Hey Gentlemen, I am back I just installed a new VP and everything was back to normal for a couple of weeks ,I started to notice the extened cranks, dont get me wronge this new vp flips over 10 times better than the old one but not like it did when first installed ,it takes about 1 complete or 2 complete starter turnovers or around 1 full second to fire up ,when it used to flip over right away ,any thoughts or ideas ,would it be because the fuel is not heated anymore ?

Good to see you are up and running again. I have a similar issue since just before I installed my new injectors. Mine was due to fuel leaks that got worse after the install. These were quite evident since I could see fuel on the engine and the ground. The return line on the back of the head and the tee that joins that and the return line from the vp was a major culprit. I got all of the leaks fixed, but still experience a longer start of maybe 1/2 a second, where it used to take a quarter second. I am suspecting an air leak some where letting a little fuel drain back to the tank. Next time you start it bump the starter and let the lift pump run and then start it and see if that makes a differance. It is possible to have an air leak that want leak fuel or so small amount you cnat see it. As far as the fuel heater, unless you are seeing some really cold temps I dont think would be an issue.

Exactly when do you experience the extended crank? After it sits for awhile like over night or after all day at work, or only after you drive it and shut down for a short time like a gas station and re-start, or all the time? Have you done ANYTHING else to the truck? What fuel pump are you running? Do you have a fuel pressure gauge?

I have not seen any fuel leaks but I will look closer ,I have a AIR DOG ll DF 100 ,I have the longer cranks after it sets over night and when it sets all day at work ,I was looking at my fuel gauge when I start it and noticed that it take about anywheres around 5 to 10 seconds to reach 15 to 17 psi it lingers down around 5 to 8 then comes up to 15 to 17 . these longer cranks started last week or so but not much to complian, but yesterday after work is when It took longer then the 1/2 second to 1 second crank or so I know there is something wronge when I installewd the new VP it fired up like I had a new truck up untill now.

I am experiencing the same thing,longer than normal but only 1/2 second or or so. But there does not seem to be anything common about when mine does it. I pretty sure it is an air leak somewhere. When I park up hill for more than 4 hours it will take a few seconds for it to start. If I cyle the lift pump and start it she fires right off. I to am nor seeing any leaks any where, but feel it is so small that maybe no fuel is getting out due to the consistancy of the fuel versus air. I have heard of some folks having problems with the AD quick connects leaking but I am not seeing any fuel at those connections. For now I am not to worried about it as long as it does not get any worse and will deal with it when I get my truck back home from Iowa.

jasvan10, because of what you described, I fairly positive that you have an air leak. Not too uncommon for this to happen and there is a few common places to start looking. The return line banjo bolt at the back of the cylinder head and the T fitting just below the banjo can come loose. Along with those, you really should look at ALL fuel line connections, especially if you just worked on the fuel system. If you live where corrosion is an issue then look at all metal fuel lines for pits and cracks. As mentioned, a leak doesn't have to constitute fuel visibly leaking but merely letting air enter. The fuel system MUST stay completely sealed and retain a "prime" otherwise the fuel in the lines will escape following gravity to the lowest point, which means it will try to run back into the fuel tank. For that reason a indication of a leak is tested by parking the truck for say overnight with the nose pointing downhill so that the fuel tank level is raised which means that the fuel remains in the fuel lines and starting should be normal. This is also why the truck will start if the fuel pump is allowed to cycle before starting, because the pump is re-priming the system. Depending on the severity of the leak, sometimes its not that easy and cause a longer extended crank. If you cant find the leak then I'd splash warn/hot water on all the fuel fittings, let them dry well, and then try baby powder.dripley, I cant say for sure why you have the extended crank problem since your description isn't as definitive. You mentioned it happens all the time and for an air leak to cause a hard start only after short stops would mean a severe leak which would also mean obvious leaking which should be easily identifiable. Is there ANY specific time it hard starts or is it really just all the time? If you think its possibly the fuel tank quick connection then when parking with the truck uphill, you should see fuel trying to escape at the fuel tank. Maybe not a lot but when all that fuel is bearing, you'd think you'd see a little wetness. You might want to check the fuel line places I mentioned above too. I have also heard of guys replace a small section of supply fuel line up close to the VP with clear hose to see if there is bubbles in the fuel. I know thats not something easy to do with JIC fittings and the fuel line you probably received with the fuel pump but I thought I'd throw that out there.

What I am experiencing is instead of starting instantly like it used to is that it sometimes takes 1/4 to1/2 second to start. Kind of hit and miss when it does it. but for the most part starts just fine. It is more nusciance than anything.The other day when i left work after the truck had been sitting for half a day and it took 3 or 4 seconds to start and the next morning it did it again. Both time on flat ground. Has not done it since. that was definately odd. When I park at my brothers house I am sitting nose up about 1 foot and it will take a few seconds to start after sitting for 5 or 6 hours. This is all telling me I do have an air leak some where, but it is not constant. One day it will do it the next it wont.I installed new injectors about 4 or 5 months ago and had leaks on all the connector tubes plus the return tee and the bolt on the back of the head. Left a puddle of diesel every wher I stopped. I reinstlled the injectors and now they are dry as a bone. I replaced the sealing washers on the bolt and put new orings in the tee and they are dry as a bone also. No fuel is reaching the ground I have seen no fuel on any my connections. I will admit I need to look at it much closer but that is going to have to wait untill i get her home. If it gets worse I will have to check it better at the RV park, but for now it is just a small annoyance.

thanks for the replays I will have to check the return line and connections of the original fittings everything else is new ,I know now after installing the AIR DOG ll I cannot run it passed 1/4 tank or I will loose fuel pressure with the fuel sloshing around.I been working long hour and weekends I will have to look at it when the crazy- ness stops ,I will try parking it with the nose pointing down and see if that helps any

--- Update to the previous post...

Have another question after the airdog ll was installed I discontinued the original fuel filter and housing ,does anyone know what the factory fuel filter micron rating is and the factory airdog ll , I am wondering if I went back to the factory filter micron rated into my airdog ll , If it was 10 micron filter, it increase fuel flow and pressure then the 2 micron rated filter would. if I am running a 2 micron filter it would clog faster then the 10 micron filter maybe this is why I am having harder starts ,I am just thinking out loud does this make any sense just asking , since I just install approx 2months ago the original fuel pump had a screen on it before it was filtered now it don't so the new pickup tube sucks up all debri in the tank and it goes right to the air dog ll filter ,to me it would clog faster ? any thoughts

Have another question after the airdog ll was installed I discontinued the original fuel filter and housing ,does anyone know what the factory fuel filter micron rating is and the factory airdog ll , I am wondering if I went back to the factory filter micron rated into my airdog ll , If it was 10 micron filter, it increase fuel flow and pressure then the 2 micron rated filter would. if I am running a 2 micron filter it would clog faster then the 10 micron filter maybe this is why I am having harder starts ,I am just thinking out loud does this make any sense just asking , since I just install approx 2months ago the original fuel pump had a screen on it before it was filtered now it don't so the new pickup tube sucks up all debri in the tank and it goes right to the air dog ll filter ,to me it would clog faster ? any thoughts

Filter flow isnt the problem. You can run through the OEM filter housing with an Airdog if you choose but its not really necessary. One reason to utilize the OEM filter housing would be for the fuel heater. I've even heard of guys not using the OEM filter but just running through the empty housing. Others have argued that you could cause fuel flow turbulence by doing that but I cant imagine this remotely becoming an issue. But back to the hard start issue..... Just know this, if the fuel system is not retaining that necessary prime then it will cause a hard start issue after the engine has been sitting for a period of time, like all day at work or all night. Just try parking the truck nose downhill and then see what happens.

I will try that, parking the truck with the front down hill , OK if it starts to crank over consistently ,is this still a air leak between the VP and air dog ll or is it inside the VP which is new? or where?

You have an air leak which wont always show up as an fuel leak. What you need to do is to just start at the injectors and work all the way back to the new air dog. Just turning the wrench on every fitting. You will find one that isnt tight. What I do is to loosen the fitting then snug in back down. If you need to know this is how I found my hard start that was random too. Scooter

For the last 3 days now I have been parking my truck with the nose pointing down in the driveway and at work I park in a parking lot that has a slight slope so when I park the nose is pointing down also ,I have noticed that it starts right up without any extended cranking at all is this still a air leak or is it something else?

For the last 3 days now I have been parking my truck with the nose pointing down in the driveway and at work I park in a parking lot that has a slight slope so when I park the nose is pointing down also ,I have noticed that it starts right up without any extended cranking at all is this still a air leak or is it something else?

Read my previous post (#6) in this thread and that should answer your question.

That is a sure sign of air getting in somewhere. That is my issue also. I want do much about it until I get my truck home in a couple months. Check the return line in back of the head and the tee it goes to, that was a big part of my problem. Then you just have to back track the fuel system until you find it. Since air can get in and not let fuel out. it might not be a lot of fun.

Even though fuel basically wont escape and air is allowed to enter, that doesn't mean that a little diesel wont work its way out. Thats where baby powder can help. Clean the fittings with warm/hot water, dry completely, apply baby powder, look for leaks.