look at post #9

buy the way it looks you will have to pull the banjo bolt out and find a way to block the hole in the fitting(the t). I would say like a 3/8 bolt two washers and a nut and make a gasket out of like a piece of cardboard from the back of a noetbook to go between the washers and the fitting. Then put a piece of hose over the fprv like I said before, the hose will have to be pretty big like a 5/8 heater hose. that is what it looks like to me but if anyone else has a better idea giver a whirl

there is a way to test it, i just cant remember the steps ive only read up on how to test it on a lb7 once, but the amount of time it takes to get down there and test it just spen 5 more minutes and shim the darn thing

Okay while I was gone out in the garage working on this thang, You guys were trying to help me out. THANKS!!!! Now what I just did was I looked at that link on post 9 and went out to the truck and I found it. I pulled it off and shimmed it. Used 3 washers and put it back together and guess what?.?.?.?. IT STILL IS NOT BUILDING PRESSURE!!! Is there anything else it could be other than the PUMP?

what kind of pres. does it build when you are in park and rev it up. what kink of pres does it make at idle?

Read my post #8.

besides it being injectors it would be the pump being bad.

there could be a small chance of it leaking out under the injector lines that go in the valve covers, but you would also get diesel fuel in the oil as well. there is a test that can be done to see if that is happening is to jack up the rail pressure at idle and let it sit for 5 minutes and see if the oil has risen.

but other than that its pointing to the pump.

I dont know it will make the truck do what it is doing but my service manual says that one thing to check is that the fp senson is reading correct 1.1 to 1.8 mpa with the truck off

The only time this low pressure happens is when the desired goes above 14k to 15k and above...at that very time the actual drops to 3k or 4k psi and even sometimes gives a low pressure in fuel rail code. I dont remember the code number.

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Well you have been with me from the start of this and I thank you for you help. You know everything I have tested and how...all the results and symptoms, you dont think I have missed anything do you? It just seems so odd that when to builds the 15k and then just drops off to 3k all at once.?.?.?

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Oh and I just changed the oil and there is no fuel in the oil. 6 months ago dealer installed all 8 injectors.

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Also just to let you know alittle more about this, it runs great as long as you dont get into the throttle like 1/2 peddle or more. That is about where the tech II shows the desired going over the 15K psi and higher.

I dont think it is the pump because the pump would just stop building pres not dump it like what is happening, unless it has somthing to do with throttle position sensor but you think it would throw a code. What year truck was the fpr you tried off of.