Lift pump options for an 07.

[MBuechle]

I believe the lift pump on the truck in my sig is getting week. In cold weather as I get 6-7 miles down the freeway, I see my CP3 inlet fuel pressure drop from 7 to 2 or less depending on temp. At 2 the rail pressure will begin to sag from 19k to about 10 -12k depending on load and temp, then I get a check engine light with a P0148 code. I have a BF1212 and a Donaldson 3131515 mounted on the frame just ahead of the tank. Both are heated and insulated. Last winter I only had one filter heated and was good down to single digits. This year I have problems any thing below 30f. Also noticed lower pressure last fall, changed filters but no real change in pressure. The lift pump could vary well be original, the truck has 240k on it. My question is, who makes a better in tank pump? Geno's has the Carter, Rock auto has Airtex, Delphi, Carter and some others. Summit has a Fleece but at $750 I think I'll pass. Engine is stock 'cept for the Bullydog. Experience?

 

[AH64ID]

Are you sure the heaters are working? That sounds like classic gelling.

 

[Ozymandias]

Replace with factory if needed, you'll have a hard time to get a quarter million miles out of an aftermarket pump.

 

[MBuechle]

Are you sure the heaters are working? That sounds like classic gelling.

My thoughts also and initially the single heater wasn't. The cheep Chinese thermostat controlling the relay quit. Tapped into the factory filter heat wire for relay coil control. Added a 100 watt heat blanket to the Donaldson filter, closed the bottoms of the filter coozies. That helped but not like it should have. got me maybe 3 more miles down the freeway. Don't know if the factory heater is working or not. Tried Power Service anti gel, no noticeable difference. I'm also seeing the inlet pressure tank while accelerating to merge and it runs a couple pounds lower climbing out of the Kalamazoo river basin on I94. That's the place I use to gauge when my filters need changing, usually 5-6psi, now 4-2. That's in warmer weather. Last winter with a heater on the Baldwin only I could maintain 4psi down into the low teens temperature wise. This year with both filters heated I'm at 3-4psi in the mid twenties. I don't know what kind of pump this is, centrifugal, vane, gearotor? Is it a brushed motor? Key on before start I see 8psi static, 7 driving around town, 6-7 on freeway in warm weather or when starting out in cool weather, but can drive it to zero with the throttle.

 

[AH64ID]

Odd that those pressures aren’t enough as the CP3 in our trucks can deliver full fuel even under a slight vacuum. I could suck my pressure down to 2-3 without any issues at power levels well above stick, but on a younger pump.

 

[MBuechle]

Odd that those pressures aren’t enough as the CP3 in our trucks can deliver full fuel even under a slight vacuum. I could suck my pressure down to 2-3 without any issues at power levels well above stick, but on a younger pump.

Well, I just went out and checked my factory filter heater for continuity and found it wide open. The contacts are kind of hard to get meter probes on but I'm pretty sure i would have seen something if it was good. That would explain a lot.

 

[gsbrockman]

Well, I just went out and checked my factory filter heater for continuity and found it wide open. The contacts are kind of hard to get meter probes on but I'm pretty sure i would have seen something if it was good. That would explain a lot.

Glad you spent some extra time looking at the heater(s) instead of going with a lift pump...then still have the same problem. The OEM lift pumps are very reliable indeed.

 

[MBuechle]

Welp, got what I thought was the filter heater, turns out to be a connector with a thermoswitch. The actual heating element appears to be integral to the filter housing and would probably be a new housing if it failed. After removing the old one, metered the heating element, .4 ohms so good, though that seems low, calculates to 490 watts at 14v input. No way the 16ga wire feeding it could flow enough current. Perhaps the impedance goes up when it gets warm. Any way, installed the new connector/thermostat block. Drove to work this morning, 15 F out, fuel pressure fell to 4 psi them recovered to 5-6, no CEL, no rail pressure drop. Still not convinced my pump is not week but for now the problem seams to be solved.