The lift pump is cheap enough, it might be worth a try just swapping it out. You still have the stock style diaphragm lift pump, right?
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I agree with Johnny, diaphragm pump is looking for excuses to fail. If you plan to replace, spend $40 more and get a low pressure piston pump. I strongly suggest a low pressure fuel pressure gauge at this point too. VE pumps are lubed with diesel fuel and they are sucking fuel through a faulty diaphragm pump(which they will) they will burn up. I don't know how old your diaphragm pump is, but a good indicator that it's leaking can sometimes be felt in the priming lever when the pump is against the lobe of the cam. Another indicator is the engine struggling to start, does it take longer to fire? If so the VE pump is doing all the work to get fuel through the filters and through the weak pump to pressurize the injectors. Food for thought.
- Thread starter
- #2,144
Good job guys. It looks like it's the lift pump. Borrowed a temporary gauge for a testing session and I was barely getting 4psi at idle and it only got worst when I'd rev the engine.
We suspect with the previous adjustment of the full power screw coupled with bad fuel that was clogging my fuel filters a restriction and backpressure was created that damaged the diaphragm pump so that it could not keep up to the demand for more fuel from the VE trying to make more boost.
Went through and checked other stuff and made some adjustments to some of the intake tube connections to create better seals just for good measure.
Now I'm hunting for a piston style lift pump. There are basically three options I'm looking into.
1. Get a low pressure piston lift pump
2. Get a high pressure piston lift pump from a 2nd gen and use a regulator to bring the pressure down to VE injection pump tolerances. Generally no more than 15psi. This will be more work to install a regulator.
3. Get a high pressure piston lift pump from a 2nd gen and get a new spring from thehungrydiesel.com to install that will reduce the pressure output of the lift pump. This would be easier but the spring is not cheap.
The benefit of choosing either 2 or 3 is that the high pressure lift pump has a bigger internal piston and will supply more volume to the VE. It sounds like this should be able to supply enough fuel to my IP to support my goal of 50psi of boost. Prices are all over the board so I'm looking at my options.
We suspect with the previous adjustment of the full power screw coupled with bad fuel that was clogging my fuel filters a restriction and backpressure was created that damaged the diaphragm pump so that it could not keep up to the demand for more fuel from the VE trying to make more boost.
Went through and checked other stuff and made some adjustments to some of the intake tube connections to create better seals just for good measure.
Now I'm hunting for a piston style lift pump. There are basically three options I'm looking into.
1. Get a low pressure piston lift pump
2. Get a high pressure piston lift pump from a 2nd gen and use a regulator to bring the pressure down to VE injection pump tolerances. Generally no more than 15psi. This will be more work to install a regulator.
3. Get a high pressure piston lift pump from a 2nd gen and get a new spring from thehungrydiesel.com to install that will reduce the pressure output of the lift pump. This would be easier but the spring is not cheap.
The benefit of choosing either 2 or 3 is that the high pressure lift pump has a bigger internal piston and will supply more volume to the VE. It sounds like this should be able to supply enough fuel to my IP to support my goal of 50psi of boost. Prices are all over the board so I'm looking at my options.
First and foremost, I would not drive this truck, or even turn it on, until you get that lift pump replaced. Based on the reading I've done, when the IP is sucking its own fuel is when it burns up the quickest.
I've been shopping for a piston lift pump as well. It's either option 1 or 3 to me. I don't like the idea of an inline pressure regulator when the pressure line is such a straight shot from the pump to the filter head. On top of that, if the regulator fails, and it feeds 100% of line pressure to the IP, then you'll have a crankcase full of diesel super quick.
Either way, I'm glad you found the problem
I've been shopping for a piston lift pump as well. It's either option 1 or 3 to me. I don't like the idea of an inline pressure regulator when the pressure line is such a straight shot from the pump to the filter head. On top of that, if the regulator fails, and it feeds 100% of line pressure to the IP, then you'll have a crankcase full of diesel super quick.
Either way, I'm glad you found the problem
It was on my santa wish list, so give me a day and we'll find out! Otherwise, I'll have one by next week.
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- #2,148
I decided to go with option 3 from my previous post. I found a new genuine Cummins pump on ebay for a good price and placed the order. Tracking shows it will be here on Friday but I'm not counting on it with Santa disrupting flight patterns this week. I also ordered a replacement spring to reduce the pressure of the piston lift pump from the hungry diesel and tracking shows it will also show up on Friday. I chose the 15psi spring since I've got big injectors (for a VE pumped 4bt anyways) from here: http://thehungrydiesel.com/Low-Pressure-Lift-Pump-Spring-Low-Pressure-Lift-Pump-Spring.htm
The engine starts great it doesn't struggle, there's no "extra" oil on the dipstick, but the truck has been parked for the time being.
The engine starts great it doesn't struggle, there's no "extra" oil on the dipstick, but the truck has been parked for the time being.
Is the pressure line that goes from the piston lift pump to the filter head different than the diaphragm pump?
Waiting to see how you like this setup. If you like it, I'll copy you (again).
Thanks Mike and Merry Christmas!!
- Thread starter
- #2,150
From what I've read the fitting should be the same to connect up the current hard line to the piston pump but that the hard line may need to be massaged to fit the new angle. I'll definitely be finding out. The piston pump also needs a spacer plate and I've found 3/16" as a repeated thickness reference. I'm planning to shape one out of metal I have. I anticipate that the dimensions of the piston pump will conflict with where I have my oil catch can for the crankcase breather so I'll probably need to move that down a tad. From my prefilter to the lift pump I have 5/16" fuel line. I plan to step that up to 3/8" or 1/2" which means I'll need to get some more fuel line and the right fittings for the outlet of the prefilter and the inlet of the piston pump.
i'l be very curious to see how the twins tuning goes. I am chasing boost and fuel tuning myself. running SAC 5x12 and more haze/smoke than i like using an hx30 picking up an hx35w to see how it does for me but like have experienced i am sure the low end boost will be poor and lots of smoke. ill probably be heading to twins like you. thinking about picking up some 5x12 VCO to try. your 5x14 seems big to me for mild 200 hp that is my goal too. i have not rebuilt the head, put studs in, or springs. will start with an over torque and springs and go from there.
i'm in the 25-28psi range and am choking my turbo out as i am quicky building there and egt's climb with no more boost. a waist gate should help with a bit more boost but still looking for more.
also a great tread. saw the twins last week and thought i should read the thread and before commenting and asking questions. not many questions after reading all your details and posts. I give you props for going back a re-linking your pictures. i gave up after webshots double crossed.
i'm in the 25-28psi range and am choking my turbo out as i am quicky building there and egt's climb with no more boost. a waist gate should help with a bit more boost but still looking for more.
also a great tread. saw the twins last week and thought i should read the thread and before commenting and asking questions. not many questions after reading all your details and posts. I give you props for going back a re-linking your pictures. i gave up after webshots double crossed.
- Thread starter
- #2,153
Did you happen to get my PM reply? I had dimensions in there for you.
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- Thread starter
- #2,154
Thanks for reading up and yes the photo re-linking has been the worst part.
I'm probably looking at 250+ now, maybe close to 300. I definitely have the fueling potential now I just need to get the tuning dialed in; I think there is a lot in tuning. It seems a little tricky trying to get big sticks to run clean but I'll keep playing with the tuning until I can find that sweet spot. That will probably be a puff of black but hopefully cleaned up quickly. I would think 5x12s would be a great performance size but since I've got the 5x14s already I'll play with these to see what they can do. These little engines are just too much fun with more boost.
maybe a dumb question...but what is gained in running a dual turbo setup on a street/offroad 4wd?... I know or realize a dual turbo can put out more power..but really whats the advantage of a dual turbo setup vs a single? Is it more of a best of both worlds...spreads the power across the rpm range better? or maximizes the available power .. Just wondering, as it applies to the 4wd world?
Was wondering about the complexity of the plumbing and setup too...value added?
Not throwing rocks..just wondering. I realize that many folks do things for the fun factor etc..or to see what can be explored. Just wondering if the dual turbo setup opens up another world of power...that can be tailored toward bottom end power (torque).
Was wondering about the complexity of the plumbing and setup too...value added?
Not throwing rocks..just wondering. I realize that many folks do things for the fun factor etc..or to see what can be explored. Just wondering if the dual turbo setup opens up another world of power...that can be tailored toward bottom end power (torque).
Twins will have little to no added benefit over a single for offroading.
However, twins on the street allows you to have more total boost with boost coming on earlier, and most importantly more flow, throughout the entire RPM range. This translates to much higher overall power.
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- Thread starter
- #2,157
Not a dumb question. I'll expand more of what Johnny is saying. First off (just for info's sake) there are three different kinds of "twin" turbo setups:
Parallel - good example is for a V shaped engine where a turbo is placed on each side. The turbos are spec'd the same.
Sequential - a small turbo and a big turbo. Exhaust feeds the small and spools it first providing boost for the engine; exhaust then flows into the big turbo. Once the big turbo spools up the exhaust from the small gets diverted all to the big turbo. So only one turbo is technically doing the work/providing the boost.
Compounds - a small turbo and a big turbo. These turbos work together/share the load to make boost with the small turbo compounding the boost coming in from the big. Because of the massive boost numbers that can be achieved through compounding this configuration is mostly used on diesels which can typically hold more boost.
What I've done is a Compound set up. The reason why this rules in the diesel world is because you can have your cake and eat it too. With the turbos sharing the load, neither are worked as hard as they would be run as singles. Proper tuning can place both turbos at their best efficiency on their maps which means the boost they are making is cool, dense boost. This means more power at lower EGT temps than what a single could do. This is one reason compounds are great for towing. If you're not towing it allows you to built more power. With more power you don't have to keep your foot on the accelerator as long to get up to speed. With more efficient power some see mileage improvements. Since the two turbos in compounds are working together a properly set up system can quickly build boost at lower rpms, continue making power at higher rpms and keep the EGT's down. You get the best of both worlds in small and big turbo performance.
For offroading, it depends what kind of offroading you do. If it's low rpm, low speed stuff then really any turbo whether single or twins isn't really doing much. If it's mud-slinging mayhem, then twins will benefit by getting more power with a broader range and keeping things cooler. For the average mix a small turbo helps out the most in offroad. So a small single or a compound set up will preform about the same; however since compounds are more efficient at making boost, I think they excel a little more than a single by making a broader range of power. Compounds overall improve drivability.
As with anything, if it's properly set up and supported a twin set up can be just as reliable as singles. I find it interesting that a whole bunch of OEMs are putting turbos on a bunch of their models, meaning it's becoming more common. I'm seeing quite a bit more twin setups coming out of the factory as well. This is one of the technologies that isn't new but is allowing engines nowadays to continue to make more power but be more efficient.
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Ok, just a little insight sough here.. So knowing what you know now and looking back to where you started 7 plus years ago, is what you wanted what you now have or are trying to achieve or did you not know what you really wanted or has what you wanted just metamorphosed into what you are now trying to achieve?
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- #2,159
Kief, I am plagued with the disease known as tinkeritis. I cannot leave well enough alone so I continually strive for something better.
I think I still want the best all a round rig I can get which is mostly related to what I started out wanting. I don't think I'm there yet and I don't believe there is only one formula that will satisfy that. I think I've come a long way from the stock FJ60 I started with and that I'm achieving some of my goals but I doubt I'll ever get all of them perfect. It is somewhat unrealistic to want one vehicle to do everything but that doesn't stop me from pushing my envelope and seeing what I can come up with or digging up what other's have done and apply it. Of course that takes time and money along with having to factor in family, life and dreams. I do have a dissatisfaction with my rig but without that I'd never strive for more so I think for me it's healthy. Instead of doing this across several rigs I'm just doing it with one. Would I have been better off setting up a wheeler and tow rig, maybe, but then I'd always wonder if one rig could do the same thing. I guess this is the poison I've chosen so I'm seeing what I can do with it and I believe what I want out of it can change as I change throughout my life. It will be interesting for me to see what my vehicular tastes are in another 10 years.
One thing's for sure, this vehicle is a means to gain experiences and memories hopefully shared with the ones dear to me. I can't wait to hear of the stories my children will tell when they remember the family outings in Daddy's truck. There is still so much more to see.
I think I still want the best all a round rig I can get which is mostly related to what I started out wanting. I don't think I'm there yet and I don't believe there is only one formula that will satisfy that. I think I've come a long way from the stock FJ60 I started with and that I'm achieving some of my goals but I doubt I'll ever get all of them perfect. It is somewhat unrealistic to want one vehicle to do everything but that doesn't stop me from pushing my envelope and seeing what I can come up with or digging up what other's have done and apply it. Of course that takes time and money along with having to factor in family, life and dreams. I do have a dissatisfaction with my rig but without that I'd never strive for more so I think for me it's healthy. Instead of doing this across several rigs I'm just doing it with one. Would I have been better off setting up a wheeler and tow rig, maybe, but then I'd always wonder if one rig could do the same thing. I guess this is the poison I've chosen so I'm seeing what I can do with it and I believe what I want out of it can change as I change throughout my life. It will be interesting for me to see what my vehicular tastes are in another 10 years.
One thing's for sure, this vehicle is a means to gain experiences and memories hopefully shared with the ones dear to me. I can't wait to hear of the stories my children will tell when they remember the family outings in Daddy's truck. There is still so much more to see.
- Thread starter
- #2,160
To be able to get more boost I needed more fuel and the diaphragm lift pump wasn't going to cut it. I read somewhere that suggested the diaphragm style lift pump (if it's healthy) was OK at supplying fuel to the VE to reach mid to upper 30s in boost. Since my target boost with the twins is higher it was time to upgrade.
This is the old.
Here is the new. I found this on ebay for a pretty good price. It is a genuine cummins part and it came with two gaskets. It was in a sealed bag and the pump had been lubricated before it was put in the bag. You can kind of see the two plugs that are in the inlet and outlet. They were label with the hole size which I thought was a nice touch. The inlet is 1/2" npt and the outlet is 14x1.5mm
Close up of the part number 4988747. This is for a 2nd gen 5.9 cummins and is a high pressure pump.
The same day my replacement spring from thehungrydiesel.com showed up and it was very simple to swap out. The new spring did not have the rate of the old spring. You can see that the original (the black spring) has thicker wire gauge than the replacement (the silver spring). Again I chose a 15psi spring considering the boost I wanted to push with the big injectors I'm running.
Using one of the included gaskets as a template I cut out a spacer from 3/16" plate I have.
Here's the new pump with a 3/8" hose barb converted from 1/2" npt on the inlet. I reused my old pump's bolts and have the spacer plate I made with gaskets mocked up in this pic. I test fit the pump without the gaskets at first to see how it fit. As suspected my crankcase breather catch-can needed to be moved for this pump to fit so I took it off for the time being until I adjust the mounting bracket down. With the pump in place I was able to see how the hardline from the pump outlet to the main filter would fit.
I upsized the fuel line from my pre-filter to this pump to 3/8". My pre-filter pump head was also 1/2" npt so I picked up two of those hose barbs to make it work. I was looking for SAE J30 R9 hose but I was able to find some compatible fuel line at a local auto parts place. In case I run biodiesel I wanted the hoses rated for it and all my other fuel lines are rated for bio.
My original hardline from the lift pump to the main filter physically fit but needed to be reshaped. I played with bending it but in the end I cut it and used the ends for the fittings. I replaced the center section with 5/16" fuel line and that gave me the flexibility I wanted. At some point I may redo this section with some ~AN fittings but for now this works fine. It will be an easy place to put a fuel pressure gauge as well. Since I'll see a max of 15psi on this line simple hose clamps have been happily keeping it sealed.
I also opened up the holes on the banjo bolt to 11/64 for a little more flow potential.
Piston pump installed. A little hard to see the hardline that I turned into a soft line but it's there.
Results:
I have not hooked up a fuel pressure gauge yet but just by installing the new lift pump I gained about 40-50 rpm on idle. Without changing any fuel settings I took it around the block but it was still low on power and boost. The last thing I did not try was to bypass my MBC. Once I got that bypassed I was back in business and I noticed it was stronger on the upper rpm range as well. I replaced the new stiffer spring I had put in the MBC with the softer one I started with and boost could be built again and power was up. So while the MBC was causing a fueling issue because its spring was too stiff and requiring too much boost to overcome its setting thus causing the AFC to not add more fuel as boost rose, the new piston pump with more pressure and volume is going to better support the boost that I'm after and keep the VE supplied to keep it healthy.
With my fueling cleared up I continued with more tuning. I added a full turn in on the full power screw and took it for a spin. Now I was hitting some kind of wall with the total boost gauge. It would increase up to 30psi and then stop. The gauge would also hang when I let off the throttle and then decrease abruptly. I dug back into it by removing the signal line at both ends and blowing it out with high pressure air from the shop compressor. I then regulated the supply to 60psi to test the gauge holding a rubber tipped nozzle to the gauge inlet to create a seal. I go the gauge to operate correctly and decided to hook it all back up. There must have been something in the line because it's now working fine.
For my latest tuning adjustments I left the full power screw as it was, 1/4 up on the starwheel, 1/4 up on the smoke screw, bumped timing to 18 degrees, and played with a couple different springs on my springgate. I was surprised at how stiff the spring needs to be to get the PR ratios I'm looking for. I got some more springs to play with and ditched the dual rate idea. So far I'm at a .080 WG 1.75" long spring
So with my latest tune here are my results: I'm seeing a total boost of 45psi with 21psi coming from the primary.
Total psi 45 = total PR 4.06
Primary psi 21 = primary PR 2.43
Secondary PR 1.67 = Sec psi 9.9
~10 psi total at cruising (~65mph) with EGTs at 750F. On my WOT assaults to see 45psi I barely touched 1000F. I think this will climb a little more on highway grades. Making the secondary do a little more work has brought the EGTs down some along with the timing bump. And it's cleaning up to a reasonable haze. I'm much closer than I was two weeks ago but I've got a little bit more to go. I might drive it for a week or two at this tune to see how it sits.
This is the old.
Here is the new. I found this on ebay for a pretty good price. It is a genuine cummins part and it came with two gaskets. It was in a sealed bag and the pump had been lubricated before it was put in the bag. You can kind of see the two plugs that are in the inlet and outlet. They were label with the hole size which I thought was a nice touch. The inlet is 1/2" npt and the outlet is 14x1.5mm
Close up of the part number 4988747. This is for a 2nd gen 5.9 cummins and is a high pressure pump.
The same day my replacement spring from thehungrydiesel.com showed up and it was very simple to swap out. The new spring did not have the rate of the old spring. You can see that the original (the black spring) has thicker wire gauge than the replacement (the silver spring). Again I chose a 15psi spring considering the boost I wanted to push with the big injectors I'm running.
Using one of the included gaskets as a template I cut out a spacer from 3/16" plate I have.
Here's the new pump with a 3/8" hose barb converted from 1/2" npt on the inlet. I reused my old pump's bolts and have the spacer plate I made with gaskets mocked up in this pic. I test fit the pump without the gaskets at first to see how it fit. As suspected my crankcase breather catch-can needed to be moved for this pump to fit so I took it off for the time being until I adjust the mounting bracket down. With the pump in place I was able to see how the hardline from the pump outlet to the main filter would fit.
I upsized the fuel line from my pre-filter to this pump to 3/8". My pre-filter pump head was also 1/2" npt so I picked up two of those hose barbs to make it work. I was looking for SAE J30 R9 hose but I was able to find some compatible fuel line at a local auto parts place. In case I run biodiesel I wanted the hoses rated for it and all my other fuel lines are rated for bio.
My original hardline from the lift pump to the main filter physically fit but needed to be reshaped. I played with bending it but in the end I cut it and used the ends for the fittings. I replaced the center section with 5/16" fuel line and that gave me the flexibility I wanted. At some point I may redo this section with some ~AN fittings but for now this works fine. It will be an easy place to put a fuel pressure gauge as well. Since I'll see a max of 15psi on this line simple hose clamps have been happily keeping it sealed.
I also opened up the holes on the banjo bolt to 11/64 for a little more flow potential.
Piston pump installed. A little hard to see the hardline that I turned into a soft line but it's there.
Results:
I have not hooked up a fuel pressure gauge yet but just by installing the new lift pump I gained about 40-50 rpm on idle. Without changing any fuel settings I took it around the block but it was still low on power and boost. The last thing I did not try was to bypass my MBC. Once I got that bypassed I was back in business and I noticed it was stronger on the upper rpm range as well. I replaced the new stiffer spring I had put in the MBC with the softer one I started with and boost could be built again and power was up. So while the MBC was causing a fueling issue because its spring was too stiff and requiring too much boost to overcome its setting thus causing the AFC to not add more fuel as boost rose, the new piston pump with more pressure and volume is going to better support the boost that I'm after and keep the VE supplied to keep it healthy.
With my fueling cleared up I continued with more tuning. I added a full turn in on the full power screw and took it for a spin. Now I was hitting some kind of wall with the total boost gauge. It would increase up to 30psi and then stop. The gauge would also hang when I let off the throttle and then decrease abruptly. I dug back into it by removing the signal line at both ends and blowing it out with high pressure air from the shop compressor. I then regulated the supply to 60psi to test the gauge holding a rubber tipped nozzle to the gauge inlet to create a seal. I go the gauge to operate correctly and decided to hook it all back up. There must have been something in the line because it's now working fine.
For my latest tuning adjustments I left the full power screw as it was, 1/4 up on the starwheel, 1/4 up on the smoke screw, bumped timing to 18 degrees, and played with a couple different springs on my springgate. I was surprised at how stiff the spring needs to be to get the PR ratios I'm looking for. I got some more springs to play with and ditched the dual rate idea. So far I'm at a .080 WG 1.75" long spring
So with my latest tune here are my results: I'm seeing a total boost of 45psi with 21psi coming from the primary.
Total psi 45 = total PR 4.06
Primary psi 21 = primary PR 2.43
Secondary PR 1.67 = Sec psi 9.9
~10 psi total at cruising (~65mph) with EGTs at 750F. On my WOT assaults to see 45psi I barely touched 1000F. I think this will climb a little more on highway grades. Making the secondary do a little more work has brought the EGTs down some along with the timing bump. And it's cleaning up to a reasonable haze. I'm much closer than I was two weeks ago but I've got a little bit more to go. I might drive it for a week or two at this tune to see how it sits.
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