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Anyone have this issue with aero motive pumps!?!?!

2.6K views 23 replies 9 participants last post by  Cclaro  
#1 ·
ive been chasing fuel pressure drops for months now with aero motive pumps. ive tried 5 different 340lph, a smaller 200lph, different inlet styles, improved wiring, heat wrapped all lines in the engine bay, but every single aero motive pump ive had has eventually started to become noisy and drop pressure under WOT. im talking from 43 psi to the mid teens. threw in a cheap 255 and problems immediately went away. pressure held steady as a rock versus the aeromotive pumps that even out of the box would be dropping 2-3 psi under no load just revving it in my driveway. are these things just junk? an aero motive rep and I tackled this issue for several weeks and even he couldn't figure out what was going on. wiring checked out, voltage was good, flow tests when the pumps were new came out fine, feed and return are sized fine for my power level (around 450 crank, running -6 an the entire way), tried two different regulators (Holley and aero motive), but after a couple weeks these pumps just can't hold pressure to save their lives. some came completely junk out of the box and I had to send them straight back. just gonna switch to walbro and hope that solves my issues permanently but I just find it really odd how a no name 255 pump almost seems to vastly out perform these pumps (no loss of fuel pressure whatsoever under wot conditions). Anyone else have this issue with the 340 series pumps?
 
#4 ·
Lots of issues with them years ago, I moved to Bosch pumps, but you need to be careful with them to make sure they are genuine and not knockoffs. I guess you have to that with pretty much everything these days
 
#6 ·
Yea, the Aeromotive 340's were crap.

These are awesome, pumps, and a fuel hat that's 10x better than stock **** or "retrofitted" stock style stuff.


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#9 ·
I have had similar problems with their A-1000 and Eliminator pump. Sent my Eliminator pump in to them in the fall as the PSI was dropping under boost by about 10psi. they rebuilt it and said it was a little down on flow.....$300 later.
 
#11 ·
#16 ·
Ive been using Kemso 340lph pumps for quite a while and other than having 1 DOA, I have had really good luck with them. Im using a pair of them in my 95. One is triggered at 3psi to kick on. They have worked flawlessly for me and for friends. @Cclaro have you tried different sellers?
 
#17 ·
Ive only used real walbros and only had one problem in the better part of 20 years using them. Ive used 255lph all the way up to the 450lph pumps and theyve always been reliable. So much so that even on the race cars Ive had I choose to do dual and triple pump setups with a hobbs switch over one big pump.
 
#18 ·
I agree that Genuine Walbro is a great product and using multiple pumps with a hobs switch is the best way to do a multi pump street / strip vehicle as running both pumps all the time a) puts unnecessary wear on the second pump and b) heats up the fuel by constantly sending way more fuel than needed it through the pumps / system when fuel consumption is low. When running this config, It is also a good idea to swap the wiring of primary and secondary pumps so they get similar use - not that I did that much.
 
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#23 ·
i think we talked about this before when you were trying to diagnose it previously. Do you have the sender in the regulator? Have you thought about adding a fuel pulse damper? I had all kinds of issues with inconsistent fuel pressure readings until I added one. This is what I have and it completely changed my fuel pressure readings. Fuel Pulse Damper, Direct Mount Kits. I can already tell you people are going to say "My fuel pressure is fine and I dont have one of those" How much money have you spent changing pump after pump after pump. Why not install one and see if it helps because it absolutely fixed my issues. Fuel pressure dampers are installed from the factory on most cars after 96.
 
#24 ·
i think we talked about this before when you were trying to diagnose it previously. Do you have the sender in the regulator? Have you thought about adding a fuel pulse damper? I had all kinds of issues with inconsistent fuel pressure readings until I added one. This is what I have and it completely changed my fuel pressure readings. Fuel Pulse Damper, Direct Mount Kits. I can already tell you people are going to say "My fuel pressure is fine and I dont have one of those" How much money have you spent changing pump after pump after pump. Why not install one and see if it helps because it absolutely fixed my issues. Fuel pressure dampers are installed from the factory on most cars after 96.
the sensor is mounted on a fitting right on the rail. Looks like I’ll have to give that damper a try.