I also did a fuel pump test. The rattling you'll hear is the car almost dying.

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Are you sure you don't have a kinked line or issue with the pump intake getting blocked? I have the exact same setup you are running outside the fuel injector size. Mine works just fine at WOT.

I will say that the other day after coming around that bend from 94 West to Southfield North just before the Outer Drive exit, I gave it some gas around the bend and then when I let off on decel, the car suddenly died (it was not under load when it died). Key cycled it while coasting and returned to normal. VIDA shows it lost fuel pressure. Not sure what that was all about, but my pressure at idle is solid (verified in VIDA and with a mech gauge on the fuel rail). Might have been a fluke or something yet to rear its ugly head, but I have had zero issues under load. Ping me during the day and maybe we can meet up near the office one day.

 

Are you sure you don't have a kinked line or issue with the pump intake getting blocked? I have the exact same setup you are running outside the fuel injector size. Mine works just fine at WOT.

I will say that the other day after coming around that bend from 94 West to Southfield North just before the Outer Drive exit, I gave it some gas around the bend and then when I let off on decel, the car suddenly died (it was not under load when it died). Key cycled it while coasting and returned to normal. VIDA shows it lost fuel pressure. Not sure what that was all about, but my pressure at idle is solid (verified in VIDA and with a mech gauge on the fuel rail). Might have been a fluke or something yet to rear its ugly head, but I have had zero issues under load. Ping me during the day and maybe we can meet up near the office one day.

If I had a kinked line or a clog, wouldn't the fuel pressure just not reach the requested pressure and not drop like it is? I have checked for kinks in the line I installed on the pump, but there's no apparent sharp kinking. ?

I definitely will. I still have to give you the tool set back now that I've confirmed everything is running right haha!

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That is pretty wacky. Looks like the pump is flowing for a bit and then gets starved.

 

UPDATE:

RMA'd my pump and got the new one installed the other day. It WAS my pump! I guess the pump was killed off when I had the connectors switched and had the main pump at 100% for a while.

Enjoy this smooth fuel pressure plot. The car pulls so damn hard now, I can finally get a taste of whats coming! Its at 15psi of boost now, so cant wait till its tuned for more!

 

Nice to hear that!

 

Update: the issue came back. Going to remove the entire pump assembly and transfer line out and inspect everything. I have no idea why it would just come back after a couple weeks.

 

Weird... on another note, you heading to the dream cruise at all? I might take my boys there one day with the R.

 

I just pulled the bucket out and it drained itself and doesn't feel like there's any resistance when moving it around. I think something is broken on the bottom.

Also probably, last year was hectic and the traffic was horrid. We might meet up at Svenska Cafe for a Saturday/Sunday meet.

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I hope you didn't break that little plastic fitting that is integrated into the housing. I did and had to get a new assembly. But I still have that broken one if you need any parts off it.

Good work solving the issue, I had a similar issue with my factory pump and replaced it with an Aeromotive 340. Now my fuel gauge doesn't work but that's a different can of worms ...

 

The fitting that the pump line does on to? Yeah its got a small hairline crack at the bottom, but I highly doubt that would cause any of this because the line goes all the way onto the fitting, there's no room for the fuel to escape out.

Also, this isnt normal right? maybe my transfer pump is dead or dying? Maybe thats why my startup RPM jumps up and down then smooths out? Shouldnt both sides of the tank have an even fuel level?

driver side access

passenger side access

This is why my startup has always looked like

My last resort is to buy a new pump bucket assembly and replace the main pump. But im short on funds right now and im trying to do this without spending anything.

 

You should change the whole assembly if you can swing it. Might be the hose, might be the transfer pump. I think I have a spare new one but that is up to you if you get me a part number to confirm and send me $20 I send it to you. Also suck that dirt out of your tank.

 

That would be awesome, I'll text you when I got there number. And yes, I need to empty the tank somewhere and clean it out.

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Update:

I've replaced every fuel system component and the primary O2 sensor (excluding the 1000cc injectors and fuel lines) in the past 2 weeks, and im still having the same exact issue. I've run out of ideas. Neal has been an amazing help along the way and has been helping me diagnose the issue for the past 4 months. Still, we haven't found anything faulty.

I still can't do a pull without losing fuel pressure.

For those interested here are two logs (the pink and orange line in the 3rd row should match each other):

How it should run:

How its running:

 

Ugh that stinks dude. "Every fuel system component" - I assume that includes the FPR? And I assume it isn't throwing any codes?

 

Nope, no codes. My VIDA laptop broke, so I dont have VIDA to test anything sadly

 

Im gonna lift the car up and check all the fuel lines to see if there are any kinks or leaks.

 

I know I asked this before, but are you sure the line connected to the pump inside the tank is not kinked? It sounds like a starvation issue. Did you loop that hose or is it straight?

 

It's looped.

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That's how I did mine too. And you verified there's nothing funky on the inlet side of the pump where the screen is?

 

Fuel Pump



So just saw this and its similar to my issue I had.

I had a bad fill but you couldn't see the debris. To bring a long story short, I changed fuel pumps and filter, pressure regulator and all other things. My issue was happening when on 50% and bove and it was sying as the pressure dropped then it was ok for a while (few seconds)

The final way I resolved my issue was to remove the filter on the bottom of the fuel pump and relied on the fuel filter on the bottom of the car to filter the fuel.

I ran this for 3 months with multiple fills then replaced the fuel pump.

No issues since.

You have nothing to lose removing the screen

 

FWIW My screen cracked when I installed the pump... due to the amount of force I used to push it in the basket despite having filed down the ID of the basket a fair amount. Not sure if that's helping at all, but worth a mention.

 

Not sure if you already tried this try swapping your PEM with someone for testing.

 

There is a pressure relief valve inside the assembly which opens at 650 kPa. Maybe something is wrong with it and this is the culprit?

 

Tested it yesterday, I plugged the relief line to the old Volvo top hat, it didn't open nor did the POS2 fuel pressure or idle duty cycle change.

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Wehlp. its all good bois! The original leaning out problem was being caused a bad transfer pump in the original pump assembly. Changed that, but was faced by the same issue, however, this time it was because there was a very unnoticable leak at the flexible fuel line from the main pump to the top hat. That caused a loss in pressure and thus causing the pump to work overtime. Also caused fuel pressure to escape after turning the car off.

Thanks to everyone that helped and thanks a million to Neal for helping me out with this issue for 4 straight months. <3

Took the car out tonight and did some logging in 60F ambient temps and oh my god the car pulls so hard and the power never ends! Cant wait to switch to E85!

PROBLEM SOLVED!

 

Congrats on solving it! That line sucks! Mine snapped off when I pulled it a little too hard. Enjoy E85!