Hello everyone, I've lurked around here for quite some time, learning as much as a i can, never really been able to contribute that much. Over the last year or so I've had an issue recently with my truck taking a long time to start. It would take between 7 to 30 seconds of cranking. It seemed like it was losing prime as the primer was always soft. I sent it to the dealer back in march to have the injectors tested with 102617 miles. They came back in great condition and dealer suggested a new filter head and hoses from the filter to the tune of $1089.00. I replaced the hoses myself as I had done the MA filter rebuild before sending it in. The problem has gotten worse through the summer. Thursday I installed an AirDog 100 hoping that the added pressure would show where the leak was coming from. It helping in that it would get it started, drove about 6 miles to Home Depot and wouldn't start when i wanted to head home. Onstar gave me a code of P1093 low rail pressure. Reading and researching it sounds like the Relief valve isn't a big issue on these trucks as much as the later versions. i disconnected the FPR on the back of the CP3 to try and get it to give max pressure and still could not get it to start. This morning i disconnected the return line to see how much fuel was returning to the tank.
This is where I disconnected the return line. The following picture is the amount of fuel after one minute of the Airdog running with the key in the on position.
This is the amount of fuel after cranking for 10 seconds.
Does this look like an unusual amount to be getting returned? I can't seem to find a part number for just the relief valve itself. I have been able to find the entire distribution block that the valve is attached too. I'm not opposed to just going to a plug and plugging it off, but I'd like to try and keep the valve intact if possible. It never smokes or has had the oil level rise indicating any injector issues. I rarely drive the truck but when it runs its like a top. Currently it has 103,598. I can't imagine that since march and only 1000 miles or so it developed an injector issue. I bought the truck with about 55,000 miles on it, put the Banks and exhaust on at about 60,000 miles, the Nicktane at around 75,000 and have been running Optilube every tank since around 90,000 miles.
Long post but i wanted to get plenty of information out there. Trying to get this fixed without throwing money in the wrong direction, any help is appreciated.
This is where I disconnected the return line. The following picture is the amount of fuel after one minute of the Airdog running with the key in the on position.
This is the amount of fuel after cranking for 10 seconds.
Does this look like an unusual amount to be getting returned? I can't seem to find a part number for just the relief valve itself. I have been able to find the entire distribution block that the valve is attached too. I'm not opposed to just going to a plug and plugging it off, but I'd like to try and keep the valve intact if possible. It never smokes or has had the oil level rise indicating any injector issues. I rarely drive the truck but when it runs its like a top. Currently it has 103,598. I can't imagine that since march and only 1000 miles or so it developed an injector issue. I bought the truck with about 55,000 miles on it, put the Banks and exhaust on at about 60,000 miles, the Nicktane at around 75,000 and have been running Optilube every tank since around 90,000 miles.
Long post but i wanted to get plenty of information out there. Trying to get this fixed without throwing money in the wrong direction, any help is appreciated.
