It's 10pm - where's your lift pump?

racertracer · **Posted:** Mon Apr 30, 2012 9:23 pm

altdiesel wrote:

I am gong to do this mod soon, and I have read everything in this post, also all the other posts about going with an Airtex lift pump.

What is the recommended part number? I have seen three being talked about:

E7181M less flow, 15.95 psi

OR

E7187M more flow, 11.6 psi

So... It looks like both are still available, just what one to go with is the question. Would love to hear feedback from people who have one or the other.

Correct me if I'm wrong but some time ago the proper PSI for our fuel delivery system was discussed and it was determined that no more than 4.7 psi would be sufficient to prevent damage to the high pressure pump down the line.

altdiesel · **Posted:** Mon Apr 30, 2012 10:39 pm

racertracer wrote:

altdiesel wrote:

I am gong to do this mod soon, and I have read everything in this post, also all the other posts about going with an Airtex lift pump.

What is the recommended part number? I have seen three being talked about:

E7181M less flow, 15.95 psi

OR

E7187M more flow, 11.6 psi

So... It looks like both are still available, just what one to go with is the question. Would love to hear feedback from people who have one or the other.

Correct me if I'm wrong but some time ago the proper PSI for our fuel delivery system was discussed and it was determined that no more than 4.7 psi would be sufficient to prevent damage to the high pressure pump down the line.

I hope that is not the case, seeing how I just ordered from RockAuto the E7181 Cummins pump, that flows 15.95 PSI.

Anyone else know what the correct pump is?

msilbernagel · **Posted:** Tue May 01, 2012 12:29 am

There was an extended discussion on this topic in the TDR (Dodge diesel) forum years ago. The Dodge Cummins use an almost identical version of the Bosch CP3, except that the first stage of those pumps raise the internal pressure to the 70+ PSI range while (from recall) our VM diesels use a version of that pump that runs in the 40+ PSI range.

I've never heard of failures due to pressures (period) and while there's been a lot of discussion on the merits of 9PSI .vs. 18PSI I think the primary goal is to have at least a few PSI coming out of your fuel filter under worst-case conditions (time to replace the filter) and full fuel flow. If the pump and filter can maintain at least 0 PSI at full flow the CP3 will do all the rest of the work without issues.

As I recall, the stock in-tank pump in the pickups delivers about 9PSI.

Our suburban has the 04.5 model year Cummins with CP3, and I've run aftermarket fuel pumps that seem to peak at 15-18 PSI with a fresh filter @ idle (best case) - never any issues with over 100k miles so far.

Personal speculation considering all I've read and experienced is that you will not see any issues under 20PSI; you could probably go higher but there would be no point. I believe most of the Cummins users regularly run 18PSI, which is the default on a lot of the aftermarket pumps.

These things are tough and not apparently sensitive to wide ranges input fuel pressure.

By the way, I highly recommend using some sort of coarse pre-filter ahead of the pump to protect it from common junk; sand, gravel, flaked paint, organic debris, etc. If you don't, you'll find yourself thinking you need a replacement pump in a year's time - only to find that the internal screens are impacted with the stuff and causing the pump to cavitate. Your primary filters will last a lot longer too.

Mark

racertracer · **Posted:** Tue May 01, 2012 6:52 am

In the past I remember reading posts from three different members, that had to replace their CP3 due to no start issues and although none of them attributed the fault to the in tank fuel pump all three of them had an in tank pump installed.

If the in tank fuel pump has enough force to push through and dislodge particles from a neglected, dirty, or clogged fuel filter, you can expect damage to the CP3. I agree with the thought of installing an additional filter when adding an in tank fuel pump, or replacing the OEM fuel filter sooner rather than later.

altdiesel · **Posted:** Tue May 01, 2012 9:46 am

How do you install a pre-screen filter on an internal tank mounted pump? The pump I purchased looks identical to the sending unit currently in the tank.

Sir Sam · **Posted:** Tue May 01, 2012 12:51 pm

altdiesel wrote:

How do you install a pre-screen filter on an internal tank mounted pump? The pump I purchased looks identical to the sending unit currently in the tank.

You don't, the replacement unit has a pre-screen on it. thats plenty sufficient.

msilbernagel · **Posted:** Tue May 01, 2012 3:28 pm

The pre-screen filter was for inline pumps, as is the case on our Suburban w/Cummins...

The in-tank units have a 'sock' that serves the purpose.

Mark

msilbernagel · **Posted:** Tue May 01, 2012 4:28 pm

racertracer wrote:

In the past I remember reading posts from three different members, that had to replace their CP3 due to no start issues and although none of them attributed the fault to the in tank fuel pump all three of them had an in tank pump installed.

I agree with the potential for problems inherent in going beyond what is necessary, pressure-wise.

Since the CP3 is happy pulling a vacuum, wisdom would argue that as long as your lift pump can maintain single digit pressures under WOT with a filter nearing service limits - you're safer than using higher pressures and potentially damaging the upstream filters or worse still the CP3 itself (or even injectors if the filters fail).

On the Cummins I can tell when the filter is nearing end-of-life just by watching post-filter fuel pressure while driving; how it handles transients and the average fuel pressure at cruise.

altdiesel · **Posted:** Wed May 02, 2012 9:29 am

So it appears from reading the last 3 posts, using a pressurized in tank pump, is not a good idea. After reading about air in the lines, I think this is the best solution to the problem. After reading this, http://www.auerbach.ca/kj/lift_pump/, it still looks like the best option. Which is funny, because I am posting the link to this thread in of itself.

Basically I just want to do all the lost jeep tricks, so I can be assured that my wife will not have any issues diving her Jeep.

bugnout · **Posted:** Wed May 02, 2012 11:34 am

altdiesel wrote:

So it appears from reading the last 3 posts, using a pressurized in tank pump, is not a good idea. After reading about air in the lines, I think this is the best solution to the problem. After reading this, http://www.auerbach.ca/kj/lift_pump/, it still looks like the best option. Which is funny, because I am posting the link to this thread in of itself.

Basically I just want to do all the lost jeep tricks, so I can be assured that my wife will not have any issues diving her Jeep.

Definitely the best MOD I've ever done. Should have come from the factory with an intank lift pump. Its obvious that DC intended for a lift pump and some wanker cost cutter decided that it would do just fine with the CP3 intake sucking from the tank. That guy should be made to drive a Yugo for the rest of his days...

I think the discussion was more about what kind of pressure is needed and if excess pressure can harm the fuel system. My personal oppinion is that you only need minimal positive pressure to the fuel head, 4 or 5 psi, to completely resolve this issue.

altdiesel · **Posted:** Wed May 02, 2012 1:16 pm

bugnout wrote:

altdiesel wrote:

So it appears from reading the last 3 posts, using a pressurized in tank pump, is not a good idea. After reading about air in the lines, I think this is the best solution to the problem. After reading this, http://www.auerbach.ca/kj/lift_pump/, it still looks like the best option. Which is funny, because I am posting the link to this thread in of itself.

Basically I just want to do all the lost jeep tricks, so I can be assured that my wife will not have any issues diving her Jeep.

Definitely the best MOD I've ever done. Should have come from the factory with an intank lift pump. Its obvious that DC intended for a lift pump and some wanker cost cutter decided that it would do just fine with the CP3 intake sucking from the tank. That guy should be made to drive a Yugo for the rest of his days...

I think the discussion was more about what kind of pressure is needed and if excess pressure can harm the fuel system. My personal oppinion is that you only need minimal positive pressure to the fuel head, 4 or 5 psi, to completely resolve this issue.

Thanks for your personal input and experience! What pump did you go with? From what I read, these are really the only two options for an in-tank pump:

E7181M less flow, 15.95 psi

OR

E7187M more flow, 11.6 psi

bugnout · **Posted:** Wed May 02, 2012 2:18 pm

altdiesel wrote:

Thanks for your personal input and experience! What pump did you go with? From what I read, these are really the only two options for an in-tank pump:

E7181M less flow, 15.95 psi

OR

E7187M more flow, 11.6 psi

Don't remember, I ordered 5143160AA, from Mopar parts america I'll check when I get home to see what I actually got, I was in the first group that performed this mod. At the time only one part number had been identified.

msilbernagel · **Posted:** Wed May 02, 2012 2:42 pm

bugnout wrote:

Definitely the best MOD I've ever done. Should have come from the factory with an intank lift pump. Its obvious that DC intended for a lift pump and some wanker cost cutter decided that it would do just fine with the CP3 intake sucking from the tank. That guy should be made to drive a Yugo for the rest of his days...

I think the discussion was more about what kind of pressure is needed and if excess pressure can harm the fuel system. My personal oppinion is that you only need minimal positive pressure to the fuel head, 4 or 5 psi, to completely resolve this issue.

Yes - I'd be hard pressed as to 'best' but the in-tank pump and SEGR are definitely 1 and 2..

And Yes - perfect summary re: modest fuel pressures.

Mark

altdiesel · **Posted:** Wed May 02, 2012 7:41 pm

Thanks Bungout for your response!

bugnout · **Posted:** Wed May 02, 2012 10:19 pm

altdiesel wrote:

Thanks Bungout for your response!

Thought I still had the packaging. Sorry. I did look up that part number and it appears to be for a 2008 Dodge 2500 34 gallon tank.

Squeeto · **Posted:** Wed May 02, 2012 10:45 pm

altdiesel wrote:

E7181M less flow, 15.95 psi

OR

E7187M more flow, 11.6 psi

I don't think that the E7187M fits. It has that extra gray vent on top and no tab for alignment.
As far as I remember, no one has said that they installed the E7187M yet.

The original, now impossible to get Dodge part was 5143160AA. Someone here determined that it was an Airtex E7181M.

My truck used to cough and wheeze because of air in fuel but 3 years with a lift pump and not a single incident. I installed the 5143160AA.

Also, the truck comes pre-wired for a lift pump so DC must have considered putting one in.
As for the pressure, we will have to see how long the CP3 pump lasts. I don't care to worry. Without the lift pump, the wife broke down on the highway with a load of groceries. Bye, bye :JEEPIN:

altdiesel · **Posted:** Thu May 03, 2012 12:42 am

Squeeto wrote:

altdiesel wrote:

E7181M less flow, 15.95 psi

OR

E7187M more flow, 11.6 psi

I don't think that the E7187M fits. It has that extra gray vent on top and no tab for alignment.
As far as I remember, no one has said that they installed the E7187M yet.

The original, now impossible to get Dodge part was 5143160AA. Someone here determined that it was an Airtex E7181M.

My truck used to cough and wheeze because of air in fuel but 3 years with a lift pump and not a single incident. I installed the 5143160AA.

Good point. Today, the jeep quit on me after the cel came on. I knew the heater head plug was bad, but now it is dead. I was left stranded on the road and had to call a tow. I took it to my friends shop and had them use there snapon computer scanner. It said fuel air leak, not sure what code. Anyway, I have a new heater head ordered and plan on doing the lift pump install ASAP. I also ordered a pair of Samcos, and plan on doing the EHM, and GDE hot tune soon.

Also, the truck comes pre-wired for a lift pump so DC must have considered putting one in.
As for the pressure, we will have to see how long the CP3 pump lasts. I don't care to worry. Without the lift pump, the wife broke down on the highway with a load of groceries. Bye, bye :JEEPIN:

Carterhouch · **Joined:** Mon Mar 25, 2013 12:47 pm **Posts:** 4

Help just installing lift pump everything went OK until I tried to test pump before putting tank back up in place. Pump did not work I checked for power at 10 pi connector under seat but no power at pin # 2 when turn key on. I checked for fuse and relay labeled fuel prime and they are in place. Any advice? 2005 crd

msilbernagel · **Posted:** Wed Mar 27, 2013 7:22 pm

You can use a straight pin to push through the insulation on the wires, and check voltage at the relay (front/driver side relay box). It's probably challenging to trace back from there - guessing it goes through the firewall and under the carpets. Make sure you have a good ground for the tester, too.

FYI - mine (2005) had power there the whole time, so by default it gets that far.. (all things being equal).

Carterhouch · **Joined:** Mon Mar 25, 2013 12:47 pm **Posts:** 4

Found problem there was a broken wire( Blue with red stripe) under carpet on drivers side. Thanks for all the posts jeep runs much better

It's 10pm - where's your lift pump?

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