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

Originally Posted by THE BULL

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!

Originally Posted by BossJ

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.

Originally Posted by Optimiser

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.

Originally Posted by BossJ

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

Originally Posted by Optimiser

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.

Originally Posted by phunk

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.

Originally Posted by BossJ

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

Originally Posted by phunk

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.

Originally Posted by BossJ

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

Originally Posted by BossJ

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

Originally Posted by phunk

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.