I have read through numerous threads on the site and have come to a couple of conclusions. I either have a bad fuel pump check valve or FPR. Key on, the pressure shoots to 62 PSI, key off it drops like a rock to zero. When the engine is warm, or if it is above 40 degrees out or so, the truck fires up no problems no matter how long it's been sitting. Lately as it has become colder outside, it takes several minutes to get the truck started. I had this same issue last winter but if I parked in the garage so it always started no matter how cold it was outside in the morning. After sitting all day at work though, I ran into no start issues. I assume the cold air allows the fuel to bleed off quicker correct?

Now for the weird issue. When I turn the key on, the fuel pump primes as it should. When I turn the key off, it also primes. If I go to turn the key back on, it will not prime until the key is turned to the off position. What would cause this? Is this normal? Every other car I have owned when the key is turned to on the fuel pump primes no matter what. I read a thread that captain hook commented on and from my understanding this issue could be the result of a bad oil pressure sending unit. Did I read that correctly?

This weekend I am going to take Hooks advise from another thread and make the valve to check pressure at the pump to verify if it is the pump check valve allowing bleed off or if it is up towards the motor somewhere.

Any comments/advise on my problems are greatly appreciated.

Thanks.

 

Hi before you go crazy change the schraeder valve on the fuel line in the engine compartment were you would normaly check fuel pressure. Looks just like the one on a tire. The stem and wrench are like 3 bucks. I used one that was supposed to be chemicaly resistant from an A/C supply house. Did it in the parking lot of the place, took five min's and solved issue. Good luck from Hamptonbays.

 

Anyone else have input? Thanks.

 

Up again. Anyone have similar issues or have any input? Thanks.

 

Having similar issues if mine sits more than a day it coughs sputters etc for few miles or does it more often when cold po replaced fuel pump with a autozone one and I think pressure us bleeding off drives me nuts

I also have a fuel leak at top of tank only smell it when you fill tank to full and again only smell it till guage is off full so figure leak must be at top of tank could this be causing my pressure problem?

 

Isolating the pump IS the next step. You have verified that you have a leak down outside the spec. Time to isolate the problem and fix it.

The parts required for an adapter are detailed in the fuel pressure test procedure tech article.

 

That is the plan this weekend.

Do you have any idea on why the pump primes when the key is turned to the OFF position? After turning the key to the ON position after the truck has been sitting a bit, it will prime right away but then wont prime unless the key is moved to the OFF position. I don't understand what would be causing this.

Thanks.

 

To make you ask questions. The pump priming when turning it off isn't a symptom that has anything to do with the rapid drop in pressure.

 

Your 2000 is not equipped with the oil pressure sending unit circuit to the fuel pump. From what you're describing with fuel pump activation, it's normal, don't worry about it.

As Kyle mentioned, isolate the pump and check for leakdown in the pump. It should build somewhere between 73psi and 108psi. Pressure will drop when the pump shuts off, but it must remain above 55psi.

 

I just find it strange that the pump will only prime once when the key is moved to the ON poistion. I plan on making a trip to Lowe's this weekend to make the valve/gauge I need.

Thanks again.