Lift pump replacement

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seabreeze331

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Joined
Feb 17, 2010
Posts
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Location
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So, here we go again.

Coming from Fl to NC, pulling the hills along I20 was very sluggish. With the big truck in tow and it carring a 25ft freezer I figured I was heavy. Then it dawned on me that I have 400 puppies pushing me and little or no wind on the toad.
Even dropping the truck I have problems pulling small inclines.
The service engine light came on when I left but it was cold and I had a time getting it started.

I'm thinking the lift pump isn't putting in enough fuel with power demand.
Flat running is great, it's just when I demand more power.
Any idea's before I spend $280.00 for a pump?

Thanks
 
If you have a  Cummins ISC the lift pump only operates for about 30 seconds when you turn on the key to start the engine. It is designed to prime the fuel system and does not continue to run after the initial prime sequence. I would look for another cause.
Hope this helps.
Pete
 
I've got the ISL400 with an electric transfer pump.

Best I understand, it increases pressure as the demand for power increases.
The filter is changed each year and has just been changed last week. The problem was there, I just didn't see it as a power problem. And remained after the filter was changed
 
My DP has two Fuel Filters, does yours and did you change both?????
 
I would suspect a clogged inlet on the lift pump. Algae growth in the full tank is one common cause of that.  You have to remove the lift pump to see, tho, so the labor is the same as replacing the pump.  Photo below shows what can happen.

A dirty air filter will have the same symptoms. So will a non-performing Charge Air Cooler, e.g. a leak in the intake that lets hot air in.
 

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Only one filter for this beast. There was clean fuel in the filter removed and no sign of contamination at all.

Not sure how to check the charge air cooler lines but I'll go break something.


 
JPete, your'e right that the transfer pump "primes" and then is out of the circuit. This was a high price troubleshooting start but there were other codes that supported changing the pump.

Once the engine codes were cleared, only 28 018 11 came back.
According to cummins, this is a code for the wireing harness for the fuel solenoid.
Theres nothing I like better than chaseing a wire grimlin. But for now I'll have to leave it here and return in April to finish.

 
Still feels like a fueling issue to me. I chased one for two years before I figured it out. Did Cummins check out the fuel pressure coming from the high pressure injector pump? It is an expensive piece but may explain the power issue when there is high demand. Not sure if the engine computer would send a code if there was a pressure issue.

Good luck.
Pete
 
The Eagle has landed.
We're at home base and came across the I20 hills that took my ISL400 to her knees like they were flat as pancakes. She makes great power now.

After changeing the lift pump didn't seem to fix the problem, all wires and connections for the fuel control system was checked. No fault was found and the codes did not return. After a 1/2 tank of test run with three different trips it was concluded:
1. Lift pump really did fix it and just needed to be purged real good.
2. Pulling apart and reconnecting plugs made a better connection.
3. It really likes the NC BBQ and wanted to stay.

Anyway, I'm a bit poorer but am a happy camper. Even if they did replace both chassis batteries.
 
Good to hear it is running well again.

Mine seems less powerful than it was 3-4 years ago, but I'm not ready to pop for a lift pump  (yet). Mine also seems sensitive to air intake - had to change the big air filter even though the "filter minder" still' said it was fine. The new filter was a $100+ gamble that paid off.
 

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