Well I got the AirDog 150 installed. I started out on Christmas day, but had to finish the next morning due to bad weather. Over all the install wasn't that bad and I had to do it all by myself with just basic handtools. The only part that gave me trouble was dropping the tank, but I didn't have to remove it completely because I opted to keep using my Vulcan Draw Straw. The kit was VERY complete and very well packaged. The wiring harness is very nice, but a little on the long side.

I took some pictures, but I could only take a few at the begining because during the middle and end I was covered in dirt and oil. My truck was very dirty on the bottom side due to a leaky oil drain plug but I fixed that also. I'll get the pics that I have up and I'll take some more of it completely installed if yall would like me too.

As for the fuel pressure, when I first got her running it was set dead on 21 psi and wouldn't drop past 19 at WOT. I was extremely happy! After putting a few miles on it I noticed that my PSI dropped to 16 and my needle on my FP gauge was moving back and forth so fast it look and sounded as if it was vibrating. The next day my fuel pressure was at 21 and slowly would then drop to 15, but would jump right back up to 21 and would continue to do this pattern. Now I just went out and turned the truck on and my FP gauge needle was vibrating very rapidly back and forth between 14.5 and 16. I'm confused....

Any ideas? Also my FP gauge needle was doing this vibrating and fluctuating crap BEFORE I installed the AirDog. It first started a few months ago when I was using my Holley Blue pump and Vulcan big line kit, but what I don't understand is why my FP is varying from day to day. Is my gauge bad? Should I go out install my Isolator on the gauge? Or is it just pressure spikes from the VP44?


Over all I VERY happy with my AirDog, I just wish I could get this PSI thing figured out.

 

the jumpy needel sounds like ya got some air in there from when the line was off.........bleed it out till ya get fuel

 

Nice! Definately show us some pics!

 

Are you running a mechanical or electrical gauge? If mechanical then do like Whit said and bleed the line. If its electrical you have a bad gauge or transducer.

 

I never had that problem with my air dog but use a ball valve as a snubber to make sure I do not get pulsation and only open it enough to get fuel to the mechanical gauge to start moving the needle. Ed

 

Oooohhh - pics...nice


BTW, welcome to the site Ed

 

Bleed the hose coming off the back of the gauge? or my actual fuel line?

I'm running a mechanical gauge. A DiPricol to be exact.


I just went out to the truck and recorded what the gauge was doing on my digital camera, but my computer is screwy and I can't get it to upload. When I do I'll post the video.

Also I've been battling a hard start now for over a year and I've replaced everything on my fuel system(even the VP44) but the crossover tube orings and my return line. I've been told that it's a bad oring so I'm going to change them out this weekend. Even though I've been putting it off for months I'm actually gonna do it this time. Also, I found out a while back that if my truck is parked facing down a hill it fires right up, but recently it's been having some trouble. Any other ideas on what could be going on?

 

The pulsations in the line are due to the VP filling and closing at a rapid rate and that "hammers" the gauge. Some type of snubber is needed. You can get in line, a needle valve or an isolator. The Vulcan isolators do a good job.

While air in the line can make it worse, the fuel is hammering the air....

Hard starts can be caused by a ton of things, rarely do I see a bad o-ring causing this issue. The purpose of the o-ring is seal the fuel inside the return to the back of the head. The high pressure side is sealed by a precision ground tip of the connecting tube to the injector body.

It is possible you are getting some air in the system. Usually this takes place on the suction side and I have opersonally seen it happen on a Draw Straw because the owner/ installer got the fittings "tight enough".

Many people will then point you to the overflow valve. Keep in mind this valve has an air bleed drilled into it, so it will not hold prime no matter how many times it's replaced. It is possible it's hanging open and that can cause hard starts.

High fuel pressure is the most common culprit. Usually when hot, but can be affected by the cold as well.


Dave

 

The AirDog does an excellent job at removing entrained air. Dave where is your gauge plumbed too? Like F2D4U said, you probably need to get an isolator or needle valve to calm it down. 150gph at 20psi is a pretty hard hit on the small gauge passage.

 

Thanks. Those are all very good points and I had a feeling I would need to install a isolator, but I never had this problem until I had the hard start. Also I was seeing 15 psi on my Holley Blue/Vulcan setup. When I was running the Holley it would always jump, but it wouldn't slowly go up to 21psi and then drop back down to 15 or so and the again slowly go back up to 21psi and drop back down continuously like the AirDog is doing. I'm going to install the isolator tomorrow morning if I have time before work. Any tips on installing the isolator??? Oh and I've not been running an isolator for about 4 years now.

As for the hard start I have NO idea what is causing it. Also I had the hard start before I installed the Vulcan draw straw and trust me those fittings are tight. One reason I've never installed the new orings is because when the hard starts begain it was 3 days before I installed my new injectors. So when I installed them I had to of course remove my crossover tubes and reinstall them. Once everything was reinstalled I still had the hard start. Do you have a part number for the overflow vave? Also do you have any other options as to what it can be causing this? I'm open to anything and will try anything. This have been going on since the begining of ocotober of 06' and I'm sick of it. I may just have to leave it with Jeff Garmon to play with when I go to get my head retorqued, but honestly I can't afford not having a vehicle.



It's about a foot and a half from the VP44.



Thanks for all the input guys and like I said I'm open to all options/ideas.....

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Here is the Fuel pressure video. http://video.competitiondiesel.com/v...18015f6af0.htm

I reved the engine up to 2200rpms just show yall how its acting. You can see when I do this the need is not vibrating back and forth as much, but it is still going up and dropping back down.