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charro

long crankig after vp44 and airdog install

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Hi, just joined the forum and this is my first tread.A week ago replaced my vp44 and upgraded lift pump to airdog2-165, did everything myself and truck started right after bleeding. I've been driving the truck since i got it back running and have noticed that the truck now takes longer to start. I've been searching the internet and haven't found an aswer to my problem, finally found this forum and any help would be appreciated.

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Maybe air is getting in and your prime is gone,Go over everything you did.Check all the fittings on the air dog,fuel tank,injection pump,and injectors.Check the fitting on back of the head and the T fitting.

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Hi, just joined the forum and this is my first tread. A week ago replaced my vp44 and upgraded lift pump to airdog2-165, did everything myself and truck started right after bleeding. I've been driving the truck since i got it back running and have noticed that the truck now takes longer to start. I've been searching the internet and haven't found an aswer to my problem, finally found this forum and any help would be appreciated.

If you have no codes, and you have determined that the system is not getting air into the line. The hard starting may be because of high fuel pressure to the vp44 before engine start. If when you turn on the key and the fuel pump runs for a second or two this could be the cause it's called a prime run. There are several possible solutions, you could put in a relay that is setup to eliminate the initial prime run of the fuel pump. I believe Mike (Mopar1973man) has plans for it. Or you could go to a dealer and have the latest greatest ECM flash done that turns off the prime run. Or you could find someone near you that has a smarty. With a smarty you would flash a smarty program to the ECM then flash the ECM again to put the stock program back to the ECM. The smarty not only turns off the prime fuel pump run but it will also enable the cold weather high and 3 cyl idle for you.
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If you have no codes, and you have determined that the system is not getting air into the line. The hard starting may be because of high fuel pressure to the vp44 before engine start.

If when you turn on the key and the fuel pump runs for a second or two this could be the cause it's called a prime run.

There are several possible solutions, you could put in a relay that is setup to eliminate the initial prime run of the fuel pump. I believe Mike (Mopar1973man) has plans for it. Or you could go to a dealer and have the latest greatest ECM flash done that turns off the prime run. Or you could find someone near you that has a smarty. With a smarty you would flash a smarty program to the ECM then flash the ECM again to put the stock program back to the ECM. The smarty not only turns off the prime fuel pump run but it will also enable the cold weather high and 3 cyl idle for you.

Yeah I do... Thanks for reminding me...

http://mopar.mopar1973man.com/cummins/2ndgen24v/fuel-pressure/fuel-pressure.htm

(Bottom of the page)

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maybe air is getting in and your prime is gone,go over everything you did.check all the fittings on the air dog,fuel tank,injection pump,and injectors.check the fitting on back of the head and the t fitting.

the fitting on the back of the head is on the return side. Imp would not cause this problem. My guess is its sucking air & loosing prime. You really need to know your fuel pressure upon start-up to find the problem...like how long does it take for the pressure to come up when you turn the key over
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Any codes ?

Any fuel pressure readings ?

SO motor and NEW SO vp44 ?

yes new airdog 2-165, and new vp44 from thoroughbred diesel.

will finish installing my isspro gauges tomorrow and will find out pressure readings. there are no codes.

--- Update to the previous post...

Maybe air is getting in and your prime is gone,Go over everything you did.Check all the fittings on the air dog,fuel tank,injection pump,and injectors.Check the fitting on back of the head and the T fitting.

will recheck everything tomorrow, what is the fitting on the back of the head? and wich t-fitting?

--- Update to the previous post...

Air in the fuel... Are you sucking in air from the suction line???

do you mean the one inside the tank? because that is the only thing i wasn't completely satisfied installing. I did the in-tank module modifications with the kit that came with the airdog, and did not like the design of the bracket that holds the pick up tube to the basket. Since the module compresses when it goes back in the tank the bracket bends and my pick up straw is no longer straight and the 45degree cut at the bottom of the straw is now flat at the bottom of the basket. Do you think that could be the problem?

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Did you use any sealant on all of the fittings? This happened to me when I put my system on. Thought I had everything tight. :doh: Used some sealant from Napa, one part is spray and the other is in a tube. Made specifically for diesel fuel. Used that, and haven't had a problem since. It's pricey, but well worth it when I know there is no air leaks coming from the fittings! Good luck!

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If you have no codes, and you have determined that the system is not getting air into the line. The hard starting may be because of high fuel pressure to the vp44 before engine start.

If when you turn on the key and the fuel pump runs for a second or two this could be the cause it's called a prime run.

There are several possible solutions, you could put in a relay that is setup to eliminate the initial prime run of the fuel pump. I believe Mike (Mopar1973man) has plans for it. Or you could go to a dealer and have the latest greatest ECM flash done that turns off the prime run. Or you could find someone near you that has a smarty. With a smarty you would flash a smarty program to the ECM then flash the ECM again to put the stock program back to the ECM. The smarty not only turns off the prime fuel pump run but it will also enable the cold weather high and 3 cyl idle for you.

will finish installing my triple isspro gauges tomorrow and will be getting some pressure readings. will recheck all connections as well.

--- Update to the previous post...

the fitting on the back of the head is on the return side. Imp would not cause this problem.

My guess is its sucking air & loosing prime. You really need to know your fuel pressure upon start-up to find the problem...like how long does it take for the pressure to come up when you turn the key over

will finish installing isspro gauges tomorrow and get pressure readings.

--- Update to the previous post...

Did you use any sealant on all of the fittings? This happened to me when I put my system on. Thought I had everything tight. :doh: Used some sealant from Napa, one part is spray and the other is in a tube. Made specifically for diesel fuel. Used that, and haven't had a problem since. It's pricey, but well worth it when I know there is no air leaks coming from the fittings! Good luck![/QUO

only used diesel tread sealant at the bulk head fitting on top of the module. did not use any on the fittings to the airdog or the fitting to the vp44. Did you use any sealant on the fittings to the air dog and then vp44?

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the fitting on the back of the head is on the return side. Imp would not cause this problem. My guess is its sucking air & loosing prime. You really need to know your fuel pressure upon start-up to find the problem...like how long does it take for the pressure to come up when you turn the key over

Thank you for correcting me.Yes it is the return side that will not make it lose prime.

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Any line between the pump and the fuel tank is a suction line. Being that during run the suction line will draw air in easy. Then when the vehicle is parked the line continues to suck air into the line causing the primed fuel lines to drain back into the fuel tank so the next time you start the truck it pushes the air buibble into the VP44 and makes it impossible to start. Take a blow gun and a rug and pressurize the fuel tank with about 1-2 PSI and have a buddy look over the fuel system for leaks.

Warning Icon WARNING!
Don't get to crazy with air pressure it can blow fittings about and do damage to the tank! You only need 1 to 2 PSI at the most!
This will pressuze the entire system and if there are leaks it will show. Most common leak is the quick connect fitting on the stock sender. I normally tell people not to use the fitting in the kit and just to hose clamp on the hose directly to the sender. Or avoid the whole problem and move over to a Drawstraw and be done...

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just finished installing my gauges and here are the readings: 23-24 psi idle / 22 psi wot. is this too much?tried adjusting my airdog, the instruction says that 2 full turns clockwise is about 16 psi, but on my gauge is 26 psi. Reduced 1 turn and have 23-24 psi. Even tried at 1/2 turn and only got 21 psi. my sensor is in line with a t fitting about a foot before the vp44. "isspro ev2 gauges". is the airdog 165 too much?

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I have an airdog 150 and it typically shows 20-21psi @ idle, never had a problem. This might be completely non related, but I recently had my truck out of the blue take longer to start and it was not fuel related. I had bad grounding thru my starter housing. All three bolts that hold the starter motor to the gear reduction housing together had worked completely loose and caused "hard start" symptoms. You might just crawl underneath and give your starter a good tug and make sure it is solid. GB

just finished installing my gauges and here are the readings: 23-24 psi idle / 22 psi wot. is this too much? tried adjusting my airdog, the instruction says that 2 full turns clockwise is about 16 psi, but on my gauge is 26 psi. Reduced 1 turn and have 23-24 psi. Even tried at 1/2 turn and only got 21 psi. my sensor is in line with a t fitting about a foot before the vp44. "isspro ev2 gauges". is the airdog 165 too much?

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To much fuel pressure to the vp is like punching your brother.It doesn't seem like it hurts.Over 20lbs at idle is on the fine line of hurting the vp.Hard starts will happen with 22 to 25 psi with a vp.

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Just one more thought as often the simple stuff overlooked .... Probably a fuel/prime issue .... But checked your batteries ?

i primed the lift pump before the vp44, then opened injectors 1,3,4, and bled the system and she started. i believe its to much pressure at the vp44 plus the prime run cycle. currently 26 psi.

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