I've installed a 2001 5.2 Magnum in my 68 Barracuda. I would like to use an in-tank unit with the old sending unit and pickup. Looks like pressure needs to be somewhere around 85-110 psi. That's from Rock Auto Airtex pump for 2001 Ram truck. Any suggestions?
Electric fuel pump - Which one?
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BillGrissom
Well-Known Member
I don't think MPFI runs that high, more like 55 psi max. I think the 2001 Magnum engines were a "return-less" design where the fuel pressure is regulated right in the tank, with only a single tube to the engine. That was a federal mandate that started about then. The in-tank pump is a big assembly w/ fuel sender. Not sure how you could fit that in your A-body tank. An external fuel pump and regulator seems more tractable. Best if the regulator is closer to the engine's fuel rails (built-in on earlier Magnums), but you could put it right after the fuel pump, with a return line back to the tank. Read up here for what others have done. Many modders use the Corvette filter/regulator, I did ($20 O'Reilly's).
Mad Dart
Nothing to see Here!
If you are trying to use the factory pick up & Sending unit you will be modding most of it yourself. Pick up a Walbro in tank pump and start fabbing. There was a member on here that did it awhile back. I don't remember who it was though.
[ame="http://www.ebay.com/itm/Genuine-Walbro-255-LPH-High-Pressure-In-Tank-Electric-Fuel-Pump-Universal-GSS342-/281269541941?pt=Motors_Car_Truck_Parts_Accessories&hash=item417cf89c35&vxp=mtr"]Genuine Walbro 255 LPH High Pressure in Tank Electric Fuel Pump Universal GSS342 | eBay[/ame]
[ame="http://www.ebay.com/itm/Genuine-Walbro-255-LPH-High-Pressure-In-Tank-Electric-Fuel-Pump-Universal-GSS342-/281269541941?pt=Motors_Car_Truck_Parts_Accessories&hash=item417cf89c35&vxp=mtr"]Genuine Walbro 255 LPH High Pressure in Tank Electric Fuel Pump Universal GSS342 | eBay[/ame]
When I did FAST fuel injection on my Duster,it was with the corvette pump attached to the sender/pickup tube and made a 1/4'' return fitting mounted in the plate of the sender/pickup. I had 38 lbs injectors.Find out what lbs injectors are in the 5.2 and get a pump that will have a higher (like 55 lbs) pressure to fire the injector.The local autoparts store hooked me up with a fitting that was threaded pass thru with a gasket seal for the return.Sorry I don't have a photo as it was 12 years ago and the car is long gone. Just a thought.
Thanks Guys - I looked in the FSM and found the correct pressure. I always forget to look there. Looks like this fuel pump, sending unit, regulator and filter are all integral to the fuel tank.
Here is a link to a fuel pump on Rock Auto. This is a replacement pump for the fuel tank unit on the 2001 truck. I'm thinking- why couldn't I attach this pump (or the Walbro) to the metal pickup on my original sending unit inside the tank. I could the place a fuel regulator outside the tank with a return fuel line. That way I'm sending approx 50-60 psi through the metal fuel line to the fuel rail. If there is such a thing as an adjustable regulator, test and adjust the fuel pressure at the fuel rail. This could also compensate for an inline filter and any pressure drops.
Tell me if I'm totally off base on this. It just seems to me that this would be better than having to put a sump in the bottom of the tank or replacing the original tank with a fuel cell.
Rock Auto replacement pump for 2001 Ram 1500 fuel Module:
http://www.rockauto.com/catalog/moreinfo.php?pk=3097185&cc=1366589
FSM procedure to test 2001 Ram 1500 fuel pressure:
(2) Start and warm engine and note pressure
gauge reading. Fuel pressure should be 339 kPa +/- 34
kPa (49.2 psi +/- 5 psi) at idle.
Here is a link to a fuel pump on Rock Auto. This is a replacement pump for the fuel tank unit on the 2001 truck. I'm thinking- why couldn't I attach this pump (or the Walbro) to the metal pickup on my original sending unit inside the tank. I could the place a fuel regulator outside the tank with a return fuel line. That way I'm sending approx 50-60 psi through the metal fuel line to the fuel rail. If there is such a thing as an adjustable regulator, test and adjust the fuel pressure at the fuel rail. This could also compensate for an inline filter and any pressure drops.
Tell me if I'm totally off base on this. It just seems to me that this would be better than having to put a sump in the bottom of the tank or replacing the original tank with a fuel cell.
Rock Auto replacement pump for 2001 Ram 1500 fuel Module:
http://www.rockauto.com/catalog/moreinfo.php?pk=3097185&cc=1366589
FSM procedure to test 2001 Ram 1500 fuel pressure:
(2) Start and warm engine and note pressure
gauge reading. Fuel pressure should be 339 kPa +/- 34
kPa (49.2 psi +/- 5 psi) at idle.
longarm
Car sold back to original owners
A couple threads that might help.
http://www.forabodiesonly.com/mopar/showthread.php?t=181027
http://www.forabodiesonly.com/mopar/showthread.php?t=48163
http://www.forabodiesonly.com/mopar/showthread.php?t=181027
http://www.forabodiesonly.com/mopar/showthread.php?t=48163
Mad Dart
Nothing to see Here!
You can buy whatever you want from a Vendor. Plenty of Walbro out there!
BillGrissom
Well-Known Member
Some have put a Walbro "external" pump inside the fuel tank by putting it on rubber hose attached to the end of the sender pickup. The reason is not to eliminate the need for a sump (how would that help?), but to minimize suction problems for the fuel pump. Seems like a lot of work (running wires), since an external pump works fine, especially if you use a 3/8" sender. I don't like mixing gasoline, custom wiring, and high-energy devices like fuel pumps.
Unless you have a special sump tank, you will get sloshing and starve the fuel pump momentarily when you brake hard, but the A-body tank isn't bad since it is kind of like a sump design already. My 65 Newport w/ a big, flat tank does slosh a lot, so I try to keep above 1/4 tank.
No big deal if you get another 5 psi drop between your regulator and fuel rails, and even if the drop varies. The computer can quickly compensate, based on the O2 sensor. Indeed, the current in-tank regulators don't compensate for intake manifold pressure like most older rail-mounted ones do. Why should they? The computer measures Pman and can instantly adjust injector pulse width to compensate, rather than trying to maintain constant dP across the injectors.
Unless you have a special sump tank, you will get sloshing and starve the fuel pump momentarily when you brake hard, but the A-body tank isn't bad since it is kind of like a sump design already. My 65 Newport w/ a big, flat tank does slosh a lot, so I try to keep above 1/4 tank.
No big deal if you get another 5 psi drop between your regulator and fuel rails, and even if the drop varies. The computer can quickly compensate, based on the O2 sensor. Indeed, the current in-tank regulators don't compensate for intake manifold pressure like most older rail-mounted ones do. Why should they? The computer measures Pman and can instantly adjust injector pulse width to compensate, rather than trying to maintain constant dP across the injectors.
One thing to be careful of with external fuel pumps is that the hose between the pump and the tank is under vacuum. That lowered pressure on the fuel will allow/encourage it to boil and vapor lock in hot weather conditions. Off roaders run into this semi-frequently with late model engine swaps, but street cars aren't immune. A more rigid than normal hose, or reducing the actual hose length to the bare minimum, is a good idea.
I understand what you are saying about electric wires and gasoline! While it is now common practice, it still seems to me to be a recipe for disaster.
If there is no problem picking up the fuel with the external pump, I have no problem going that way. The Corvette filter/regulator seems to be the ideal solution for the pressure. No longer costs $20, though!
If there is no problem picking up the fuel with the external pump, I have no problem going that way. The Corvette filter/regulator seems to be the ideal solution for the pressure. No longer costs $20, though!
Flammability Limit <- wiki link; from link:
According to Bechtold's SAE published book "Alternative Fuels Guidebook" the LEL of gasoline is 1.4% by volume and the UEL is 7.6% by volume.
So long as the vaporized fuel in the tank is not within that narrow range it isn't explosive, it won't even burn. I know that I just ruined a lot of movies.
Even if it does somehow manage to be within that narrow range it still needs a spark. While 12 VDC can spark, it usually needs a LOT of current to happen. Only other way is a lot of voltage, and the only way to get that at the fuel tank is static.
Normal Engineering practice would first require determining how often, if ever, the concentration of fuel vapors in the fuel tank is within the flammable window. To satisfy the Feds (FMVSS) that would have to be well researched and documented. Then any potential (sorry) source of static charge would have to be removed. All of this during every conceivable scenario including the most violent of collisions before the Feds would allow it (call this the "Pinto Lessons").
In-tank pumps aren't any particular concern to me. What does worry me is home built fuel systems with no means to automatically kill the pump in the event of an accident. Catch the car on fire and the last thing that you need is the fuel pump still pumping fuel into the fire. EFI computers handle this, but without something like an oil pressure kill switch in the pump's wiring a carb'd vehicle has nothing.
wikipedia said:
According to Bechtold's SAE published book "Alternative Fuels Guidebook" the LEL of gasoline is 1.4% by volume and the UEL is 7.6% by volume.
So long as the vaporized fuel in the tank is not within that narrow range it isn't explosive, it won't even burn. I know that I just ruined a lot of movies.
Even if it does somehow manage to be within that narrow range it still needs a spark. While 12 VDC can spark, it usually needs a LOT of current to happen. Only other way is a lot of voltage, and the only way to get that at the fuel tank is static.
Normal Engineering practice would first require determining how often, if ever, the concentration of fuel vapors in the fuel tank is within the flammable window. To satisfy the Feds (FMVSS) that would have to be well researched and documented. Then any potential (sorry) source of static charge would have to be removed. All of this during every conceivable scenario including the most violent of collisions before the Feds would allow it (call this the "Pinto Lessons").
In-tank pumps aren't any particular concern to me. What does worry me is home built fuel systems with no means to automatically kill the pump in the event of an accident. Catch the car on fire and the last thing that you need is the fuel pump still pumping fuel into the fire. EFI computers handle this, but without something like an oil pressure kill switch in the pump's wiring a carb'd vehicle has nothing.
NTW Ntsqd - I agree 110% about the safety shutoff issues. Don't know yet if the PCM and fuel pump relay for the Ram handles this, but a manual toggle switch and PS-64 oil pressure shutoff switch are already on order. I'm also considering finding an inertia switch from an old Ranger for a safety shutoff.
A manual toggle switch would be more for anti-theft or maintenance, not safety.
The last thing I want is to be working on the car in the garage and suddenly you are standing in a huge puddle of gasoline. I have been there and it is a scary situation.
A manual toggle switch would be more for anti-theft or maintenance, not safety.
The last thing I want is to be working on the car in the garage and suddenly you are standing in a huge puddle of gasoline. I have been there and it is a scary situation.
Something like this may help you out.
http://www.tanksinc.com/index.cfm/p...category_id=61/home_id=-1/mode=prod/prd84.htm
http://www.tanksinc.com/index.cfm/p...category_id=61/home_id=-1/mode=prod/prd84.htm
No familiarity with MOPAR ECU's, but both of the others ECU/PCM's have control of the fuel pump relay (FPR) so that they can run the pump during cranking. I am under the impression that they also turn the FPR off when they either don't see a signal for the cam or crank sensor(s) or from the oil pressure sensor. Wouldn't surprise me if the MOPAR ECU also has control of the FPR, and if it does there will be some sort of safety control subroutine in it's programming.
Expanding on this for future reference. The reason for a a more rigid hose on the suction side is because most fuel hose is rated for pressure, not vacuum. I've had some hoses collapse under pump vacuum. They usually won't do it when new, it takes a while for them to break-down or what ever it is that happens. My guess is that the newer, "low emissivity" type EFI hose (SAE 30R9) will stand up to vacuum better than older hose types due to the type of liner used in this hose (PE? PTFE?), but at this point it is only a guess under testing. I am running a Walbro 392 pump (~15 psi version) externally with the low emissivity hose to support the current carb (by-pass regulator) and the eventual TBI on my Valiant's 170.
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