Greetings :) Looking for some fuel pump help!

[NikolayVelkov]

Hey guys!

Stopping by to say a quick hello and introduce myself. I'm Nikolay and I'm from a small european country named Bulgaria. I'm also the proud owner of a September 1991 Explorer Eddie Bauer Automatic, I use it as my daily driver and I adore everything about it. I joined this forum hoping to learn more about my car and I have a couple of questions that I wanna ask right away

My Explorer needs a new fuel pump, I can hear the current one rather loudly, the fuel gauge is not working and I've checked everything apart from the stuff inside the tank itself and the car throws the 542 error code every now and then.

Now the thing is my explorer has no governor/limiter/whatever, I have hit 120mph and can hit it at any given time, I got it like this.

What I'm wondering is what fuel pump should I get, how many PSI/bars, what should be the minimum and maximum pressures. I want to retain the performance and I have money to spare, the price is not an issue. I love my explorer and I want to get the best parts possible for it.

Looking forward to your feedback

 

[Roadrunner777]

Hello Nikolay, welcome!

I suppose the obvious answer to your question is a standard replacement fuel pump assembly, and if price is not an issue, you might as well get the Ford-brand Motorcraft 6L5Z9H307D. As I recall from the years on this message board, the DELPHI HP10142 is also a great choice. People have had good and bad experiences with AIRTEX, AIRTEX seems to have a higher failure rate and trying to use a warranty from Bulgaria may be difficult. Whatever you choose, be sure it includes a new seal and locking ring. I have often seen the recommendation to change the fuel filter at the same time. I'm not sure why, but I would do it anyway.

As to specifications, if you were to try to fabricate something from generic parts... I'm looking at the DELPHI specifications for their pump. They specify an open flow rate of 24 gallons per hour, and an absolute maximum pressure of 73 PSI. There is a fuel pressure regulator on the engine that will reduce the system pressure to 35-42 PSI depending on throttle position.

But honestly, unless I were on some abandoned island and had to hack something together, I would go with the standard fuel pump. rockauto.com let me enter a Bulgarian address and they claim to ship to 300 countries. Otherwise, I presume importing items into Bulgaria is somewhat common, perhaps you can locate a service or a freight forwarder.

Best of Luck!

 

[NikolayVelkov]

Hello Nikolay, welcome!

I suppose the obvious answer to your question is a standard replacement fuel pump assembly, and if price is not an issue, you might as well get the Ford-brand Motorcraft 6L5Z9H307D. As I recall from the years on this message board, the DELPHI HP10142 is also a great choice. People have had good and bad experiences with AIRTEX, AIRTEX seems to have a higher failure rate and trying to use a warranty from Bulgaria may be difficult. Whatever you choose, be sure it includes a new seal and locking ring. I have often seen the recommendation to change the fuel filter at the same time. I'm not sure why, but I would do it anyway.

As to specifications, if you were to try to fabricate something from generic parts... I'm looking at the DELPHI specifications for their pump. They specify an open flow rate of 24 gallons per hour, and an absolute maximum pressure of 73 PSI. There is a fuel pressure regulator on the engine that will reduce the system pressure to 35-42 PSI depending on throttle position.

But honestly, unless I were on some abandoned island and had to hack something together, I would go with the standard fuel pump. rockauto.com let me enter a Bulgarian address and they claim to ship to 300 countries. Otherwise, I presume importing items into Bulgaria is somewhat common, perhaps you can locate a service or a freight forwarder.

Best of Luck!

Hey! Thank you for your detailed reply!

I have a few more questions just so I can clarify some things for myself.

From what I gather, the Ford Motorcraft 6L5Z9H307D is a fuel pump assembly that is put on the 3rd Generation Ford Ranger with the SOCH V6 produced from 2001-2012.

I tried really hard to find any specification on it and the only thing that I managed to find was this

FORD 4L5Z9H307CF, 5L5Z9H307CA, 6L5Z9H307, 6L5Z9H307C, 6L5Z9H307CA, 6L5Z9H307F Electric Fuel Pump

Notice the 6L5Z9H307D is not among those, indeed the only difference is the D at the end and the common logic would be that if C and F are the same, D should have exactly the same specs as those two.

Minimum Free Flow Rate (gph): 45 gallons per hour
Maximum Free Flow Rate (gph): 55.0 gallons per hour
Minimum Pressure Range (Psi): 125.0 psi
Maximum Pressure Range (Psi): 135 psi


Now on the other hand the DELPHI HP10142 is with specs

Free Flow Rate (gph): 24 gallons per hour
Minimum Pressure Range (Psi): 36 psi
Maximum Pressure Range (Psi): 73 psi

And it's stated on websites that it meets or exceeds the original equipment manufacture specifications.

Do you know what are the exact specs on the stock one for my 1991 Explorer and what would be best for the system overall. I do believe that 135 psi which is 9.3 bars will make the engine incapable of reducing the pressure fast enough and in turn the pressure will blow all the hoses and the fuel injectors. I think I should be looking for something around 58 to 87 psi ( 4 to 6 bars ) but this is just my opinion and I'm no specialist.

On a side note, importing into Bulgaria is fairly simple and easy the 20% VAT sucks a bit but that's Europe for you.

 

[Mbrooks420]

1991 FORD EXPLORER 4.0L V6 Fuel Pump & Housing Assembly | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

I wouldn’t bother trying to piece together something universal or “high performance”. Nothing is going to hinder the paltry 160hp the 4.0 is putting down.

 

[Roadrunner777]

The DELPHI specs are right. Going to a higher pressure or volume will only cause the regulator to return more fuel to the tank.

I'm sorry about that Ford part number, I got that from what I thought was a reputable site.

I would go with the DELPHI anyway. Whatever quality differences between it and a Factory Ford pump will be very minor if any at all. In fact, it is possible the DELPHI is better than the OEM because of improvements possible over the last 40 years.

58-87 PSI is honestly overkill. The fuel regulator will just bump it down to 40 PSI anyway, or at least try to within it's capabilities.

Let me approach this from a different way. The stock fuel pump has never been seen as a limiting factor in engine performance. I think going to a higher pressure or volume pump will do nothing for you and will be an invitation to new never before seen problems. And anyone's first response to those problems will be to install a standard pump.

I think experimentation is great. I think over-design, going a little stronger is often a good idea. But not in this particular case.

 

[NikolayVelkov]

Got it, thanks for the info guys

I'll go with the Delphi one!