AEM E85 Fuel Pump - Tube keeps falling off...
 

So title says it all...

Just put in a AEM E85 fuel pump in my 2016 370z Nismo - and the tube has fallen off the pump twice already, leaving me stranded - and towed right back to performance shop.

Just talked to Seb at SpecialtyZ and he's had similar issues, is there any FIXABLE solution to this pump?

We've tried 2 clamps and now 2 clamps and a heat shrink e85 tube (praying this one works) ...

Anyone else had this issue? Does AEM even know that this is an issue with their new revision?

This tube?

I ve had good luck with this tube and clamp set up.

Yeah is that a heat shrink e85?

What size hose are you using?

This is an E85 compatible tube with special clamps. You have to use side cutter pliers to deform or crimp the clamp around the nipple. It is hell for tight when done right.

This tube and clamp came with the Deutch Works pump kit I bought, see the image below.

The stuff in the DW200 370Z kit all fit my 370 perfectly.

The AEM pump kit i purchased originally, did not really fit my fuel pump module. The wiring for the pump is huge, and the car harness will run hot because the AEM pump pulls more amperage. The hoses are not real great either. So, I sent the AEM kit back and run the smaller DW pump with great results. Charles (CJM) really helped me with my fuel pump upgrade.

Thank you. I’ll look into this if I get stranded again.

So a tuner of mine said, if I just turn the car on snd let it run for awhile - that would be a good test for the tube staying on,

Is this a good idea?

Because frankly, I just don’t trust my car right now and if I get my pregnant wife stuck one more time, she may kill me :) - JK she loves the car but hates what it’s been doing.

I mean if the hose blows off the fuel pump the car will die even if parked.

So, that might be a good initial test.

Thanks. Been running it for about 4 hours today, off and on... hasn't blown off yet...

Last 2 times it blew off was about the 4 hour mark - once at stopped at a light, idling and the other time driving down the road.

Does the pump not have a hose barb on it? Once the clamp is tightened, the inside diameter of the hose should be mechanically reduced enough that it could not fit over the hose barb and come off.

Nope - the new version of the AEM e85 pump has no barb on it... -_-

Seb has had issues with it as well, he's had to double clamp...

oh geez, what a dud. I wouldnt use it at all. Maybe in a 350z since that pump housing doesnt need a barb the way it supports the pump from the bottom and holds it up into a rubber grommet. But the 370z has to have a hose connected, and with no barb, that is useless IMHO.

Yeah if it does it again, I'm gonna trash it, and talk to AEM about why they changed it.

But is there anything else out there? The DW pump?

On another note.
How big is the pump?
Do you have a FP gague?
Did you drill the pump assembly?
Are you still returnless or is it a return style?

Usually E85 pumps are an upgrade and are higher flow, this is why the assembly needs to be drilled to relief some of this extra pressure it creates since the factory fuel pressure regulator located in the pump cannot control pressure since the added flow turns into added pressure since the injector duty cycle is low at idle. This is where a pressure gauge comes in handy, if this is the case you should see an increase in pressure at idle - the fix for this is to drill the relief a bit more.

A heavier duty hose and clamp will stop the tube in place but if you've not done what I posted in the top you'll have fueling issues in the future.
This is the downfall of the returnless system - any increase of flow will turn into pressure if not regulated.

Good luck!

So bare with me, I'm not a vet on here or smart when it comes to cars, like most of you on here.

I take my care to a performance shop in town, who's been amazing, up till this issue (and it may not be their fault necessarily).

They recommended (as well did Seb) the aem50-1200 fuel pump.

How big is the pump? aem50-1200
Do you have a FP gague? No - but this may be my next purchase
Did you drill the pump assembly? No idea - I don't think it needed it? (Again, I'm not a car guy to this extent)
Are you still returnless or is it a return style? I'm guessing it's the same as stock. Nothing changed but the pump.

Just know, I'm not the smartest with cars, but I do not make any changes to the engine without first talking to Seb about it.

Thanks for your help and questions guys.

Yes there are several other pump options from DW, Walbro, Aeromotive, and AEM probably even has other pumps with a hose barb.

This is AEM 340L E85 Pump (AEM 50-1200) I'm using now with (no barb) just hose clamp with no issues after over a year. My regulator has been previously drilled wider though as per the Stillen SC instructions for a larger than stock fuel pump.

So maybe the regulator not being drilled wider is the issue?

I believe it should be for a larger than stock fuel pump.


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Drilling the regulator and venturi jet is a separate issue IMHO. While not drilling them will cause a fuel pressure spike at idle; 20-25psi in a line that small is relatively low pressure and should not be pushing the hose off a barb. That type of pressure deviation is a big deal in the way that it effects tuning, but it should be insignificant to the physical construction of the parts. If that is all it takes, I would still be looking for a different pump.

The pump kit in that photo seems ridiculous to me. I can see for maybe a low pressure scavenge system it would be fine.. but still, why even produce a fuel pump case without barbs? Seems like a proprietary fitment that should only be used with a bushing in a case, and inappropriate for use with a hose and clamp.

So - so far the only way I've 'fixed' this and hopefully it stays fixed is with a - heat shrink e85 tube... and double clamp... I know a few others have used this pump and it's fine, but that's my only solution.

My question is, I need to get the regulator and venturi jet drilled now? Seb didn't mention anything about this...

Here's a maybe separate issue? I'm randomly getting RPM drops after driving for a bit and stopping. I'm cleaning my MAFs and throttle bodies tomorrow - so far that seems to be the more likely culprit, could it be the new fuel pump?

Seb said I didn't need a new tune and he looked at my tune after fuel pump installation and said it was fine - other than the rpm drop (he's looking into it).

Thanks guys

Well I guess I've been lucky then. ;)

The drilling was probably done at the same time the fuel pump was installed. Especially if you had it installed at SpecialtyZ, they would be well aware that you need to do that any time you upgrade the fuel pump in the Z. You may as well keep using the pump since you already have it and its holding together for now. But anyone reading this thread should be able to tell they should avoid it and get something else if they didnt already buy one.

So I should of been more clear.

I'm in FL - so I just chat to Seb on the phone every great while. My shop in town, did not drill anything.

I take it, that NEEDS to be done - What do I tell them exactly to do? I'm going to Ztuner in Bradenton tonight, to get it dyno'd and looked at...

I just got my MAFs and TBs cleaned out as well.




Thank you

If the pump is flowing as advertised, it would need to be done. A fuel pressure gauge is the only way to confirm its necessary, or that drilling has been sufficiently performed.

https://cj-motorsports.com/p/tech

find the 370z fuel pump tech PDF. Have them read section 8 and 9 on repeat until it makes sense.

Thank you.

So I went from the walbro 255 to these AEM pumps with the radium fuel hanger kit and so far no issues for me. Been about a month now. I was nervous of the lack of a barb but couldn’t stand the noise of the walbro and even after drilling the jet out in steps the fuel psi was still a bit high at idle and seemed to have some surging offidle. Now I’ve been very happy with these pumps and kit. Very quiet and I am able to set my fuel psi regardless of pump chosen with the adjustable regulator. Cars been driving good and just got back to town and will start doing e85 logs. I have heard the hose blow off in other places too like on donut media so I do think it’s stupid for AEM not to have one but so far I’ve been good, if it does fail Blow off I’ll be going with DW.

Curious if you've actually heard a walbro and it's too loud or just going off of what others say? I have a 525 and there was a barely audible hum with all of the interior pieces off and the top hat exposed, with all the interior back in I literally can't hear the pump at all. All my fuel "noise" comes from the fuel pressure regulator in the engine bay.

Yes as I said I came from the walbro 255 and it was stupid loud (in my opinion). The walbro 255 is notoriously loud and is actually louder than their higher volume pumps. Google search it and you’ll find videos of it louder than an American muscle v8 exhaust and then switched to the DW and being whisper quiet. The walbro 255 is a vane pump most others (I believe including walbro higher volume) are turbine pumps.

I overlooked the part of you having the walbro 255, my bad. I was just pleasantly surprised with the 525 as I had expected it to be fairly loud.

Blog Post Radium's Ultimate Fuel Pump Test

My DW is very quiet, and low amp draw, so these are reasons I wanted one.

It wont support big power, but it will make 400hp NA on E85.

Keep us updated, usually when taking things to others and these issues happen then I would ask the OP to take it back to that person and have them at it. Usually as well those that end up taking the work know how to on these installs (hopefully) and are able to get it fixed.

The reason why it's popping off after the right measures are taken is excess pressure from the pump.
With a fuel pressure gauge you'll be able to confirm this theory and can point you in the right direction as to what next.

My twin 450's are not even noticeable. You can barely here my one pump running at startup.

Right. I believe the 255 is the only one that uses the vane system.

If that is like an old Bosch 044 then that thing was noisy as hell.

Chatted with seb - after putting on dyno - I’m 30hp off where I should be. Getting it drilled tomorrow and fuel gauge installed and then Seb is retuning it.

I’ll keep you posted.

Hey, I recently installed a 340lph aem fuel pump as well. I had issues for a while with the fuel line coming off and now I’m having issues as well with the wiring. What did you use to connect the wires? And what did you use for the line?