fuel systems

[Hugh Tannahill]

1997 explorer awd 5.0- has no pick up, pressing gas pedal engine back fires, will slowly pick up speed. replaced maf, fuel filter, spark plugs and wires, air filter. removed fuel line from filter inserted into bottle, when I turn the key on, fuel comes out in spurts

 

[koda2000]

You need to check actual fuel pressure at the fuel rail. Seeing fuel squirt into a bottle is not exactly scientific. A '97 should have around 35-37 PSI of fuel pressure. To do this check you can borrow/buy an actual fuel pressure gauge from an auto parts store or you can get a dial type tire pressure gauge (around $5-$6) and use it, though gasoline may or may not damage the tire pressure gauge after use.

Your problem may be fuel pressure related, but it might also be caused by several other things. Is your check engine light on? Does it illuminate during the bulb check? I would think this problem would set the CEL.

If your vehicle still has it's original OE fuel pump it's quite possible it's dying. I've had to replace the fuel pumps in every one of our Explorers/Mountaineers. They all started having issues between 175,000-200,000 miles.

 

[Hugh Tannahill]

You need to check actual fuel pressure at the fuel rail. Seeing fuel squirt into a bottle is not exactly scientific. A '97 should have around 35-37 PSI of fuel pressure. To do this check you can borrow/buy an actual fuel pressure gauge from an auto parts store or you can get a dial type tire pressure gauge (around $5-$6) and use it, though gasoline may or may not damage the tire pressure gauge after use.

Your problem may be fuel pressure related, but it might also be caused by several other things. Is your check engine light on? Does it illuminate during the bulb check? I would think this problem would set the CEL.

checked pressure, 15psi, I have previously replaced just pump, but not full assembly

 

[koda2000]

15 PSI is less than 1/2 of what your fuel pressure should be. The '97 model uses a fuel pressure regulator on the fuel rail. This could be going bad, but I don't know of a definitive test for it. The fact that fuel "spurts" out of the fuel line does not sound right to me. I would think it should come out in a continuous stream. What brand of pump did you install? The first fuel pump I replaced was an AirTex brand, which are known to not last very long. Mine lasted about 1 year before I had to replace it again.

Just replacing the pump is fine as long as your fuel gauge is registering correctly. The '97 FP assembly has nothing on it except the pump and level sender.

You still didn't say whether your CEL works and/or is ON.

 

[Hugh Tannahill]

15 PSI is less than 1/2 of what your fuel pressure should be. The '97 model uses a fuel pressure regulator on the fuel rail. This could be going bad, but I don't know of a definitive test for it. The fact that fuel "spurts" out of the fuel line does not sound right to me. I would think it should come out in a continuous stream. What brand of pump did you install? The first fuel pump I replaced was an AirTex brand, which are know to not last very long. Mine lasted about 1 year before I had to replace it again.

You still didn't say whether your CEL works and/or is ON.

15 PSI is less than 1/2 of what your fuel pressure should be. The '97 model uses a fuel pressure regulator on the fuel rail. This could be going bad, but I don't know of a definitive test for it. The fact that fuel "spurts" out of the fuel line does not sound right to me. I would think it should come out in a continuous stream. What brand of pump did you install? The first fuel pump I replaced was an AirTex brand, which are known to not last very long. Mine lasted about 1 year before I had to replace it again.

Just replacing the pump is fine as long as your fuel gauge is registering correctly. The '97 FP assembly has nothing on it except the pump and level sender.

You still didn't say whether your CEL works and/or is ON.

cel is on. going to drop tank and bench test pump and check for leaks on connections

 

[koda2000]

If your CEL is on you really need to have your codes scanned. Most auto parts stores will do this for free. I'd have this done before you go through the trouble of dropping the tank.

A thought on testing the fuel pressure regulator... Most types of pressure regulators use engine vacuum against a diaphragm and the diaphragm can crack/tear over time no longer allowing the regulator to function. This can be tested with a small inexpensive vacuum pump which has a gauge on it to tell if the device is holding vacuum. You should also check your EGR valve in the same way, which might also be causing your issue.

 

[Hugh Tannahill]

If your CEL is on you really need to have your codes scanned. Most auto parts stores will do this for free. I'd have this done before you go through the trouble of dropping the tank.

A thought on testing the fuel pressure regulator... Most types of pressure regulators use engine vacuum against a diaphragm and the diaphragm can crack/tear over time no longer allowing the regulator to function. This can be tested with a small inexpensive vacuum pump which has a gauge on it to tell if the device is holding vacuum. You should also check your EGR valve in the same way, which might also be causing your issue.

I will check it out. I have an obdII tester. Thank You

 

[Hugh Tannahill]

cel is on. going to drop tank and bench test pump and check for leaks on connections

re-checked fuel pressure at rail with engine runningish 37 psi

 

[koda2000]

re-checked fuel pressure at rail with engine runningish 37 psi

37 PSI 'ish is about right for a '97. I'd check your EGR valve diaphragm with a vacuum pump next, but you're shooting in the dark w/out knowing what your codes are.