Turbojack

Learned something here. I am using the areomotive pump also but with 2 carbs instead of EFI. I can see where air temp is high, filter not flowing enought that it could let engine lean out.

this is link on filter info

I wonder if fuel filter on inlet side caused cavitation on pump & caused the epoxy to let loose. So in reality 2 problems. Filter not big enough on inlet & no filter on outlet side.

Nordicflame

I've heard a rumor !!! (from the horses mouth BTW)
Until last year the afore mentioned pump had an issue with the epoxy breaking loose and the magnets falling off. This obviously caused pump failure but it appears the fallout from this is even worse.
Aeromotive has re-engineered the pump and now the magnets are mechanically fastened resolving the problem.

Your pressure may have dropped do to losing one of the magnets and also leaned a cylinder because of a momentary clogged injector. We may be seeing what could be a viable reason for your predicament but who knows.
Later

blown formula

Ok, I called Aeromotive & this is what I learned.
The Merc fuel filter/water seperator may be restrictive to the pump in that the micron size of the filter may not allow enough flow to prevent the pump from actually cavitating (boiling) the fuel thru the pump. They recommended their filter #12304 on the inlet side.
In regard to the epoxy tyhat was release by a Aeromotive pump. There was research done after a failure was reported (only in the Marine environment though). The cause was discovered to be high alcohol content in the fuel was, when left idle for extended periods of time (as boats do), the alcohol was desolving the epoxy holding the motor magnets to the pump. Pumps manufactured AFTER May 2002 are mechanically secured to the magnets. No more problem. Pumps may be returned to Aeromotive (with an RA#) for testing and flow checking.
A contributing factor here is the filter water seperator on the inlet side, Aeromotive suggests it be put on the OUTLET side so the pump pushes thru it, not pulling thru it.

See next post to continue:

blown formula

The fuel pump is recommended to be fed by gravity from the bottom of the tank, not the top. When fed from the top, the "prime" can be lost and the pump can start dry, possibly causing damage to the pump if it runs too long dry. A check valve can be installed to prevent this.

Recomended filters: inlet side #12304
outlet side: #12301

Also, under boost conditions if enough pressure is created in a cylinder, this can cause a "cross-fire" situation. If an adjacent cylinder crossfired to another, then total timing could be changed as much as 30-40 degrees.

They also recommend checking the injectors in my case & also flowing them......

Bottom line: use two filters
flow injectors
plug wires to prevent crossfire
no alcohol in fuel (if possible)
option: fuel check valve to pump inlet

push fuel thru the seperator

blown formula

Is that enough to absorb in one day......a complete redesign of our fuel system for EFI application. Carb'd systems can get by with less due the the fact of the lower pressures involved.

This makes me tired!!!

Turbojack

Would you put the outlet filter before the regulator or after it? Before regulator than you would not have any addtional pressure drop to engine due to restrictions. After, the filter would not have as much fuel going thru filter (bypassing back) & pressure would be lower, but gauge would need to be on output of filter side to set regulator correctly.

blown formula

The filter should be on the pump side of the regulator, so only double filtered fuel was dumped into the tank. No chance of epoxy making the trip!! Also, as you said....pressure would be true pressure. I have my electrical senders on the regulator and mechanical gauge mounted to the EFI fuel rail directly at the input fitting. Try to match pressures but rely only on the mechanical for true readings. The gauge is only a "warning" indicator!! not true pressure.

Nordicflame

Hey Blown,
See you got the same story as I did. Did he tell you that they would rebuild our older pumps with the new motors for a fair price (I think it was $180). Apparently these put out quite a bit more also. I’m going to do it just for insurance purposes. The longer my project takes, the more it cost, however that may prove favorable in the long run.
You know, you may get a lot of different opinions on this but the best foolproof fuel delivery system that I have encountered is one I learned of after many, many weeks of fighting fuel delivery when I converted to a Holley/HiRel aftermarket MPI setup from a carb setup. You may not have some of the parts but they would be easy to get.
You feed thru the stock separator (or upgrade, it doesn’t really matter even though you think it would) to the mechanical pump that is mounted with the seawater pump. (According to Dennis Moore, author of Big Block Chevy Marine, these pumps put out 120 gph at cam shaft speed; double this for running off the crank via a belt) Bottom line is it will support a lot of hp. You run the line off of the pump to a much larger Racor filter/separator, which is about 8” tall and 4” in diameter and has 3 input and 2 out lets. You extend the fuel pickup inside the filter by about three inches with a 3/8-pipe nipple. The outlet goes direct to the high-pressure pump that is mounted below the Racor level and then routed back up to the fuel rail. (It will also always be primed this way) After it leaves the regulator it immediately runs through a fuel cooler and returns directly to the Racor filter. You will always have an ample suplly of cool fuel.
I have run this setup for four years and it supports my 540ci/575hp motor with a small Volvo/Holley pump that I believe is only rated at 60gph at 43.5psi. HiRel’s fix for what was thought to be inefficient pumps was to run two of them in parallel for over 400 hp; wrong! It has never vapor locked or acted strange in anyway and most importantly the fuel pressure has never dropped below 43.5psi with a single small pump. I will be using the new Aeromotive with the ProCharger however; don’t want to push it.
I have a friend running well over 600hp with his 540 and this setup and also a twin Vortec, 1100hp setup, running the same except for larger 1/2” fuel lines through out and larger high pressure pumps.
Like I said, you’ll get a lot of differing opinions on different methods. The only thing I can tell you is that this is proven and tested as many others are also I’m sure.
Hope this helps,
Dave

guillermof

That is why I used Weldon fuel pumps on my new motor. A little or allot more expensive but first quality aircraft pumps never fail. I always say you get what you pay for. By the way I blew two AZ speed/sun country blower motor because of bad workmanship

cobra marty

NordicHeat, You have found what I also run. The electric pumps don't susk well and because most boats have low fuel tankss and can't gravity feed the electric pumps. I run run like you said thru the seapump driven mechanical to the filter-aeromotive pump -filter and then to a 'T' and feed the back and to the front of the fuel rail ( it is only 1/4-3/8") then to the regulator and dump back to a t infront of the mechanical pump and not the water-fuel separator as you do. Mech pumps suck well and electric build great head pressure.