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hard starting with fuel pressure


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Ok found out my truck is actually having a hard time starting with fuel pressure showing on the gauge. Never had this issue before and dont know how long its been going on.I have remote start and almost always use it. :cool: Until my truck gets to slightly under 1/4 tank. I have a bad cut DS so at times under 1/4 tank it will start then stall or not start till I prime the fuel system with the key bump trick. Well last 1/4 tank I remote started it watching the gauge. Started up as normal but seemed to take a bit longer to get FP up. Ok I says. No more remote starts till fill up. Next day I prime the fuel system first, it cranks a couple seconds then starts. :think: Let it idle a bit shut off and restart with priming, fires right up. Repeat with priming more cranking.Now IIRC a torn or cracked diaphragm will cause this correct? The articles IIRC mention it being a problem when hot. This was first fire of the day.Reason is I am starting to suspect a tired VP44. Fuel economy isnt what it was, wife noticed a different idle, which now that I think about it it does. I did advance the timing on the smarty to level 4 recently and it started the stalling going into gear thing...again. So we decided to start a VP44 nestegg for when it goes. Just wondering if this new hard starting is another hit against a tired/worn out VP. Truck drives fine, has power and no trouble starting cold or hot, as long as I dont pre prime the fuel system.

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Fuel pressure (idle, cranking, and WOT at highway speed)?Error codes?I would consider re-doing the drawstraw right. That would help a bunch on your problems being it acts like its losing prime because of the bad drawstraw. Or other plumbing issues allowing air to leak back in. Being you have no fuel pressure at start up this points to a air leak more than a VP44 issue.

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Ok posted my 1st YouTube video! Lol The draw straw has been like that since I put it in about 7yrs ago. The 1/4 tank is getting old. I put a DS V? Iirc. The draw straw used to bypass the intank pump. Yes I have 2 draw straws. The original that you drill a hole in the top and drop it in through a grommet. The second one that uses the fuel module is sucking air somewhere. That is causing hard starting all the time. The truck did start with fuel pressure back then. About year ago. I have videos here but the cell phone shot crappy vids. I even hooked up a clear line from the filter to the vp and you could see air in the line as it was running. Air is coming from in the tank somewhere. So I went back to the original draw straw. Lift pump is a Walbro gs392. Wot pressure is arround 12 idle is about 15. If you can hear it the first start attempt is priming the fuel system, second is not. Noticeable difference in cranking time. Yes the fuel pressure gauge is on my knee. Lol. Another project is making.a fiberglass gauge pod and pulled the gauge out of the cubby hole where it was since I had the dash rolled back installing my alarm. Oh yea codes: 1693, 1694 Ok the vid http://youtu.be/yjg8eECzfbw

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well there is your problem :) you are pulling air from somewhere in the tank. fix that and see what happens, (not trying to be a smarty):doh:anytime you introduce air into the system it will eventually be pushed to the vp and cause rough running/no start (if enough air). even my recent LP swap 3 days later had a bubble that worked through the system from priming that the vp hiccuped and bucked the truck a couple times then cleared it.

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I don't have air in the system with the original draw straw. Even sitting overnight supply line was full. The air was with the modded fuel module. Verified with said clear hose. It does this hard starting while primed, with a full tank as well.

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It is a tight tc. Got the tranny done in 05ish. Truck started dieing again once I readvanced the timing with the smarty. However it is something I can check to see if the cranking with a primed fuel system changes.

The dieing going into gear is a separate thing. I hope.

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It is a tight tc. Got the tranny done in 05ish. Truck started dieing again once I readvanced the timing with the smarty. However it is something I can check to see if the cranking with a primed fuel system changes.

The dieing going into gear is a separate thing. I hope.

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It seems to start quicker with no fuel pressure than with fuel pressure. Is it the same on both hot and cold starts? If so I think that is pointing towards a weakened VP from what I have read. The truck acted different on the 2 starts. Normal operation if your pump is controlled by the ECM would be key on and quick bump in pressure then back to 0 pressure, then key to start and you should see about 1/2 pressure until engine starts up, then full pressure. If you bump the started with no engine start you should see full pressure for 20 to 25 seconds.

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That is what I noticed as well about the way it acted when it had pressure vs when it did not. Only reason I have come across was a torn or cracked diaphragm for the change in starting. A weaken VP sounds viable as well. Other then the starting issue truck runs great. I am curious to see if changing the timing changes the dieing going into gear. That's a separate issue. I think. :)

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