Electric or Mechanical Fuel Pump?

[FJ4013]

Rig: 1978 FJ40

Not sure if my fuel pump is the cause of some recent issues but please tell me what you think. Starting last week while shifting into 3rd gear the engine lost power momentarily then regained power. None of the gauges flat lined so power was fine.

Then today the engine died on me 7 times while heading home. Each time I had to wait about 10 minutes before the engine would fire back up. Finally got it home and I'm trying to figure out what is causing this issue. Just driving along and the engine completely dies. Again..the gauges do not flat line. The engine simply dies.

I think it's time to replace my fuel pump regardless and here is a picture of the current fuel pump installed by the PO. Can anyone tell me the advantaged of a mechanical vs an electric or vice versa? I'm looking to replace mine with an OEM fuel pump. Any insight is greatly appreciated.

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[reddingcruiser]

For starters you need to get the fuel pump a lot closer to the fuel tank. Electric pumps push great, but suck at sucking. The only problem with external electric fuel pumps is they are prone to heat failure, that's why the factory puts them in the fuel tank on modern cars and trucks. I would stick with an electric pump, but move it much closer to the tank.

 

[JohnnyC]

Lower the better on those pumps as well ... if your loosing ground it will stop pumping ... if your loosing power to the pump it will stop

Crud in the tank will block up the line or also fuel filter .... the metal thing attached to the pump is also a fuel filter... it's a poor excuse for a filter ... they get clogged quickly

Is that the only filter?

 

[FJ4013]

Any particular electric fuel pumps for a 1978 FJ40 anyone would recommend? Also has anyone actually installed their electric fuel pump inside their gas tank?

 

[B y r o n]

I'm not familiar with the '78 distributor but I had a similar issue with a '75 Camaro with HEI distributor. The module inside the distributor had an electrical trace that would separate when warm and kill the engine. After a few minutes it would cool and make contact again and the car would start and run fine until it heated up again and then it would die. A mechanic found the issue, replaced the module and no more problems.

What I'm trying to pass on is just don't start replacing items unless you know they're bad or you could be out lots of money and still have the problem.

 

[tls3601]

How about just running the OEM mechanical pump?! Still available, never have to sweat it shorting out either! I got mine from City Racer @Racer 65 here on mud. Roger is super.

 

[FJ4013]

I'm not familiar with the '78 distributor but I had a similar issue with a '75 Camaro with HEI distributor. The module inside the distributor had an electrical trace that would separate when warm and kill the engine. After a few minutes it would cool and make contact again and the car would start and run fine until it heated up again and then it would die. A mechanic found the issue, replaced the module and no more problems.

What I'm trying to pass on is just don't start replacing items unless you know they're bad or you could be out lots of money and still have the problem.

That is EXACTLY what is happening to me. I just rerouted the fuel lines to a lower position to see if perhaps vapor lock was the cause and after driving around for 30 minutes and the engine getting up to temp the engine cut off again. I pulled over and lifted the hood. Anytime I lift the hood to let the heat escape quicker and cool faster it starts up much sooner. So somewhere something in my engine with a sensor is shutting down based on heat build up. My engine is not running hot either which makes this even more perplexing.

 

[brian]

How about just running the OEM mechanical pump?! Still available, never have to sweat it shorting out either! I got mine from City Racer @Racer 65 here on mud. Roger is super.

and you can't hear it.

 

[FJ4013]

and you can't hear it.

I have a Weber carb and supposedly an electric fuel pump works best with it. Here is a write up on CruiserCorps regarding this. I am not a carb/fuel pump expert. If anyone has an opinion contrary to this tech tip then please share it. BTW...this same pump is for sale on Amazon for $50 less. Just an FYI if anyone is interested in buying one.

From CruiserCorps
FJ40, FJ45, FJ55, FJ60 Fuel Pump - Electric - Fuel Pump - Fuel

Fits FJ40, FJ45, FJ55, FJ60 1958-1987 - This Fuel Pump is a great addition when converting to a Weber Carburetor. The Weber requires more fuel flow to operate efficiently and this electric Fuel Pump pumps 10 more gph than the mechanical pump used with the single barrel and double barrel carburetors. This is highly recommended by our restoration experts.
- Compatible with all fuels and additives
- Self-priming pump with a simple two wire design
- 2-3.5 psi, 42 gph
- For 12 volt electrical systems only
*Tech Tip: This pump mounts easily underneath the battery tray or along the passenger frame rail. The Webber has a smaller bowl reserve capacity than the factory carb, and under hard acceleration, the factory fuel pump has trouble keeping up with fuel demand. During a highway passing scenario with a high fuel demand, stumbling can occur as the carb starves for fuel. The electric pump flows enough fuel to keep the bowl at the proper level at all times, but at a low pressure, so it doesn't overcome the needle and seat. A pressure regulator is not required for this pump.

 

[brian]

been running webers on both the 87 and 75 for 15 plus years, with oe fuel pumps.
i played games with in line pressure regulators, in the end it was just the pump and the carb....no issues.
if you're concerned with fuel pressure at the carb, just use a 60 series fuel pump with the by pass line and return line to the tank.

 

[Solace in Solitude]

I love my Carter electric pumps and love no longer having to worry about item pump failure dumping fuel in the crankcase.

@bikersmurf has been running a Carter for 20+ years... I've been running a pair (one per tank) for a couple of years... the pair provide almost instantaneous pump redundancy for emergencies that may arise.

@reddingcruiser is correct... they push fuel great, but suck at sucking...mount it close to and below the fuel source and it will self-prime.

Electric pumps can be purchased by PSI/delivered... IIRC my '78 pumps are Carter P4070 pumps... 3-5 psi... for Aisan oem carb.

I would expect electric pump failures to occur, either completely, or intermittently, when under load (uphill, pedal to the metal)...when the carb secondary expects 'mass' fuel... such a failure clears immediately, when the 'load' is removed.

That is NOT what you've described... I think @B y r o n has more accurately pinpointed your problem.

I'm more comfortable, alone, in very remote locations, with dual electric pumps than I ever was with a single oem mech pump... but, to each, his own.

 

[Solace in Solitude]

Can't edit on my iPhone

'Item pump failure' ABOVE should be 'oem pump failure'

 

[bikersmurf]

@pngunme is correct, 21+ years with Carter no problems.

My son had a Mr Gasket one like yours... I wouldn't trust it further than I can throw it. There's a reason Carters are sold for marine applications... and it's not because they're cheap.

 

[FJ4013]

@pngunme is correct, 21+ years with Carter no problems.

My son had a Mr Gasket one like yours... I wouldn't trust it further than I can throw it. There's a reason Carters are sold for marine applications... and it's not because they're cheap.

They certainly don't have the highest reviews I've seen. What other electric fuel pumps are recommended that are at least more dependable?

 

[FJ4013]

I love my Carter electric pumps and love no longer having to worry about item pump failure dumping fuel in the crankcase.

@bikersmurf has been running a Carter for 20+ years... I've been running a pair (one per tank) for a couple of years... the pair provide almost instantaneous pump redundancy for emergencies that may arise.

@reddingcruiser is correct... they push fuel great, but suck at sucking...mount it close to and below the fuel source and it will self-prime.

Electric pumps can be purchased by PSI/delivered... IIRC my '78 pumps are Carter P4070 pumps... 3-5 psi... for Aisan oem carb.

I would expect electric pump failures to occur, either completely, or intermittently, when under load (uphill, pedal to the metal)...when the carb secondary expects 'mass' fuel... such a failure clears immediately, when the 'load' is removed.

That is NOT what you've described... I think @B y r o n has more accurately pinpointed your problem.

I'm more comfortable, alone, in very remote locations, with dual electric pumps than I ever was with a single oem mech pump... but, to each, his own.

Yes, what Byron has said was accurate, however, the engine cut off has occurred when I am both coasting along at a moderate RPM rate AND when I am under increased throttle. On the really hot days with high humidity I notice when shifting into 3rd gear I need to give it more throttle to get up to speed and during this shift I notice engine power loss (near to complete shut down) as well. The issue I am experiencing is a combination of both what Byron described and what you describe as "heavy load".

On another note how exactly would I configure and hook up a dual electric fuel pump system you reference? Thanks.

 

[bikersmurf]

He has one for each fuel tank. Not sure exactly how his are plumbed, but my plan was to have a filter, the pump, a one way check valve, and then into a Y... duplicated for each tank going into the same Y. So long as there was fuel in both tanks, you would have a redundant system. If you one pump fails and the other tank ran out, worst case... swap the plumbing/pumps and you'd be back in business.

I've considered this, rather than carrying a spare in the tool box, because Murphy is never far off. If a pump is going to fail, it'll do so when the small creek you crossed on the way in turned into a 4' deep river and you're in the middle. I'd rather just turn on the other pump than go swimming to repair it. The other reason... my current pump is 21ish... and everything fails at some point. The block heater was 46 when it broke... first F was 22, first SBC was 48. How it's maintained matters... but sooner or later, things break or need to be rebuilt.

 

[Solace in Solitude]

Two tanks... each with an oem fuel sender... MT=main tank; AT=Aux tank.
One oem fuel gauge.
Two fuel filters... MF & AF.
Two Carter P4070 electric pumps... MP & AP.
One Pollak 42-159 6-port switching valve... POL
One Carter Oil Presdure Safety Switch. OPSS.
One Pollak DPDT (double pole double throw toggle (ON-ON) switch... up for Aux tank, down for main tank... DPDT

Note: Pollak 42-300 includes Pollak, wiring interface, DPDT, and toggle label.

Line Routing:

MT feed to MF to MP to POL

AT feed to AF to AP to POL

POL to CARB feed port

CARB return port to POL

POL MR(master return) to MT teturn

POL AR (aux return) to AT return

Wiring:

There is a very good schematic (lines and wiring) for the Pollak 6-port switching valve, in the web... but I can't find it right now, using my iPhone.

I'm not going to try to describe the wiring without a schematic... too confusing without visual aids.

The DPDT is used to select the active tank...

The OPSS deactivates the fuel pumps, when the engine oil pressure falls below 2 psi (IIRC)... it also allows the ignition to crank and start the engine when there is no oil pressure.

The Pollak switches the feed and return lines... activating the lines for the selected (active) tank and deactivating the lines for the inactive tank.

My tanks both use oem fuel senders and share the oem gauge.

The Pollak also activates the selected tank's fuel sender.

If you are serious about going this route, I'll find the schematic, when I have computer access again.

HTH

Note: I also carry a spare for every part of my fuel system... as well as a roll of soft fuel line and my oem mech pump... so, I have even more redundancies... hopefully more than I ever need...