My truck is a 2001 with the 3.9, 5 speed manual, 122,700 miles on it. I live in Florida and hardly ever have any problems with cold starts. Usually this time of year our high temps are low to mid 70's, maybe it gets down to low to mid 50's at night. But for the last ten days or so it has been very cold here. I live right in the middle of the state, near Orlando. It was in the low 20's here each morning the last week or so and I had frost all over the truck.

During the cold snap my truck was a bit slow to start. Took about 4 or 5 seconds to start. Usually it fires right up in about one second. I just figured it was the weather or maybe the battery was a bit low when it is cold. I checked the battery day before yesterday, it has 12.6 volts with the truck not running and 13.8 volts when the truck is running. Last night it was warmer, I guess the low temp was 50. Truck still took about 5 or 6 seconds to start this morning. But it starts right up like always in the afternoon when I head home from work. And it is running well too, no hesitation or cutting off. It has good acceleration and power and I average about 17 mpg, which I attribute to the weather and the ethanol in winter blend gas.

Plugs, wires, cap and rotor have 13,000 miles on them. Anybody have any ideas or have this problem before? I figure if the fuel pump was going bad or the fuel pressure regulator was bad I would have the problem all the time. I appreciate any help or ideas here.

Jimmy

 

Well I found out what's wrong. It's the check valve in the fuel pressure regulator. I have a good 49 psi at the fuel rail when the truck is running but when I shut the truck off the pressure was at 26 psi and still falling within about 3 and a half minutes. A new assembly with fuel filter, regulator, pump and sending unit is $225.00 at Autozone. I just hope I can R&R the bed by myself, I don't have any help here. I am thinking I can just unbolt it, slide it back far enough to swap the pump and hold it in place with ratcheting tie downs, then slide it back into place.

Jimmy

 

any chance your check valve is just dirty and that's what alows it to hold open and the fuel to drain back? that's gotta be a cheaper easier fix.

 

The check valve is an internal part of the regulator assembly. The only way to replace it is to replace the entire fuel pump assembly. You can buy the fuel gauge sending unit separately and replace it by itself if it ever goes bad. The new pump has the pump, pressure regulator and the sending unit all together as one unit. Even if I could just do the regulator by itself I would not because this is surely one job I don't ever want to do again. I am removing the bed instead of dropping the tank, and took a break to go pick up the new pump and eat. I almost have the bed free to pull off the frame.

I got my pump at Advance, there was a 20% off discount this weekend on parts you buy online. They had it sent in from the warehouse and called me to let me know it was ready an I ran down the street to get it. I saved 45 bucks on the new pump, and the guy at Advance was really helpful and great about helping get the pump here for me. I just have to get the rest of the job done now.

Jimmy