AMC Eagle Den Forum

The Mighty 258 => Fuel Systems. => Topic started by: Nightpath on June 12, 2014, 07:24:46 AM

Title: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: Nightpath on June 12, 2014, 07:24:46 AM
Howdy all,

Some time this summer I'll be changing my engine from the 4.2 to a 4.0, with the transmission and t-case (w00t).

Anyways, I've been debating modifying the 4.0 pump to fit into the Eagle tank, or just using a inline fuel pump. To me, the inline fuel pump mounted underneath is the best bet. If it goes bad I can easily replace it without dropping the tank, which in the winter here in Canada is a real bag of dicks.

Either way, I have to buy a pump.

Anyone have any suggestions? Or experience in this?
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: eaglefreek on June 12, 2014, 10:05:57 AM
My V8 Eagle has an inline pump. It does an ok job until I get to about 1/4 tank. It will starve when taking off fast or making a left turn. I thought about installing a surge tank. Basically, it's a smaller tank that is fed by a  low pressure pump and then the high psi pump pulls from the surge tank. http://www.superstreetonline.com/project_car/ssts_1119_building_a_fuel_surge_tank/ I know a couple people that have installed tehm in SX4 tanks, but I think they are a different shape than the wagon. The wagon tank has a wedge shape in the front that might make it difficult to install an intank pump.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: DaemonForce on June 12, 2014, 12:44:00 PM
Chiming in to vote for inline pump. There is just too much about this car that centralized everything in the worst spots. You do not want to go through the trouble of draining, tank straps, dropping the tank and so on whenever you have fuel pump issues. Might as well get the sending unit issues out of the way while you're there though. :blob1:
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: carnuck on June 12, 2014, 01:23:16 PM
In my wagon I plan to stick the XJ tank with pump in and add a new fill hole to the tank with that part from an Eagle tank and cap off the old one. We did a test fit with the rear frame from the wagon we parted.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: BenM on June 12, 2014, 02:38:34 PM
In tank pump, because you should drop the tank and inspect it anyway. Also, most inline pumps are impeller pumps and not good at drawing but are good at pressurizing, which is why they're placed in the tank.

Mechanical pumps do a good job of drawing fuel up as long as they don't have to lift too far (over 30 feet). They do make electric pumps designed for positive displacement, you just have to look specifically for them.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: carnuck on June 12, 2014, 03:01:14 PM
In tank pump is cooled by the liquid gasoline too. I won't need a pump when I go LPG because I run a vapor system until I can afford LPG-EFI which will be a special tank with built in pump.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: Nightpath on June 12, 2014, 09:07:11 PM
They cost about the same anyways don't they?
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: eaglefreek on June 12, 2014, 11:06:15 PM
Yes they are usually about the same price, depending on which pump you choose. There are some real expensive ones that include a baffle. An intank is usually a better option than an inline, however it may be difficult to install one in an Eagle tank. With an intank pump, you should have some type of baffling to keep the fuel from sloshing past the pickup. 
http://www.tanksinc.com/index.cfm/page/ptype=product/product_id=84/mode=prod/prd84.htm
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: Draekon on June 13, 2014, 02:19:19 AM
Yes they are usually about the same price, depending on which pump you choose. There are some real expensive ones that include a baffle. An intank is usually a better option than an inline, however it may be difficult to install one in an Eagle tank. With an intank pump, you should have some type of baffling to keep the fuel from sloshing past the pickup. 
http://www.tanksinc.com/index.cfm/page/ptype=product/product_id=84/mode=prod/prd84.htm

Sloshing is just as much of a problem with an in-line pump as it is with an in-tank pump.  Inline pumps dont like sucking any air
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: Nightpath on June 13, 2014, 06:22:35 AM
I won't be doing any crazy stuff with the car. Highway driving and back and forth to work. Possibly a bit of dirt road cruising.

So the benefit of modifying the XJ pump to fit the Eagle tank would be that the fuel keeps the pump cool right? And it grabs the gas to send better?

I would think that an inline pump would accommodate for temperature.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: carnuck on June 13, 2014, 01:01:16 PM
Inline pumps burn out more often than in tank ones do *except Chev pumps*
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: Nightpath on June 13, 2014, 04:30:10 PM
Is there a Chevy inline that would work?
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: eaglefreek on June 13, 2014, 06:21:00 PM
I think he is inferring that Chevy intank pumps burn out more frequent than others.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: Nightpath on June 15, 2014, 06:49:09 AM
Lol. :censored: chevy crap.

Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: carnuck on June 15, 2014, 07:00:44 AM
Lol.  chevy = crap.



FIFY
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: captspillane on June 16, 2014, 06:57:53 PM
Inline pumps are horrible. I have a Hesco MPI kit and a Howell TBI kit, and both used inline pumps on the transmission skid plate. They both suck horribly and I will never use another inline pump again.

They burn out about once a year because they don't cool well and are very fragile to filtration.

Hesco wants $140 for a replacement. A comparable in tank pump costs about $30 if you order a stock unit off Rockauto and adapt it to the AMC pickup tube.

They are very very loud and annoying.

If you run out of gas you must unplug the input line and let gas flow out all over the place until the air is gone and you can push the line back on the pump while cursing. The inline pumps cannot prime themselves even if you top the gas tank off completely.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: Baskinator on September 29, 2014, 06:24:13 PM
FYI, someone on here rigged up a GM in-tank fuel pump to fit in the Eagle tank easily through the sender area. The tank would not need to be dropped to replace it, and the pumps cost less than $20. Baffling may still be an issue, but it could potentially be remedied with some creative work.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: Nightpath on November 03, 2014, 09:13:21 PM
Do you know who? I've hit a huge hurdle...forgot about the fuel pump and listened to some :censored: that said an XJ one would fit right in there. Now I'm cornholed, tank is off and I'm running out of money.

What's a cheap solution to get my fuel injection working?
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: carnuck on November 04, 2014, 12:45:25 PM
If you have a wagon, I'm planning to put the whole XJ tank in mine with the original fill blocked off and the Eagle filler grafted to the tank. Aside from that, there is a Holley external pump I can't recall the number of that works. Did you add a return line already or mod the vapor return line to work?
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: eaglefreek on November 04, 2014, 07:09:18 PM


What's a cheap solution to get my fuel injection working?
Inline pump.
Title: Re: Changing to 4.0L drivetrain : In tank pump or inline?
Post by: amchornet on November 18, 2014, 06:35:22 AM
   You have to modify the stock zj pump to do this but it will work as you can see. I have used a zj pump off a 93 and also a 95 pump off an xj. They both required some minor modification to get into the tank.

(http://i12.photobucket.com/albums/a228/amchornet/Mobile%20Uploads/IMG_20140622_130701_291_zpskjforvcl.jpg) (http://s12.photobucket.com/user/amchornet/media/Mobile%20Uploads/IMG_20140622_130701_291_zpskjforvcl.jpg.html)(http://i12.photobucket.com/albums/a228/amchornet/Mobile%20Uploads/IMG_20140622_150553_301_zps3psqtdns.jpg) (http://s12.photobucket.com/user/amchornet/media/Mobile%20Uploads/IMG_20140622_150553_301_zps3psqtdns.jpg.html)(http://i12.photobucket.com/albums/a228/amchornet/Mobile%20Uploads/IMG_20140622_150531_266_zpseq7hnj5k.jpg) (http://s12.photobucket.com/user/amchornet/media/Mobile%20Uploads/IMG_20140622_150531_266_zpseq7hnj5k.jpg.html)