Isspro fuel sender

[Red Rambler]

1 hour ago, 01cummins4ever said:

Personally, I would start with verifying fuel pressure with a test gauge and go from their, before replacing parts, 

Where would I hook up the test gauge. I don’t have a Schrader valve on the back on my filter. Is there an alternate test port location? I assume I could unscrew my sender and use that location to hook up a fuel pressure test gauge. 

Edited May 16, 2021 by Red Rambler

[LorenS]

32 minutes ago, Red Rambler said:

I could unscrew my sender and use that location to hook up a fuel pressure test gauge. 

Yes.

[Mopar1973Man]

Hence why my set up is on the fender for this exact reason...

 

 

Now I can unscrew the fuel pressure sender add a tee and hook up my test gauge and my sender back and then go for ride and test the a-pillar gauge in real time without the fuss or mess. 

 

 

I've even got all the fitting for any system I've got to tie into...

 

As for my protection its... 

 

Tap point in-between the VP44 and the stock fuel filter. Needle valve for emergency shut down of fuel in this plumbing then a snubber. I used PTC (push to connect) fittings. Then 5 feet of 1/8 inch air brake line the over to my relocation bracket and sensor is last. After the needle valve you'll see a brass fitting that is the snubber (sinstered metal).

 

 

Edited May 16, 2021 by Mopar1973Man

[Red Rambler]

I ordered the vpmax test gauge kit from vulcan. So will do some testing once it shows up. Thanks all for input so far. 

Has anybody rigged up a permanent test spot that could be used. Basically hook the test gauge up as needed. I was thinking of getting a tapped banjo bolt to use at the VP inlet and put a needle valve on the end of the banjo that could be opened and closed as needed. Use that needle valve to hook my test gauge up to. 

Edited May 16, 2021 by Red Rambler

[Dieselfuture]

There were a few people that had some issues with something on return side of mechanical pumps that made pressure fluctuate, kinda like ball and spring set up on electrical pumps 

[Red Rambler]

3 minutes ago, Dieselfuture said:

There were a few people that had some issues with something on return side of mechanical pumps that made pressure fluctuate, kinda like ball and spring set up on electrical pumps 

Yeah, that’s the check valve. It has a piston valve that is spring actuated. It can get debris lodged in the piston or spring and not allow the valve to open and close properly lowering fuel pressure. But I have cleaned mine twice and no debris. 

[Silverwolf2691]

@Red Rambler, I have the GDP Fuel Boss as well, hooked up all mechanical. With the check valve/fuel pressure regulator that they sent me I was barely pushing 14 PSI driving down the road. I had to nearly tach out the rpms if I wanted much more in terms of PSI. I have since replaced the check valve/regulator a few years ago now with an actual fuel pressure regulator from fuelab. I have it set a bit higher than I should at 22 PSI, but it never moves from there unless the fuel is low (1/8 tank or less) and after being run for a while, so warmed up fuel being thinner. Only other time is when its really cold, my gauges start reading a couple psi higher than usual. (Southern New England winter, 5° above in the daytime/-10° at night is a deep freeze for us).

 

I never liked the brass check valve because that's what it is, a check valve. Granted add a bit of preload to the spring and it wont open right away but its not designed as such and I think that's why we get fluctuations and what not from that set up. Spring design isn't correct for relief service and/or force balances/area shift are out of whack with the poppet.

 

I work at a company that specializes in microhydraulics (smallest insert in my group is Ø.187 OD and more stuff goes inside) and our pressure relief and check valve divisions are different, partly from order volume vs cnc machines, but also because the math for the different designs is somewhat different. 

[Red Rambler]

8 minutes ago, Silverwolf2691 said:

@Red Rambler, I have the GDP Fuel Boss as well, hooked up all mechanical. With the check valve/fuel pressure regulator that they sent me I was barely pushing 14 PSI driving down the road. I had to nearly tach out the rpms if I wanted much more in terms of PSI. I have since replaced the check valve/regulator a few years ago now with an actual fuel pressure regulator from fuelab. I have it set a bit higher than I should at 22 PSI, but it never moves from there unless the fuel is low (1/8 tank or less) and after being run for a while, so warmed up fuel being thinner. Only other time is when its really cold, my gauges start reading a couple psi higher than usual. (Southern New England winter, 5° above in the daytime/-10° at night is a deep freeze for us).

 

I never liked the brass check valve because that's what it is, a check valve. Granted add a bit of preload to the spring and it wont open right away but its not designed as such and I think that's why we get fluctuations and what not from that set up. Spring design isn't correct for relief service and/or force balances/area shift are out of whack with the poppet.

 

I work at a company that specializes in microhydraulics (smallest insert in my group is Ø.187 OD and more stuff goes inside) and our pressure relief and check valve divisions are different, partly from order volume vs cnc machines, but also because the math for the different designs is somewhat different. 

Thanks @Silverwolf2691, after looking at my check valve a bit more, it has the tiniest of grooves in it from where it has come off the seat and then back on, multiple cycles obviously. However, it isnt enough of a groove to catch my finger nail. If I get a low reading on my new test gauge also, meaning its not likely my sender I will look into the fuel pressure regulator you mention, that might be the better setup versus the check valve. If my check valve is allowing the slightest of fuel pass when its not supposed to, could be the main issue obviously. I have added more shims to my check valve to try and make the spring stiffer with no change to my issues. 

[Silverwolf2691]

51506 Custom Fuel Pressure Regulator (fuelab.com) (was supposed to be a link)

 

Just incase you continue down this route, I believe this is the part number that I got, except I got mine through summit I think. I can double check when I get home.

Fair warning, moderately expensive.. 

I think it will be a bit easier to order on summit than their new website.. Really confusing on how to select your options for a "custom" regulator from them.

 

Just need the 10-25 psi range. 

Edited May 18, 2021 by Silverwolf2691

[Red Rambler]

I received my test gauge from Vulcan on Saturday, and immediately did some testing. My sender does not appear to be the issue as the test gauge was showing low pressure as well, 14 PSI. My thought was to buy a new check valve as one part in my check valve has a small wear groove in it, the poppet. Unsure if it is causing the issues at this point, but worth replacing. The check valve on Glacier Diesel's website is right at $70. I did some digging and was able to find what I hope is the exact replacement check valve for a cheaper price. Through my research, it appears the check valve is an Enderle check valve, unsure if Enderle is the brand name or not. The check valve I purchased is 6AN, and comes with the springs for 17psi. In the check valve, it appears there is only two wear items, the spring and the poppet. The website I found these parts on looks like a drag racing website on the west coast, good vibes racing. I have already received tracking for my order. I purchased both a new check valve, and a new poppet. Once these show up, should be a 5 minute deal to swap these out. I also see an aluminum bodied check valve, and it has a stainless steel poppet. In this instance Im not sure if the brass body or the aluminum body would be better. Both brass and aluminum are softer than the SS poppet. Currently I dont see any wear on the Brass body insides, just the poppet itself. 

 

http://www.goodvibesracing.com/check_valves_&_components.htm

 

 

Edited May 24, 2021 by Red Rambler

[IBMobile]

  I started loosing fuel pressure at idle over a couple of years 17PSI and now down to 8 PSI.  18-19 PSI at  2000 RPM and drops to 16 PSI under load.  I checked the "fuel pressure regulator"  saw no problem; I've blown out the fuel lines with compressed air then tried clamping off the fuel return lines with no increase in pressure.  

[Red Rambler]

6 minutes ago, IBMobile said:

  I started loosing fuel pressure at idle over a couple of years 17PSI and now down to 8 PSI.  18-19 PSI at  2000 RPM and drops to 16 PSI under load.  I checked the "fuel pressure regulator"  saw no problem; I've blown out the fuel lines with compressed air then tried clamping off the fuel return lines with no increase in pressure.  

My struggle is the dropping pressure under load which is new to me. Normally, upon acceleration the fuel pressure would rise, but lately, it goes down if I do a WOT run. In my mind, the only viable reason is the check valve is allowing fuel to bypass, thus lowering pressure. If my new check valve corrects the issue than the check valve is a wear item and I might proceed as silverwolf has and get a true fuel regulator lined out. @IBMobile are you still running the stock brass check valve? 

[IBMobile]

2 hours ago, Red Rambler said:

are you still running the stock brass check valve? 

Yes

[01cummins4ever]

@Red Ramblerglad you saved yourself from replacing the fuel pressure sender unnecessarily, Although 14 psi. at idle  is nothing to be alarmed about the declining fuel pressure on acceleration is, Your bypass valve could be the culprit but for a rude test you could try to clamp off the line before the bypass valve or simply give the valve a few love taps with a wrench of something and see if your fuel pressure jumps any, 

 

Do you run a pre filter/strainer in line before the pump?  

[Dieselfuture]

Could it be a faulty return banjo bolt on vp? I don't think they go out that much, at least I haven't heard much on that, maybe worth checking though. If junk can get in to check valve on the pump maybe some of it made it to that return banjo. Up on installation of any fuel system it's important to purge all the lines before connecting it all. Just a thought.

[Red Rambler]

1 hour ago, 01cummins4ever said:

@Red Ramblerglad you saved yourself from replacing the fuel pressure sender unnecessarily, Although 14 psi. at idle  is nothing to be alarmed about the declining fuel pressure on acceleration is, Your bypass valve could be the culprit but for a rude test you could try to clamp off the line before the bypass valve or simply give the valve a few love taps with a wrench of something and see if your fuel pressure jumps any, 

 

Do you run a pre filter/strainer in line before the pump?  

Same, I don’t like getting nickel and dimed to death, but it’s a necessary evil at times. I have taken my check valve apart a few times and it appears to be working as it should, but does have the tiny wear groove, IMO not enough to cause my return valve to open, but if it allows fuel to pass by in some fashion it could be the issue. I don’t run any strainer or pre filter before my pump. I run a strainer on my return line(post pump) that was replaced when I replaced my VP. Which was roughly two fuel tanks ago. I will get my son to watch fuel pressure and pinch the return line. I haven’t done that yet. 

1 hour ago, Dieselfuture said:

Could it be a faulty return banjo bolt on vp? I don't think they go out that much, at least I haven't heard much on that, maybe worth checking though. If junk can get in to check valve on the pump maybe some of it made it to that return banjo. Up on installation of any fuel system it's important to purge all the lines before connecting it all. Just a thought.

I guess I don’t see why it couldn’t be junk/blockage anywhere in the system. For sure possible. If my new check valve doesn’t solve the mystery than it would be a free option to check all my line connections/fittings. Blow them out with compressed air. I did put a new sending unit in as well, twice, so possibly some gunk moved around at that time, even though the inside of my tank looked really clean. 

Edited May 25, 2021 by Red Rambler

[Red Rambler]

Still waiting on my parts, usps is killing me lately...

[Mopar1973Man]

USPS can be slow yet being the amount of freight still being sent making up from the COVID-19 shut down.

[Red Rambler]

New check valve. Same results. Fuel pressure dropping upon acceleration which isn’t normal. Not sure about my next steps in trouble shooting. Need to get in touch with rich at glacier diesel, see if my pump is able to be cleaned or taken apart to ensure it isn’t pump related.  Other thing I thought of is to unplug the Hobbs switch and see if that changes anything. Not sure a bad Hobbs switch can cause the stock lift pump to activate in some fashion. 
 

Edited June 3, 2021 by Red Rambler

[01cummins4ever]

Not quite sure on the Hobbs switch but I can see the potential for issues, I think @IBMobileruns that set up and keeps it deactivated, He can probably fill you in on that,

 

I just run straight mechanical, and an old school draw straw in the tank outside the basket and no needle valve, just a snubber, fuel pressure jumps to 16 the second engine fires, been going strong for several years