Fuel Pressure and Dead Pedal
10-10-2015, 10:09 PM
#46
Registered User
Well I totally commend you on your diagnostic skills and patience. 
And yes, that test gauge is pretty handy. Cant say if its perfectly accurate or not either but thats not the point as more of what you're after is comparing the similarities between the two gauges and using their similarities as a base line.
Also, you "can" use the test gauge while driving if you want. I believe if I remember right that by pulling the hood/cowl seal loose on that side, you can run the gauge line up under the hood and it should fit when the hood is closed. DONT pinch it but if there's a little pressure on it from the hood then thats OK. Thats why the hose is so long too, so that you can hold the gauge outside the window and take it out for a test ride. When I tested mine I only went around the block so I just left the hood partially open being held down only by the security latch.
Not advised but I didnt expect 25 mph to offer much wind pressure under the hood.
And your picture of the FASS..... Wow, that looks really old. I'd think FASS may want that back just for nostalgic purposes. And your thinking about the leaking FASS causing the hard start is absolutely correct. A leak in the fuel line will stop the prime and the fuel pump can be a leak just as much as a loose fitting or pitted or cracked line can be a leak. Sounds like a new fuel pump is what you need.....if not just for sake of replacing that old one. Cant say whether or not anything will change either so replace at your own risk.
Maybe FASS will have better input after you give them the resistance readings.
And yes, that test gauge is pretty handy. Cant say if its perfectly accurate or not either but thats not the point as more of what you're after is comparing the similarities between the two gauges and using their similarities as a base line.Also, you "can" use the test gauge while driving if you want. I believe if I remember right that by pulling the hood/cowl seal loose on that side, you can run the gauge line up under the hood and it should fit when the hood is closed. DONT pinch it but if there's a little pressure on it from the hood then thats OK. Thats why the hose is so long too, so that you can hold the gauge outside the window and take it out for a test ride. When I tested mine I only went around the block so I just left the hood partially open being held down only by the security latch.
Not advised but I didnt expect 25 mph to offer much wind pressure under the hood.And your picture of the FASS..... Wow, that looks really old. I'd think FASS may want that back just for nostalgic purposes. And your thinking about the leaking FASS causing the hard start is absolutely correct. A leak in the fuel line will stop the prime and the fuel pump can be a leak just as much as a loose fitting or pitted or cracked line can be a leak. Sounds like a new fuel pump is what you need.....if not just for sake of replacing that old one. Cant say whether or not anything will change either so replace at your own risk.
Maybe FASS will have better input after you give them the resistance readings.
10-10-2015, 10:15 PM
#47
Registered User
Thread Starter
Well I totally commend you on your diagnostic skills and patience. And yes, that test gauge is pretty handy. Cant say if its perfectly accurate or not either but thats not the point as more of what you're after is comparing the similarities between the two gauges and using their similarities as a base line.
Also, you "can" use the test gauge while driving if you want. I believe if I remember right that by pulling the hood/cowl seal loose on that side, you can run the gauge line up under the hood and it should fit when the hood is closed. DONT pinch it but if there's a little pressure on it from the hood then thats OK. Thats why the hose is so long too, so that you can hold the gauge outside the window and take it out for a test ride. When I tested mine I only went around the block so I just left the hood partially open being held down only by the security latch. Not advised but I didnt expect 25 mph to offer much wind pressure under the hood.
And your picture of the FASS..... Wow, that looks really old. I'd think FASS may want that back just for nostalgic purposes. And your thinking about the leaking FASS causing the hard start is absolutely correct. A leak in the fuel line will stop the prime and the fuel pump can be a leak just as much as a loose fitting or pitted or cracked line can be a leak. Sounds like a new fuel pump is what you need.....if not just for sake of replacing that old one. Cant say whether or not anything will change either so replace at your own risk.
Maybe FASS will have better input after you give them the resistance readings.
And yes, that test gauge is pretty handy. Cant say if its perfectly accurate or not either but thats not the point as more of what you're after is comparing the similarities between the two gauges and using their similarities as a base line.Also, you "can" use the test gauge while driving if you want. I believe if I remember right that by pulling the hood/cowl seal loose on that side, you can run the gauge line up under the hood and it should fit when the hood is closed. DONT pinch it but if there's a little pressure on it from the hood then thats OK. Thats why the hose is so long too, so that you can hold the gauge outside the window and take it out for a test ride. When I tested mine I only went around the block so I just left the hood partially open being held down only by the security latch.
Not advised but I didnt expect 25 mph to offer much wind pressure under the hood.And your picture of the FASS..... Wow, that looks really old. I'd think FASS may want that back just for nostalgic purposes. And your thinking about the leaking FASS causing the hard start is absolutely correct. A leak in the fuel line will stop the prime and the fuel pump can be a leak just as much as a loose fitting or pitted or cracked line can be a leak. Sounds like a new fuel pump is what you need.....if not just for sake of replacing that old one. Cant say whether or not anything will change either so replace at your own risk.
Maybe FASS will have better input after you give them the resistance readings.
10-10-2015, 10:30 PM
#48
Registered User
Ya know, I really dont have an answer for that. My "opinion" though is that (I) you dont need all the extra filtration or the air separation gimmick. I think the stock fuel filter is fine so therefore a regular pump like the DRP should be fine. 
Air separation was a big marking deal about 5-8 years ago. Never proven to be the miracle that everyone made it out to be, but its not a disadvantage either.
I have the "older and better" Raptor 100 which was basically the same pump as the Airdog but as a stand alone fuel pump without the extra filters and without the air separation feature.
In saying that, if I was to do it all over again I would choose the Fuel Boss mechanical fuel pump system. Very cool and proven reliable pump. But thats just me and I certainly dont want to lead you astray and having you re-configuring everything on your truck simply because of what I'd want.
Air separation was a big marking deal about 5-8 years ago. Never proven to be the miracle that everyone made it out to be, but its not a disadvantage either.I have the "older and better" Raptor 100 which was basically the same pump as the Airdog but as a stand alone fuel pump without the extra filters and without the air separation feature.
In saying that, if I was to do it all over again I would choose the Fuel Boss mechanical fuel pump system. Very cool and proven reliable pump. But thats just me and I certainly dont want to lead you astray and having you re-configuring everything on your truck simply because of what I'd want.
10-10-2015, 10:36 PM
#49
Registered User
Thread Starter
Ya know, I really dont have an answer for that. My "opinion" though is that (I) you dont need all the extra filtration or the air separation gimmick. I think the stock fuel filter is fine so therefore a regular pump like the DRP should be fine. Air separation was a big marking deal about 5-8 years ago. Never proven to be the miracle that everyone made it out to be, but its not a disadvantage either.
I have the "older and better" Raptor 100 which was basically the same pump as the Airdog but as a stand alone fuel pump without the extra filters and without the air separation feature.
In saying that, if I was to do it all over again I would choose the Fuel Boss mechanical fuel pump system. Very cool and proven reliable pump. But thats just me and I certainly dont want to lead you astray and having you re-configuring everything on your truck simply because of what I'd want.
Air separation was a big marking deal about 5-8 years ago. Never proven to be the miracle that everyone made it out to be, but its not a disadvantage either.I have the "older and better" Raptor 100 which was basically the same pump as the Airdog but as a stand alone fuel pump without the extra filters and without the air separation feature.
In saying that, if I was to do it all over again I would choose the Fuel Boss mechanical fuel pump system. Very cool and proven reliable pump. But thats just me and I certainly dont want to lead you astray and having you re-configuring everything on your truck simply because of what I'd want.
10-10-2015, 10:55 PM
#50
Registered User
I've only heard limited information and experience about the adjustable FASS. Not sure it would be my first choice either. Its not "adjustable" like you're probably thinking but rather it self adjusts by some other variable input like boost pressures or something else I'm unaware of. I'm more of the "simple but works" mentality. And do ask FASS about the pro's and con's of the 95 vs the 150 because I think there's more to it than just more volume. I know there's running amperage differences but I dont know about regulator differences or anything else.....
And do ask FASS about the pro's and con's of the 95 vs the 150 because I think there's more to it than just more volume. I know there's running amperage differences but I dont know about regulator differences or anything else.....
10-10-2015, 10:58 PM
#51
Registered User
Thread Starter
I've only heard limited information and experience about the adjustable FASS. Not sure it would be my first choice either. Its not "adjustable" like you're probably thinking but rather it self adjusts by some other variable input like boost pressures or something else I'm unaware of. I'm more of the "simple but works" mentality. And do ask FASS about the pro's and con's of the 95 vs the 150 because I think there's more to it than just more volume. I know there's running amperage differences but I dont know about regulator differences or anything else.....
And do ask FASS about the pro's and con's of the 95 vs the 150 because I think there's more to it than just more volume. I know there's running amperage differences but I dont know about regulator differences or anything else.....
10-11-2015, 11:05 AM
#52
Registered User
Thread Starter
Mechanical fuel pump
Ok so you got me intrigued over these mechanical fuel pumps such as the Mitusa, glacier, or assassin.....how do they work without an electric lift pump to prime it before the engine starts? I assume it would just be a little harder to start but is that hard on the vp44?
10-11-2015, 11:33 AM
#53
Registered User
I've only heard limited talk about the Mitusa so I cant speak about that pump. Glacier is top notch and you never hear anything bad about that system. The Assassin on the other hand has had its fair share of threads over the years about issues and those members not getting proper customer service. Whether or not things have changed, I cant say. I think some people choose the Assassin because its more blingy than the other more industrial looking two.
As for how they work..... Its rarely explained that the VP prefers starting with no fuel pressure against it, AS LONG AS the prime is always maintained. Meaning the VP wont purge its own air if the prime is lost but it starts best without gobs of cranking pressure against the head. Search for "hard starting when hot" and you'll see an abundance of threads discovering this very thing.
So that said, I believe the Assassin and the Mitusa are just mechanical systems. But the FB pump system has the option to use a secondary OEM lift pump plumbed and wired in so as to make sure the priming cycle is still in affect. Also, if the FB pump happens to loose its drive belt then the lift pump can temporarily pick up the slack until you can take a second to toss a new belt on there. Its really a pretty slick setup.
In defense of the other two systems, I cant fully confirm if they incorporate the secondary pump as they may have changed their setup from the last time I researched these pumps. So do your own checking too.
One thing you'll hear about with mechanical pumps is how they "build" pressure rather than loose pressure. Thats because electrical pumps build max pressure at idle and drop from there. Mechanical is the opposite.
But there's always a con too and I "think" if I remember right, there are potentially some issues with how the mechanical pumps fit right next to the harmonic balancer. I cant completely recall what all the concerns are but I do think I remember that you cant use a Fluidampr. Again, not completely sure.....and I'm rambling on once more.
As for how they work..... Its rarely explained that the VP prefers starting with no fuel pressure against it, AS LONG AS the prime is always maintained. Meaning the VP wont purge its own air if the prime is lost but it starts best without gobs of cranking pressure against the head. Search for "hard starting when hot" and you'll see an abundance of threads discovering this very thing.
So that said, I believe the Assassin and the Mitusa are just mechanical systems. But the FB pump system has the option to use a secondary OEM lift pump plumbed and wired in so as to make sure the priming cycle is still in affect. Also, if the FB pump happens to loose its drive belt then the lift pump can temporarily pick up the slack until you can take a second to toss a new belt on there. Its really a pretty slick setup.
In defense of the other two systems, I cant fully confirm if they incorporate the secondary pump as they may have changed their setup from the last time I researched these pumps. So do your own checking too.
One thing you'll hear about with mechanical pumps is how they "build" pressure rather than loose pressure. Thats because electrical pumps build max pressure at idle and drop from there. Mechanical is the opposite.
But there's always a con too and I "think" if I remember right, there are potentially some issues with how the mechanical pumps fit right next to the harmonic balancer. I cant completely recall what all the concerns are but I do think I remember that you cant use a Fluidampr. Again, not completely sure.....and I'm rambling on once more.
10-11-2015, 12:00 PM
#54
Registered User
Thread Starter
I've only heard limited talk about the Mitusa so I cant speak about that pump. Glacier is top notch and you never hear anything bad about that system. The Assassin on the other hand has had its fair share of threads over the years about issues and those members not getting proper customer service. Whether or not things have changed, I cant say. I think some people choose the Assassin because its more blingy than the other more industrial looking two.
As for how they work..... Its rarely explained that the VP prefers starting with no fuel pressure against it, AS LONG AS the prime is always maintained. Meaning the VP wont purge its own air if the prime is lost but it starts best without gobs of cranking pressure against the head. Search for "hard starting when hot" and you'll see an abundance of threads discovering this very thing.
So that said, I believe the Assassin and the Mitusa are just mechanical systems. But the FB pump system has the option to use a secondary OEM lift pump plumbed and wired in so as to make sure the priming cycle is still in affect. Also, if the FB pump happens to loose its drive belt then the lift pump can temporarily pick up the slack until you can take a second to toss a new belt on there. Its really a pretty slick setup.
In defense of the other two systems, I cant fully confirm if they incorporate the secondary pump as they may have changed their setup from the last time I researched these pumps. So do your own checking too.
One thing you'll hear about with mechanical pumps is how they "build" pressure rather than loose pressure. Thats because electrical pumps build max pressure at idle and drop from there. Mechanical is the opposite.
But there's always a con too and I "think" if I remember right, there are potentially some issues with how the mechanical pumps fit right next to the harmonic balancer. I cant completely recall what all the concerns are but I do think I remember that you cant use a Fluidampr. Again, not completely sure.....and I'm rambling on once more.
As for how they work..... Its rarely explained that the VP prefers starting with no fuel pressure against it, AS LONG AS the prime is always maintained. Meaning the VP wont purge its own air if the prime is lost but it starts best without gobs of cranking pressure against the head. Search for "hard starting when hot" and you'll see an abundance of threads discovering this very thing.
So that said, I believe the Assassin and the Mitusa are just mechanical systems. But the FB pump system has the option to use a secondary OEM lift pump plumbed and wired in so as to make sure the priming cycle is still in affect. Also, if the FB pump happens to loose its drive belt then the lift pump can temporarily pick up the slack until you can take a second to toss a new belt on there. Its really a pretty slick setup.
In defense of the other two systems, I cant fully confirm if they incorporate the secondary pump as they may have changed their setup from the last time I researched these pumps. So do your own checking too.
One thing you'll hear about with mechanical pumps is how they "build" pressure rather than loose pressure. Thats because electrical pumps build max pressure at idle and drop from there. Mechanical is the opposite.
But there's always a con too and I "think" if I remember right, there are potentially some issues with how the mechanical pumps fit right next to the harmonic balancer. I cant completely recall what all the concerns are but I do think I remember that you cant use a Fluidampr. Again, not completely sure.....and I'm rambling on once more.
10-11-2015, 12:12 PM
#55
Registered User
FB meaning the Glacier "Fuel Boss". I'm not sure what to think about running a mechanical only system either. Maybe there's no reason for concern. You may find better answers from those who actually have the various mechanical systems. Try Googling all the mechanical fuel pumps and see what the most current threads have to say about them. I'd also call Glacier and ask personally.
10-11-2015, 07:53 PM
#58
Registered User
Thread Starter
ok so I've been doing some researching and I'm thinking of either going with the Raptor 150 or the FASS 150 adjustable. Im thinking that the 150gph is a good choice for me since I have the Smarty and the 75hp injectors. What do you think? It shouldn't hurt anything from what I've read. I have found possibly one drawback to each so far. The FASS, like you mentioned has the boost compensation. Which allows you to plumb your intake pressure to it so that it raises the pressure when the demand is greater. It sounds good in theory but Im not crazy about this idea, I don't need all that piping to run and possible leaks to have. Im planning to ask FASS if you can use the pump normally without it. My issue with Raptor is small and their pump is starting to look more and more attractive to me. I am just wondering if yours came with those silly quick connect fittings that i see it pictured with online or if it comes with normal push lock and JIC fittings? I don't want all those weird little quick connects in my fuel system. To me they are just more places to leak. Also, any recommendations on who to buy that Raptor from?
10-11-2015, 08:38 PM
#59
Registered User
The 150 should be fine. Lots of people run 150 pumps without issues. I'm not a fan of the boost compensation pump either. But that doesn't mean it doesn't work.
In regards to the Raptor, I would suggest staying away from Pureflowairdog products. A little history about Pureflowairdog..... FASS started this aftermarket fuel pump industry about a decade ago. Pureflow was a spin off from FASS through the result of a family/partnership split up. Pureflow and FASS built almost the same exact pumps and both companies built quality too but FASS pumps were recognized as model differences whereas Pureflow had names for theirs like Airdog and Raptor. After a few years or so Pureflow sold out to some unknown company and became Pureflowairdog. Thats when all the problems arose and no longer was the Airdog or Raptor a good pump to have. Over the past couple years or so there have been multiple threads about the problems with those pumps. LOTS of problems. Google problems with Airdog and you'll see what I mean. Forum members now just recommend FASS as their quality still remains.
That said, the Raptor 100 I have was from back when Pureflow was building quality pumps. If it ever gives me trouble then I'm not sure what I'll do. Maybe try rebuilding it if possible or converting over to a Fuel Boss. I'll cross that bridge if I get to it.
In regards to the Raptor, I would suggest staying away from Pureflowairdog products. A little history about Pureflowairdog..... FASS started this aftermarket fuel pump industry about a decade ago. Pureflow was a spin off from FASS through the result of a family/partnership split up. Pureflow and FASS built almost the same exact pumps and both companies built quality too but FASS pumps were recognized as model differences whereas Pureflow had names for theirs like Airdog and Raptor. After a few years or so Pureflow sold out to some unknown company and became Pureflowairdog. Thats when all the problems arose and no longer was the Airdog or Raptor a good pump to have. Over the past couple years or so there have been multiple threads about the problems with those pumps. LOTS of problems. Google problems with Airdog and you'll see what I mean. Forum members now just recommend FASS as their quality still remains.
That said, the Raptor 100 I have was from back when Pureflow was building quality pumps. If it ever gives me trouble then I'm not sure what I'll do. Maybe try rebuilding it if possible or converting over to a Fuel Boss. I'll cross that bridge if I get to it.
10-11-2015, 08:48 PM
#60
Registered User
Thread Starter
The 150 should be fine. Lots of people run 150 pumps without issues. I'm not a fan of the boost compensation pump either. But that doesn't mean it doesn't work.
In regards to the Raptor, I would suggest staying away from Pureflowairdog products. A little history about Pureflowairdog..... FASS started this aftermarket fuel pump industry about a decade ago. Pureflow was a spin off from FASS through the result of a family/partnership split up. Pureflow and FASS built almost the same exact pumps and both companies built quality too but FASS pumps were recognized as model differences whereas Pureflow had names for theirs like Airdog and Raptor. After a few years or so Pureflow sold out to some unknown company and became Pureflowairdog. Thats when all the problems arose and no longer was the Airdog or Raptor a good pump to have. Over the past couple years or so there have been multiple threads about the problems with those pumps. LOTS of problems. Google problems with Airdog and you'll see what I mean. Forum members now just recommend FASS as their quality still remains.
That said, the Raptor 100 I have was from back when Pureflow was building quality pumps. If it ever gives me trouble then I'm not sure what I'll do. Maybe try rebuilding it if possible or converting over to a Fuel Boss. I'll cross that bridge if I get to it.
In regards to the Raptor, I would suggest staying away from Pureflowairdog products. A little history about Pureflowairdog..... FASS started this aftermarket fuel pump industry about a decade ago. Pureflow was a spin off from FASS through the result of a family/partnership split up. Pureflow and FASS built almost the same exact pumps and both companies built quality too but FASS pumps were recognized as model differences whereas Pureflow had names for theirs like Airdog and Raptor. After a few years or so Pureflow sold out to some unknown company and became Pureflowairdog. Thats when all the problems arose and no longer was the Airdog or Raptor a good pump to have. Over the past couple years or so there have been multiple threads about the problems with those pumps. LOTS of problems. Google problems with Airdog and you'll see what I mean. Forum members now just recommend FASS as their quality still remains.
That said, the Raptor 100 I have was from back when Pureflow was building quality pumps. If it ever gives me trouble then I'm not sure what I'll do. Maybe try rebuilding it if possible or converting over to a Fuel Boss. I'll cross that bridge if I get to it.