Welcome Visitor! Please take a few seconds and - Joined
- Oct 19, 2007
- Messages
- 8
- City
- Pompano Beach, FL
- Vehicle Year
- 2007
- Engine
- 3.0 V6
- Transmission
- Manual
1994 Ford Ranger, 4.0L engine. 117,000 miles.
Ever since I've owned this truck, it has always started after only about a second of engine cranking. Over the past two weeks, that has changed, and it is progressively getting worse. If the truck sits for an hour or more, it takes over 3 seconds of cranking to get it to start. If I immediately shut it down and then restart, it starts up and fires in the usual 1 second of cranking. If it sits overnight, it takes about 5-7 seconds to start.
I did verify that fuel pump is doing its 2 second prime when the ignition key is turned to the ON position. Also, there is NO LOSS OF PERFORMANCE that I can notice during normal running operation, no matter how aggressively I drive or how hard I force it to accelerate. All seems normal there. I did replace the fuel filter during this diagnosis to be sure that wasn't causing the problem. That had no effect.
I decided to run some experiments and take some data. First of all, after the truck had sat overnight, I primed it 4-5 times by turning the key to ON then OFF. Then, I tried starting it an it fired right away in the usual amount of time (1 second or so). Then, I got a pressure tester and connected it to the Schrader valve on the fuel injector manifold. According to my Haynes manual, the readings for this model year were in the normal ranges. Priming brought the presure to about 37 psi. After the pump stopped, it would sit at 35 psi. While the engine was running, it was down around 28 psi (increasing slightly with acceleration). What I did notice however is how quickly the pressure decays when the truck sits off. Overnight, it pretty much went to nothing, and I was able to verify that it took about 3 primes (<key ON then OFF> x 3) to get it back to 35 psi.
So now I'm suspecting that I'm loosing fuel pressure slowly due to a leak somewhere. I don't smell or see any gas leaks anywhere in the engine compartment or along the fuel lines, so I'm thinking it could be a slowly leaking injector that apparently doesn't leak enough during normal operation to cause any noticeable performance degradation. However, I do suspect my mileage has degraded in recent months, so this may be the problem.
My questions to the community are: Are leaking injectors common given the age and mileage? I don't have any experience there. Also, could this problem be caused by a bad fuel pressure regulator way back at the fuel pump assembly? What else should I be looking for?
Thanks in advance.
Ever since I've owned this truck, it has always started after only about a second of engine cranking. Over the past two weeks, that has changed, and it is progressively getting worse. If the truck sits for an hour or more, it takes over 3 seconds of cranking to get it to start. If I immediately shut it down and then restart, it starts up and fires in the usual 1 second of cranking. If it sits overnight, it takes about 5-7 seconds to start.
I did verify that fuel pump is doing its 2 second prime when the ignition key is turned to the ON position. Also, there is NO LOSS OF PERFORMANCE that I can notice during normal running operation, no matter how aggressively I drive or how hard I force it to accelerate. All seems normal there. I did replace the fuel filter during this diagnosis to be sure that wasn't causing the problem. That had no effect.
I decided to run some experiments and take some data. First of all, after the truck had sat overnight, I primed it 4-5 times by turning the key to ON then OFF. Then, I tried starting it an it fired right away in the usual amount of time (1 second or so). Then, I got a pressure tester and connected it to the Schrader valve on the fuel injector manifold. According to my Haynes manual, the readings for this model year were in the normal ranges. Priming brought the presure to about 37 psi. After the pump stopped, it would sit at 35 psi. While the engine was running, it was down around 28 psi (increasing slightly with acceleration). What I did notice however is how quickly the pressure decays when the truck sits off. Overnight, it pretty much went to nothing, and I was able to verify that it took about 3 primes (<key ON then OFF> x 3) to get it back to 35 psi.
So now I'm suspecting that I'm loosing fuel pressure slowly due to a leak somewhere. I don't smell or see any gas leaks anywhere in the engine compartment or along the fuel lines, so I'm thinking it could be a slowly leaking injector that apparently doesn't leak enough during normal operation to cause any noticeable performance degradation. However, I do suspect my mileage has degraded in recent months, so this may be the problem.
My questions to the community are: Are leaking injectors common given the age and mileage? I don't have any experience there. Also, could this problem be caused by a bad fuel pressure regulator way back at the fuel pump assembly? What else should I be looking for?
Thanks in advance.
