue 69B5Blue
New User | Posts: 4 | Joined: 01/14
Posted: 01/14/14
09:36 AM

Hi Wayne,

First off, thanks from all of us...your help is keeping a lot of us pointed in the right direction and I'm sure, solving a lot of issues.

As for my breaks, I have power assisted breaks so I'm unable to take the measurements your after.  I do however talk once in a while to a guy here in town that has several a and b body cars and has been a Mopar guy since his grand dads days.....(even has grand dads original 54 Coronet he had purchased new and still looks and drives as if he bought it yesterday). Not sure if his cars are manual breaks or not but I will stop by his house today and see if he's around.  If he is, I know he'd be happy to help us pull some numbers if he is running manuals ......

I am still in the process of working through a few bugs on my 69, fuel pump being one of them as you know......as for the Wilwood breaks I put on, it included everything from the master cylinder out.....cylinder, booster, proportioning valve, lines as well as the flex line over the rear end.  I started from zero so I knew what I had.  I am very happy with them, but as I said above, still working through some bugs since I'm just getting the car on the road.  

One thing I did notice in his post is the way he worded his issue.......he says, "installed a set of Wilwoods on the front, STILL can get it to stop"..... That to me sounds like he had an issue before he started and if that's the case, maybe his issue is not caused from Wilwood.  The one thought I had after reading it was restriction.  If he has not replaced the lines and the car sat for a long period of time, he could have some hardened build up in the lines causing a restriction and thus not allowing enough fluid to fill the wheel cylinders before he runs out of peddle......also, are the lines properly sized with clean bends in them.....no kinks (more restriction).....I'm not a tech guru....but I'm a common cents (and I mean that, because 2 cents is about all it's worth most times lol) kind of thinker and it has gotten me through more than one issue.  I know it's not much, but it's worth bringing up I think...... Hope it helps and ill get back to you if John's home today and he has manuals on any of his cars.....

Thanks again for all your help Wayne....

Kevin