Which fuel pump?

[PToombs]

My fuel pump is heading south,(without the truck!) 5 psi at idle, 3 at 70 mph on the road, 0 at wot. The needle on the new gauge barely pulses with the pump. My question is will a stock new pump supply enough fuel for a set of PODs? In the spring I am going to upgrade to an HX35 and a set of PODs. My fuel screw is not in as much as it was, and may go back in farther. $50 for a stocker, or $100 for a sexy piston pump? HELP?!

 

[Bob Beauchaine]

If you're going to continue to "BOMB" your truck I would go with the piston pump. I figured that the closer I got to 400 RWHP the more likely I was to start running low on supply to my VE.



BTW I hit 417 RWHP with W/M at Diesel Thunder



Bob

 

[KrustyKruiser]

Piston pump without a doubt. No need to starve the VE of fuel for an extra 75 bucks is well worth it in my opinion.



Ian-

 

[PToombs]

That's the way I'm leaning. Scott, Bill? Any input?

I gotta get this done before SOP!

 

[Greenleaf]

Either way. I have one of each style and they both operate well. The piston pump was way overkill in my case because I seldom hot rod my truck. I don't really need 16 psi of fuel supply.

 

[dpuckett]

If I go with a piston pump, will I need to upgrade my (as of yet uninstalled) Fuel Pressure gauge? It only goes to 16psi, and I see that Bill hit 30 psi on a dyno run.



Daniel

 

[Greenleaf]

Bil is using an electric pump now to prolong the 14mm plunger/head assy. The piston pump will not make over 16 psi. It will work beautiful like.



And I would opt for the proper fuel line. One of the guys described how he put the doubble whammy to the OEM (steel ) line to make it fit. Just buy one and install it. Time is $$$

 

[bgilbert]

I vote for the sexy piston lift pump. Look to spend around $200 when all said and done. Pump itself is ~$160ish. Rest of the parts - spacer, fuel tube, 2 banjo bolt gaskets, 2 spacer gaskets will run you up and possibly over $200 total. There has been a guy on ebay selling NEW piston lift pumps that didn't pass factory quality control for $45. I bought two. One is on my 91. 5, doing fine and performing within proper specs. He's not advertising them as non passing QC pieces though. It doesn't take much to figure this out though.



GL is right, time is money, spend the $28 on the new fuel tube, be done with it.



I say don't look at it as overkill, look at it as insurance for the more expensive piece, your injection pump. Keep it supplied reliably with lube (fuel). Don't forget it's sexy. The ole lady or the girls will like your truck more with Cummins part number 3936320 bolted up to your block.

 

[Greenleaf]

not advertising them as non passing QC pieces though. It doesn't take much to figure this out though.



GL is right,

I wondered about that when a member said the LP is only 45. 00 I figured there was a catch. If I see a head stud kit for 150. 00 I think I'll pass that too.



And that is the second person to agree w/me this week alone I'm smok'n

 

[PToombs]

OK piston pump it is! The only thing is for me w/o banjo washers and gaskets it's $100 for parts. And the washers + such I have in the service truck!

Gosh, I love my job! :-laf

 

[Don Tanklage]

finally figured out you have to search 'THIS FORUM'



not 'this thread', and now i can search the archives



thanks for all this wonderful info



really appreciate it



i dont understand what all the additional parts are for when converting to a piston pump?



spacer?



fuel tube?



does anyone have pn for these items???



wish i coulda figured out how to search before i bought that new lift pump from cummins



$124 tax n gskt incl

 

[dpuckett]

The inlets and outlets for the piston pump are different from the diaphragm pump. Since it is all hard fuel line, the stuff needs to be torqued a little, or new parts installed. On a 14-18yr old truck, new stuff isnt a bad idea.



DP

 

[Don Tanklage]

what about the plastic fuel lines running the length of the truck?



do you have the pn for the piston pump?



a pn for the line from the piston pump to the filter?



the banjo fitting on the filter out side has a small plug in it on my truck



how convienent for installing a gauge



only thing is it looks like 1/8ntp



wonder if they make a gauge fitting that small?



thanks



don

 

[Leper]

Is there a part number for all the stuff needed, or does someone make a kit? This sounds like something I will be doing soon.

TIA

Leper

 

[PToombs]

Sure is!

Piston lift pump and parts needed for conversion:

- piston lift pump - 3936320 x1

- fuel line - 3914753 x1

- gasket - 3939258 x2

- spacer - 3914284 x1

- banjo bolt seals/washers - 3918191

You have to cut the plastic and insulation on the tappet cover to clear the line to the filter.





Don, Geno's garage sells a new banjo bolt that is threaded 1/8th pipe for a gauge. About $7, not worth the time to rethread the old one, been there done that. The bolt is HARD!

 

[Don Tanklage]

thanks pete



my fitting is already 1/8 pipe



definately have to put a gauge on that thing



and decide which way to go



piston pump - make my own system - fass



hummm



thanks again

 

[Leper]

Sure is!

Piston lift pump and parts needed for conversion:

- piston lift pump - 3936320 x1

- fuel line - 3914753 x1

- gasket - 3939258 x2

- spacer - 3914284 x1

- banjo bolt seals/washers - 3918191

You have to cut the plastic and insulation on the tappet cover to clear the line to the filter.

Excuse my noobness, but are those Cummins numbers, or part store numbers?

 

[Don Tanklage]

i am thinkin cummins pn's



and i take it the pump exit takes a banjo instead of the pipe fitting that is on the end of the stock fuel line?



what about the inlet side of the pump?



what is there?



don

 

[cerberusiam]

i am thinkin cummins pn's



and i take it the pump exit takes a banjo instead of the pipe fitting that is on the end of the stock fuel line?



what about the inlet side of the pump?



what is there?



don

Yes, pump exit is a banjo and a little different shaped line than the OE pump. The inlet side uses the same quick detach fitting as the OE pump.



FYI, you will need to trim the insulation on the rocker cover to get the pump and lines to fit. (Don't remeber if this was mentioned)

 

[PToombs]

The pump exit type is the same as the stocker, the line is different because the shape of the pump is different.



Cummins part #'s.



If you have a Case dealer nearby, change the 1st 3 to a J. You can get parts there.

(I think I typed that 4 times today on different sites! )