Airtex lift pump failure

omaharacer · **Posted:** Thu Oct 09, 2014 3:46 pm

I installed an Airtex E7181M fuel pump/lift pump in August 2012 - used "factory wiring" and added the positive/negative wires to the fuel pump.
I've since put around 30k miles on it and it just failed completely. The "pass-through" design doesn't work at all, completely blocked the fuel to the filter head. The primer pump barely pulls any fuel through since it's sucking more air through the quick-connect fittings from the high vacuum now.
I managed to limp it home after hitting the primer 60 times to get it to start, then it died about 10 seconds later. Imagine that 20 times, on the side of the road. Thankfully I was only about 3 miles from my house when that happened.
Prior to pulling the tank I had checked B+ signal, 12volts to the line going to the pump under the seat (P.I.T.A to remove... again) and it was fine. The fuel filter had been changed 2 times in this period, but I put a new one on anyways. Still major vacuum through the fuel lines. Something is restricting fuel flow.
Today, I dropped the tank and pulled out the pump, attached 12volt lead/ground directly to the pump. Nothing happened, pump completely failed.
Has anyone else had problems with their Airtex fuel pump, or did you install a different model? I seem to find the manufacturers that skipped out on quality control tests. (i.e. Crown water pump)

tjkj2002 · **Posted:** Thu Oct 09, 2014 4:53 pm

Very surprised you made it that long with a airtex,they usually fail in a few week or months.One of the worst brands you can buy.

gmctd · **Posted:** Thu Oct 09, 2014 9:10 pm

Be cautious of those blowing smoke as if knowing whereof they post............

AIRTEX pumps are made by CARTER, also blamed by DODGE engineers for millions of dollars of warranty failures in the big RAM Diesels.

Altho CARTER lift pumps have encountered higher failure rates due to oem refusal to follow installation instruction, could also be you do have a factory defective unit - full disassembly of the pump motor would tell the true tale, beginning with ease of rotation of rotor prior to motor dissasembly.

However, OWNERS MANUAL of vehicles with in-tank pumps are very specific in precautionary instruction:

Do NOT make a habit of running the fuel level down to the red\orange area on the fuel gage - this fully exposes the pump -with no surrounding fuel to keep the rotor, brushes, and bearings cool, greatly increased wear will be resulted during the interval when fuel level drops below top of pump to the point of raising the fuel level during refill - this is further exacerbated when adding only a few dollars worth of fuel, rather than a full fillup, due to economic situation.

Dirty fuel is also culprit in early pump failure.

The KJ CRD OpMan does not offer this precautionary warning, not having an oem-installed in-tank lift pump...............

omaharacer · **Posted:** Thu Oct 09, 2014 9:15 pm

The entire time the pump was installed it had more than 1/4 tank of fuel. If I can disassemble the pump without destroying it I will.

gmctd · **Posted:** Thu Oct 09, 2014 9:40 pm

While removing the pump from the fuel sender pickup module, note any sandy grit in the sump filter screen - then look into the inlet end, where you should see the rotor commutator - using an ice pick, awl, or other small-diameter probe, try to rotate the rotor, noting any resistance to rotation - it should turn freely with no pumped fuel head.

I have found scarred commutators, off-set worn brushes, burned bearings\surround preventing motor start-up - indicative of low-fuel operation, also with dirty fuel as additional possibility for scarred commutators\worn brushes

The one factory defect I have encountered was on my new-to-me pre-owned '01 24-valve RAM: difficult to start, hesitating, etc - disassembled the engine-mounted CARTER lift pump to find the bypass-type regulator consisted of a ball-bearing and a calibrated coil spring with reduced diameter coil on each end - spring holds the bearing on a steel orifice-type seat -fuel pressure overcomes spring pressure, regulating system pressure by bypassing excess fuel thru the orifice, back to the inlet side

Failure: ball bearing passed into the spring coils, such that fuel would flow but no pressure achieved - result: hard start, etc, but because full flow was available, the VP44 was not harmed - new CARTER lift pump installed back near the tank, as per instructions, and all is well at constant 14psi to the Injection Pump, since rework in 2010.

Also, very good point vis a vis the flow-thru function being very dependent on sealing method used on the fuel-line piping

omaharacer · **Posted:** Fri Oct 17, 2014 1:35 am

Follow-up.
I ordered a new Airtex E7181M fuel pump. The design has changed - pump, housing, filter media, pump, connections, float/float arm. Nothing could be swapped over. It appears that the original Airtex fuel pump was pulling too many amps and the wiring where I had spliced a wires for length 2" from the pigtail to the pump got very hot and came apart/melted, hence no 12 volts+ to pump. I installed the new pump and fixed the wire. New pump works as it should. Old pump also "works", but is being thrown out since it is likely failing. Float arm had to be slightly bent to be at same height at lowest point as old pump to ensure "empty" on gauge was the same.
I re-used the quick-connect plastic fuel lines, although I would rather have replaced them completely and used hose clamps to prevent any air from entering in the future. The filter pump/sock is actually filtration media instead of plastic perforated holes in the bottom of the old housing. There is also another filter media, difficult to see, under the black plastic cover for the pump/fuel return.

All 10 photos - https://drive.google.com/folderview?id= ... sp=sharing

gmctd · **Posted:** Fri Oct 17, 2014 1:05 pm

Now you see why the wire connections are crimped, rather than merely twisted together - the pump motor draws ~5a under full pumping load, seemingly insignificant when compared to the starter motor @ 100a, but never-the-less requiring fully-conductive connections - can twist and solder, but never with acid-core solder, with resultant blue oxidation, or corrosion, as it is known with (dis)respect to copper materials -could be you're getting fuel with excessive water content, exascerbating the corrosion.

Could be tested by crimping the connections, clamping a 20psi pressure gage into a rubber fuel line clamped on the output port, placing the assy in a gallon of Diesel fuel, and power up - pressure should be ~15psi, current draw should be ~5a @ +12.6v

I would estimate that fuel pump to be functional and still usable - keep it for MURPHY'S law situations..........................

Airtex lift pump failure

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