Isspro guage acting funny....and question on Airdog100

[walsey]

Ok guys, bout to pull the trigger on an Airdog 100 as soon as my tax return comes in but had a few questions. First off, my Isspro ev2 fuel pressure gauge seems to be acting funny. When I get in and crank the truck in the mornings when engine is colder the gauge will go to zero for a minute and then pop up to about 10-12 at idle which is where it normally is. No rhyme or reason though I can be driving and it will drop to zero and sometimes stay there or pop back up. My set up on the gauge is I tapped into the test port of the vp44 with a banjo/snubber bolt to a grease gun hose then to my sending unit. I used teflon tape on everything but the banjo bolt to the vp44. I hope thats a good setup but if not I need to change it which might lead to my second question. When I install the Airdog do I montior the fuel pressure from the same spot like I am now or does a fuel line run to the banjo bolt I have now. If I was guessing I probably have to get a different fitting at the vp44 but not sure.

[dripley]

your sender could be going out or you might be sucking air to cause the drop. Loose wiring maybe.The ad100 should come with all new fuel lines and fittings to install straight from the tank to the pump to the vp. If you wish to reconnect it the same way you will need another fitting. Vulcan performance is a good source for that fitting. vulcan has 90* fitting with a tap in it for a FP gauge. They also have a tapped push lock fitting you can splice into your new fuel line for the FP gauge. I believe there is a tap on the AD for a FP gauge. Ther are many number of ways to do this. Do you plan on keeping the stock fuel canister?

[walsey]

Boy that would sure suck if its the sender. The gauge hadn't been on for a month. I also noticed when the truck is idling and its at 10-12 the needle will go up and down up and down. Is that needle bounce? Its very subtle not jumping around crazy like but anyways. Yeah the stock filter canister was a question for later. I read a little into it but not that familar yet with the different ways to do it. I think I remember reading that you lose you fuel heater and water warning light by bypassing that the filter but Im not sure they are that important to me. I just want the set up that gives me the best performance from the lift pump and get find the best place to get accurate fp readings.

[dripley]

Thats water hammer on from the vp trying to beat it to death. I installed mine with a needle valve It is barely cracked open so the hammering does not come thru and detsroy my gauge. The needle valve is installed into a tapped push lock fitting spliced into the line from the canister to the VP. From what you say it sounds like the snubbber is trying to do its job. It is letting some of the pulse thru though.Using the stock canister is pretty much a personal choice. I wanted the heater and the sensor. I also get a littile extra filtration with it also. My pressure is 19 at idle and 16.5 at wot with this set up.

[walsey]

So what would be my best place to install the needle valve in my set up. I didnt tap into that line between the filter housing and the vp44. Could I add a little bit of hose between the snubber and the grease gun hose and splice in the needle valve there?

[Mopar1973Man]

Just need to ditch the grease gun hose... Use a needle valve to dampen the pulses... Like both of us we got rubber hose in the line and effects the ground plane for electric sender. I had to phyiscally solder a wire to the sender because of the rubber. Now the grease gun hose does absolutely nothing... Its the water hammer that kills gauges not vibration...

[dripley]

Can you take your snubber out and replace it with the needle valve? You could leave the grease gun hose if it helps, but like Mike says it does not protect anything. It is the hammering and not the vibration

[walsey]

I would like to figure out a way to leave the banjo bolt and also use a needle valve. I don't know enough about the needle vavle to know if I can replace it. Guess I could just take it off and tie into the fuel line between the filter and the vp44

[dripley]

One of the reasons for installing a better lift pump is the greater flow from the larger fuel lines. Next time you get a chance look at a banjo bolt and see how small of openings are in it. You can get a fitting that will increase your flow and do the same thing as the bajo bolt. I have a 90* fitting on mine with an outlet like the schrader valve in the banjo bolt(minus the guts). check out vulcan performance's big line kit and you can see the 90 Iam speaking of. It can be purchase seperately. If that is not what you want give them a call and tell them what you want and they should be able to help you do it your way.

[Mopar1973Man]

I would like to figure out a way to leave the banjo bolt and also use a needle valve. I don't know enough about the needle vavle to know if I can replace it. Guess I could just take it off and tie into the fuel line between the filter and the vp44

Here is a little vid on it...

http-~~-//www.youtube.com/watch?v=M33ZCc8b-7Q

[walsey]

Great video Mike, I called vulcan performance yesterday and talked to a fellow there and said when I was ready to purchase the Airdog I could get the hardware to setup the gauge while installing the Airdog. Couple more questions, Mike in your video I believe I saw your fuel pressure gauge drop to zero when you shut the truck off (I might be wrong) but does it. Whenever I shut my truck off my gauge stays wherever it was prior to turning the key off. Didn't know if that was normal. Two, I believe my lp is still mounted on the side of the motor. Does that make the AD install easier or harder?

[Mopar1973Man]

Mine is a true mechanical gauge showing real time pressure. Electric gauge might just leave the needle laying on the last position when the key is shut off.

[Michael]

If your gauge intermittently drops to zero then I would first check the wiring at the back of the gauge, particularly the red/yellow and green wires. Did the little black wire insertion tool have an ISSPRO logo on it? If not, it was the old version which tends to deflect too much and makes it hard to push the pins in. When using one of those I grab the wires while squeezing the connector and tool together, and pull the wires towards the orange connector, pulling them deeper into the "V" of the connector terminals.As far as the pulsations go, every VP44 truck puts them out onto the fuel supply line. As suggested, it is best to use a needle valve as an adjustable snubber. From my experience the grease gun hose offers a bit of additional smoothing when used with a needle valve, but the majority of the benefit is from the needle valve. Depending on the age of your gauge (if the "S/N" is earlier than C300) then you may have the older software version, which will allow more of the pulsations to be displayed on the gauge. Newer versions have more filtering in the software, specifically aimed at reducing the pointer motion from injection pump pulses while still showing changes like a drop in fuel pressure.Regards,Michael Pliska

[walsey]

Thanks Micheal for your input. I can't remember on the tool I will have to find it and check it out. I just bought it less than a month ago so I hope it was the updated version. And yes when I install the airdog I am going to add the needle valve into my setup.

--- Update to the previous post...

Also guys about the factory lift pump, I think mine is still on the side of the motor. Is this good or bad for the install. Ive read where people have to drop the tank or take the bed off. Just trying to learn and find out about these drawstraws and see if I need one. I believe after researching, im going to run my lines through the stock filter housing like dripley. I like the idea of extra filtration and it ain't hurting his pressure none.

[dripley]

You might as well loose the oe pump, might gain you a little room to work with the oe canister. The braket on the engine needs to stay. I believe it is covering up an opening for a mechanical lift pump. The braket did not get in the way of installing the fuel line.If you are going to use the ad100 the fuel line will connect straight to the existing fitting on top of the basket. I guess you can get them with a draw straw also. I am not very familiar with the 100. Somebody just told me the other day they could reach right in and disconnect the old line and attach the new one. I never tried that on mine, I had to drop the tank any way to remove the intank pump. It took me an hour to drop the tank the first time and 30 minutes the second time:doh:. Run the tank down pretty low if you do drop the tank.