I just tested the fuel pressure on my truck and the results are a bit confusing. First, some background: I just bought this 01 Ram 2500 with 215K miles. Previous owner said the VP and lift pump are original and he never had any problems. I'm a bit skeptical because from what I've read here, not too many stock lift pumps ever reached anywhere close to 215K miles.

In any case, I have a list of things I want to do to the truck of course, first on the list was testing the fuel pressure. I ordered the Vulcan test kit from Geno's Garage and it just came in. I connected the test gauge to the schrader on the VP, opened the valve and then turned the key to the run position. There was an initial bump of pressure but it then returned to 0 with the engine off. I then started the engine and was relieved to see about 12 psi at idle. Unfortunately that only lasted for about 10 seconds before the pressure dropped to about 3 psi, still at idle. Stepping on the accelerator lowered the pressure even more.

So what's going on? If the lift pump is bad, why did I get 10 seconds of 12psi? Has anyone else seen this? For now the truck is parked until I get this sorted out. I do plan to upgrade to a FASS or Airdog anyway, but I didn't expect to have to do it immediately. Tomorrow I'll change the fuel filter and see if that makes any difference. In the mean time, I'll be doing a bunch of reading here!

 

Well I for one would suggest pulling the pump off and checking the screen inside the pump. What can happen (experiance here) is that after awhile the screen will trap fines (small bits of junk) and what will happen is that after the truck is shut off the fines will settle but once it is cranked they will suck back into the screen.

Had this happen on me and when I pulled the screen out mine had a hunk of the fines stuch together about the size of a marble come out. My stock is still on the truck minus the screen and it's still going strong after 190'000 miles (with the help of the holley). I think that alot of the problems with these pumps are due to the screen clogging up which is pointless to have on them since the filter will catch anything that size.

 

Thanks! That sounds like that might just be what the problem is. I'll check it out tomorrow and let you know.

 

Where is this screen?

 

If you remove the pump, the mounting studs are the bolts that hold the top of the housing on. I think that they were 13 mm take those out and remove the top plate. Make sure that you have it upside down or the vanes in the pump will fall out. On the inlet side you will see the screen all it takes is the point of a knife or pick to get it out. After you take the pump off, remove the banjo bolts, and get it out just wack the inlet side against the palm of your hand or a piece of wood and see what you get (not too hard though).

What makes no sense to me is that all the other pumps recomend that you filter before the pump so that the screen doesn't get clogged (voids the warrenty if you don't) and our trucks come from dodge with the filter after the pump. Thats why none of my pumps have a screen in them.

 

Makes lots of sense to me.

 

RDMueller, If you haven't decided on a pump yet I can send you a write up on how to do a Holley blue and big line install. I spent around $100 for the pump and the parts for the big line also. Just a thought.

 

Well, I am still trying to decide (I've been reading 100's of posts here for the past few hours). I had thought it would be either FASS or Airdog and after all my reading tonight I was leaning Airdog 100.

$100 for the Holley blue sounds really good, but will it do as good a job? Is it just a pump and you stick with the stock filter? Another thing that might be a deciding factor for me is time to install. I will do it myself, but my time is kind of limited right now plus I have other things I want to do to the truck as well. It does seem like the Airdog or FASS install could be a full day project. How long did it take you to do the Holley Blue?

 

Well the pump only cost around $45 and the time for install was around 4 hrs but that was with putting the big line kit on also. Mine holds arond 28 psi its run through a relay so that it only comes on when the original pump would also. I'll send you the write up that I did and you can see if it's something you want to get into. I did it to save some cash got that so that I could buy injectors also instead of just a pump.

 

Update...

Today I had a bit of time and decided to at least change the fuel filter to see if that made any difference. It looked like it hadn't been changed in quite a while - it was dark black. After installing the new filter I ran the LP a couple of times to purge the air and then had a sustained 12 psi with the LP on and the engine off. I then started the engine but it only ran for a few seconds and wouldn't restart. Most likely I just need to bleed air from the injection lines. Once I get that done and have it running again, we'll see what the idle pressure is now.

 

woohoo, 12 psi at idle!

Today, I pulled the Carter LP to check the screen. It was squeaky clean, not even one bit of debris. In fact, it looks to be in pretty good condition (see pics) considering it has 215K miles on it. I still find it kind of hard to believe, but the previous owner said he never had to replace the LP or VP44.

I put it all back together, bled the air and started it up. Now I'm getting 12 psi at idle. The problem had to be the dirty fuel filter since there wasn't any blockage on the LP screen. Take a look at how dirty that filter was. I'm going to ask the seller when he last changed it. I won't be surprised if he says, "Fuel filter? What, are you supposed to change those or something?"

 

Glad you got it running.

Your new filter will look just like that in about a month. It's just the fuel changing it's color i believe. I can still see white in the picture of your old filter so I'll bet the filter is relatively new. Could have been a bad tank of fuel and in fact plugged the filter.

Good luck.

**edit**

On second look at the BIG picture that filter is way plugged.

 

RDMueller - Glad to hear you got it running...... But FWIW, the Raptor 100 only took me a few hours to install. It's very simple and the instructions are very informative.

Night Rider - A Holey Blue for $45????? Where did you find that? Summit sells them for $132.95. And they almost always have the best prices.

http://store.summitracing.com/partde...5&autoview=sku

And did you make your own Big Line kit? Vucans will run you $114.99.

http://www.vulcanperformance.com/ser...er-Pump/Detail

After adding up the above cost and considering the 50/50 mix on the longevity of the Holly Blue, I'd be considering the Raptor 100. Not only do you get the pump with a LifeTime warranty, but also the BigLine kit from the tank to the VP all for under $400.

 

It does seem like a lot of people are using the Raptor 100. Looks to me like it is made by the same company as the Airdog, Pureflow Technologies. So the raptor is about $100 less the the Airdog, but is only a pump, right? What other considerations should I be looking at when comparing the two?

JPR Ram, you said it took a few hours to install the Raptor, do you know if the Airdog would be a much more complicated install?

 

Well, the AirDog will take longer. You'll have to drop the fuel tank so you can drill a hole for the DrawStraw. And also attach a return line from the pump/filter body to a special fitting on the fuel tank filler. Where as with the Raptor, you can use the quick disconnect line on top of the fuel tank to get fuel. And there is no return line needed from the pump.

And yes, bothe the AirDog and Raptor are made by PureFlow. The AirDog is just like the FASS, well I guess you can say it IS a FASS, Fuel Air Seperater System. Where as the Raptor is just a pump. BOTH the Raptor and the AirDog come with a BigLine kit.