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-   -   1995 Inline 6 fuel problem (Injectors, pump, or ECM)??? (https://www.ford-trucks.com/forums/1172552-1995-inline-6-fuel-problem-injectors-pump-or-ecm.html)

burns5150 07-01-2012 10:07 AM

1995 Inline 6 fuel problem (Injectors, pump, or ECM)???
 
Hey guys....
My 1995 F150 (inline 6) is giving me a fit! I bought it used and I am riding it of as many problems as I can. I could have one (or all!) of three problems.....Here is whats going on....

Was told it had a bad fuel pump only, so I replaced the fuel pump with an Ebay pump. Was listed as a "HIGH PERFORMANCE PREMIUM DAEWHA FUEL PUMP MODULE E2059M" and was compatible with my truck.

...Question 1: Is this the right pump? Is this a high, or low, volume pump... and which would be needed on my truck?

I also found that the fuel line was stopped up with what looked like carbon?? I freed the line,, and have good passage now. I checked pressure on the line, at around 25-30 psi

...Question 2: I took off and cleaned my fuel injectors...they seemed to have good spray, some more than others. I hate to spend a few hunder dollars on replacing these, if not needed. I am worried that maybe the bad line could have sent more trash toward the injectors. (If the line clogged up, surely the injectors got some of the trash). Can these injectors be taken apart and cleaned a little better?

...Question 3: Could the ECM be the problem of all this, and everything else be fine?

The truck will run, but seems to be either starving for fuel or flooding itself out. It runs real good at an idle..but seems to be "bogging" when given more pedal.
Which would be a good starting point? If I start replacing everything that may not be needed, the cost would add up fast...Thanks in advance for any help, guys!

Lead Head 07-01-2012 10:41 AM

The 4.9's run about 60 PSI of fuel pressure. You've got about half that. I'd suspect a failing fuel pressure regulator or the fuel pump is faulty.

Being a cheap unit from E-Bay, it would not surprise me if the fuel pump module was faulty.

You can check by gently pinching off the return line of the fuel pressure regulator with something. If the pressure rapidly builds, then the regulator is bad. If the pressure builds very slowly or doesn't, than the pump is faulty.

DPDISXR4Ti 07-01-2012 12:39 PM


Originally Posted by Lead Head (Post 12013038)
The 4.9's run about 60 PSI of fuel pressure. You've got about half that. I'd suspect a failing fuel pressure regulator or the fuel pump is faulty.

Typical regulated pressure for a Ford engine of this era is about 34PSI. I wouldn't imagine this engine is that much different, is it?

Furthermore, if he's measuring the pressure with the engine idling, the engine will be under strong vacuum and thus measured pressure even lower.

If pressure starts dropping under load, that would point to a ruptured FPR and replacement of same would be the fix.

kd0axs 07-01-2012 01:05 PM


Originally Posted by DPDISXR4Ti (Post 12013363)
Typical regulated pressure for a Ford engine of this era is about 34PSI. I wouldn't imagine this engine is that much different, is it?

Furthermore, if he's measuring the pressure with the engine idling, the engine will be under strong vacuum and thus measured pressure even lower.

If pressure starts dropping under load, that would point to a ruptured FPR and replacement of same would be the fix.

The 300 runs higher fuel pressure than other engines. Apparently vapor lock was a problem on the early EFI 300s because of the fuel rail's close proximity to the exhaust manifold. The first fix for this was a fan that cooled the fuel rail, but in later years (I forget the exact year) they increased the fuel pressure to solve this problem. Along with the higher fuel pressure they used smaller injectors to get the proper amount of fuel with the higher pressure.

rla2005 07-01-2012 03:28 PM


Originally Posted by DPDISXR4Ti (Post 12013363)
Typical regulated pressure for a Ford engine of this era is about 34PSI. I wouldn't imagine this engine is that much different, is it?

Furthermore, if he's measuring the pressure with the engine idling, the engine will be under strong vacuum and thus measured pressure even lower.

If pressure starts dropping under load, that would point to a ruptured FPR and replacement of same would be the fix.

As noted previously the Ford 4.9L EFI engine runs a higher fuel pressure. Cut from my Ford service manual:

Engine Running: 45-60 PSI
Key ON Engine OFF: 50-60 PSI

Lead Head 07-01-2012 03:47 PM


Originally Posted by DPDISXR4Ti (Post 12013363)
Typical regulated pressure for a Ford engine of this era is about 34PSI. I wouldn't imagine this engine is that much different, is it?

Furthermore, if he's measuring the pressure with the engine idling, the engine will be under strong vacuum and thus measured pressure even lower.

If pressure starts dropping under load, that would point to a ruptured FPR and replacement of same would be the fix.

Pressure of every other engine should be 39.5 PSI key on engine off. As mentioned the 4.9s run closer to 60 PSI to control vapor lock since the injectors are so close to the exhaust.

DPDISXR4Ti 07-01-2012 10:19 PM


Originally Posted by Lead Head (Post 12013920)
Pressure of every other engine should be 39.5 PSI key on engine off. As mentioned the 4.9s run closer to 60 PSI to control vapor lock since the injectors are so close to the exhaust.

Thanks for making me a bit smarter. :) So then I presume the regulator is specific to the 4.9, yes? Any idea what year the change was made to the higher pressure configuration?


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