Aftermarket fuel pump failure?

[Matthew Jeschke]

@exp500 excellent suggestion!

Looked up P0230 in FSM. It's basically what I thought it would be, the control circuit for the relay (not power side). If the relay fails the PCM would notice no current flowing through the circuit and trip the code.

I completely tore down this pump. WOW is it a piece of art. VERY well built. Took the armature out of the pump motor. Trying to assess the windings. Find something odd but not sure if it's an issue. Most of the windings are 0.6 Ohms but a couple are just over 1 Ohm.

 

[Matthew Jeschke]

This maybe the fault. First anomaly I found. The commutator is very soft which is obviously for design reasons. However, depending on where I touch the commutators and or how hard I press resistance changes by as much as 300%

New video by Matthew Jeschke

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I don't think that's a design feature? Least I couldn't see why it would be unless (1) it's a fail safe although higher resistance is higher heat, which I presume is bad in fuel tank. Or (2) it's a way to slowly fail the pump as brushes wear, pump pressure decreases signaling time to replace pump. Otherwise my DC motor research showed this as being a condition of loose windings where the commutator connects to the winding / inductor wires.

I fiddled with another DC motor I have apart and it didn't behave that way at all when testing commentator and windings.

To credit of pump when I installed brushes (they are spring loaded of course) the commutator resistance was consistent across the motor leads (behaved as expected).

 

[Matthew Jeschke]

Don't think it was the fuel pump. Installed new pump and get same pressure reading 52 PSI KOEO.

Pressure regulator squeals?

UPDATE the squeal is a function of the regulator. Maybe a sign it's going out? I swapped another regulator in I had in my garage. No more squealing. FYI ~ Cannot return defects to RockAuto like I can to my local parts store. I can only exchange if passed refund period.

The pressure regulator also makes a odd squeal if I jumper the pump on with engine off. I have two other pressure regulators. I may swap one of the others in to see if the squeal goes away.

Anybody had troubles with Standard Motor Products? The pressure regulator in the vehicle is one of theirs...

More Information for STANDARD MOTOR PRODUCTS PR217

I will likely return it / swap it as it's loosing pressure.

Pump harness was loose: Removing the old pump I noticed the pump harness wasn't locked on... It slid off which may have been the problem.

Few other observations, the aftermarket pump draws 11 AMPS at 12.4 Volts (AGM battery).

Circuit is pulling 11 amps at 12.4V continuous relay rated for 10A @ 12.0V?

The relay is a factory Omrom 8567. In open air (hood open engine cool) the relay heats up on it's own to over 120F within a minute or two. I'm reading the data sheet for those relays. It's a little cryptic but appears the lowest rating for continuous current is 10 Amps. The pump maybe pushing the relay a bit much!

Datasheet: https://omronfs.omron.com/en_US/ecb/products/pdf/en-g8v.pdf

Going to buy a 30 Amp Micro 280 (mini relay)... I think I'll leave an omron in the port though to see if I can provoke the failure again then switch the relay with the 30 AMP one.

https://www.oreillyauto.com/detail/c/bosch/bosch-30-amp-4-terminal-relay/bos0/0986ah0115?q=0986AH0115&pos=0

Junction block losses: I had suspected the junction block wouldn't handle the load. However, it seems to be a non issue... On input side it's dropping 0.3V that's all the way to the load side on the relay.

 

[Matthew Jeschke]

It broke down again

It seems as though the power line to the fuel pump is cooking the inside connection on the fuse block. I think I have to break the threaded part of the junction block to separate it and verify?

However, when pulling the relay the block smells burn. I let it cool down and truck worked fine after that.

I'm kind of wanting to just bypass the junction block and do an external relay and fuse now for the fuel pump. However, I am not sure which connector is B7 for the signal from PCM to relay?

If I was to put a larger connector inside the block... I'm not sure how to separate the fuse block without mucking up the flared end of the threads where the connectors screw in underneath....

 

[Roilux]

Spent an hour idling truck in garage to try and recreate failure. Not sure how accurate my fuel pressure gauge is... However seems when I put in my new regulator in I verified 57 PSI KOEO. I'm getting 52 KOEO right now.

There's also a weird noise in the fuel line when I hotwire the pump with my power probe. It's resonating through the whole fuel rail.

When I start the truck I don't hear that noise in the line set. It's like a squeaking noise. It's so loud you can hear it w/o the stethoscope.

Would you be able to hear that noise or pressure regulator squeal from the driver's seat? I had an intermittent noise I've not been able to identify. After the second occurrence the fuel pump was replaced the following day when fuel line pressure dropped to 40psi. (L59 engine)

 

[Matthew Jeschke]

Yeah I can hear it from inside (although it's not terribly loud). I honestly thought it was a slipping serpentine belt. Turns out it's most definitely a noise with the pressure regulator. I tried two regulators, both exhibit the same behavior.

Diving deeper it maybe linked to my engine's PID loops in the tune. The engine idles PERFECTLY with the spark controller. Then every so often it stumbles, runs every so slightly rough and the PCM picks back up again. I think that's when the regulator makes it's little squealing noise.

 

[Roilux]

Thank you!

 

[exp500]

Yeah I can hear it from inside (although it's not terribly loud). I honestly thought it was a slipping serpentine belt. Turns out it's most definitely a noise with the pressure regulator. I tried two regulators, both exhibit the same behavior.

Diving deeper it maybe linked to my engine's PID loops in the tune. The engine idles PERFECTLY with the spark controller. Then every so often it stumbles, runs every so slightly rough and the PCM picks back up again. I think that's when the regulator makes it's little squealing noise.

Have you checked for a loose/corroded PCM connector or similar ground? Intermittant failures are tough to trace when everytime you touch it it works. The only positive is your possibles list is getting shorter.

 

[Matthew Jeschke]

I should have updated the post... Thanks for tip...

Looking like it was a bad junction / fuse block. I replaced it moved pump supply relay to outside of junction block. Haven't had problem since. Also it got rid of heating in junction block as I think the current draw from aftermarket pump wrecked the original fuse block

 

[Matthew Jeschke]

OMG, forget this pump. I pulled it out this evening. I'm getting so fast at dropping the tank I might as well join a nascar pit team. Three hours to diagnose, drop, install new pump and put tank back with janky stands and no room. I digress...

Was driving and it did the EXACT same thing again. Started to go lean and eventually truck stalled. I swapped battery (have been carrying a spare battery to be on safe side after new efan mod).

Truck would crank but not start. I kept trouble shooting. Threw my hands in the air and then it started up. Drove about a mile, stalled again. Coasted off road. Took entire junction block apart, started probing wires... Couldn't find fault. Started up again and drove home. Stalled in driveway. Fiddled some more again, and it started up.

I hooked up my fuel pressure gauge and there was LOTS of air in the purge hose. Truck would start but fuel pressure was all over the map (fluctuating from 25 to 45 PSI). I thought dang, the hose came loose in the sending unit. Dropped tank and hose was secured like a rock yet.

I brought a power supply out of my lab. Fed 14 volts to the pump and timed it filling a one gallon jug. Took 60 seconds. Pump sounded healthy but there was a weird sucking noise.

I next did same thing but filled a 6 gallon gas can. Took more time per gallon completing six gallons in 8:30 seconds. While filling the 6 gallon jug I put an endoscope into the fuel basket. IT WAS DRY! That pump was pumping SO fast it was SUCKING the basket DRY!

I wondered maybe it would do that w/o the return hooked up. Because the return line would fill the basket back up. Surely this pump works as I've seen other people install it, on YouTube and another friend has it but his system is returnees turbo truck. However, they used the factory sending unit basket.

I put in the factory pump again and tested it in the basket. It flowed slower than a snails pace compared to the aftermarket pump. However, it didn't suck the basket dry. Not even with the tank being nearly empty.

I think that maybe the culprit. I grew a new habit this year, that is allowing my tank to go below 3/4 full. If I got below 1/2 full it started to exhibit issues of the sending unit basket going dry. I think for the first thousand miles of having the pump or so I never let the tank go too low.

Additionally, the fuel pressure regulator squeal went away. That squeal must have been air getting into the fuel line.