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General Information => Upgrades (non engine related ) => Topic started by: theman53 on August 03, 2011, 09:57:50 am
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I am and always have been having problems with EGT. I stopped at a cummins shop yesterday and he couldn't believe I wasn't running a lift pump. He said in the truck world you can't make power without one on the VE pump. I explained they didn't take much fuel and he said it doesn't matter. That if you mash it at idle you loose all the advance until the pump picks up enough fuel to make up for what you have lost when punching it. He can show this under load with a timing light attachment. This is exactly the situation I have as it doesn't have snap off the bottom but when the pump is pulling good it does fine. I guess for those running a lift pump and others who know what is a good pressure to run these at? He said the 6B needs around 14psi to do the job all the time. What do you think we need?
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I have run a low pressure lift pump for a long time( about 5-7 PSI) and have always been happy.
not only does it help with performance, but it will keep you from getting air leaks as often.
-Owen
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I am and always have been having problems with EGT. I stopped at a cummins shop yesterday and he couldn't believe I wasn't running a lift pump. He said in the truck world you can't make power without one on the VE pump. I explained they didn't take much fuel and he said it doesn't matter. That if you mash it at idle you loose all the advance until the pump picks up enough fuel to make up for what you have lost when punching it. He can show this under load with a timing light attachment. This is exactly the situation I have as it doesn't have snap off the bottom but when the pump is pulling good it does fine. I guess for those running a lift pump and others who know what is a good pressure to run these at? He said the 6B needs around 14psi to do the job all the time. What do you think we need?
i bet we could do just fine with 5-10 psi of pressure at the pump inlet.. these things dont flow much fuel thru the pump.. it takes like 5-6 minutes to get a quart out of the return line at idle..
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Which is why I think if we had more flow to the pump we could have more pressure or more going through the return. At least it would be there if we needed it. I am unsure if it will work, but I will try it and see sometime. I am thinking if a holley blue pump is diesel rated I will see what 9psi will do.
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they make a green shaker pump thats diesel rated, and puts out about 6-8 psi without a regulator..
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How about a yamaha bike fuel pump? Any one off an FZR would do.
Nice compact unit that sits at 4 psi.
But I don't believe that it'll make any difference, the standard vane pump could flow a large volume of fuel, the amount of fuel injected as you 'mash the throttle' is so small in comparison that the pressure drop would be miniscule/ neglible.
Providing the vane pump is working properly.
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If I understand correctly the VE pump is about as opposite from the CIS injection system as can be. Our VE ramps up timing as the internal pressure rises. The vane pump is the only thing pulling fuel so when you do mash it from idle even if the pressure stayed the same as the engine RPM increased you wouldn't gain timing. Therefore you would lose response. I am thinking of putting about 14psi to it and change nothing else. See what happens, the worst I think that could happen is all the fuel would go through the out bolt back to the tank and I would be thinner in the wallet :D
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its still going to inject the same amount of fuel.. the regulator inside the pump isnt going to be letting any more fuel flow to the pump head than what it has now.. if it does, the governor will take care of it and bring it back to where it should be..
tyler pressure fed one of these pumps with pretty high pressure, and the advance curve DID NOT CHANGE.. that tells me that its not going to help any..
cummins VE pumps have like 7/16ths supply line to them, and still need a lift pump.. they MOVE ALOT MORE FUEL.. and use alot more fuel..
our engines move almost no fuel, and burn even less of it..
on my engine, i only noticed an improvement because my pump was shot. and it made it super easy to start.. i was more fond of the primer function, rather than anything else..
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actually giles has said before it will increase the fueling to a certain point, he didn't say how much. i was just reading daves 19 page franken thread haha, gotta read over that once in a while
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having taken a cummins VE pump apart, I can tell you that the vane pump in one of them is exactly the same as the one in the VW pump.
they will move the same amount of fuel as the VW VE pump.
it has more to do with the fact that the fuel system up to the pump is functioning under vacuum(for lack of a better word) and everything from the tank to the pump is a restriction(filter, hoses, water separators) by feeding the pump pressure, you are assuring that it is not starving for fuel, especially at higher throttle/RPM.
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I know it won't change the curve, but it won't let it fall.
EX: say pump pulls 6psi worth of fuel, you stab it and it either stays at 6psi or goes down to 3psi. Then you don't see any advance until the pump is spinning 2,000rpm and pulling it back up to 6psi then it starts advancing and then making more power. If you have the inline pump pushing the 6psi you stab it it never goes below 6 psi and the advance starts right away. The numbers maybe way off as I think the internal pump pressure at idle should be 43psi or something. But the difference between the 2 sides of the pump gives the advance. If the suction side falls or stays static at all my THEORY is that it will give me the problems I am having. ALSO, I think if I had a lighter car like MK1 rabbit and or a taller ring and pinion my issue wouldn't be as noticable. With my 3.67 R&P and the MK2 jetta I think the extra to get going and up in the RPM range is making what I have going on worse.
I am also going to run 3/8" line from the tank up to make sure that I don't have any flow restriction. Like I said, it will either work or send it all back through the out bolt and make no difference at all.
This is my theory and I think my EGT situation and gutless off idle is because of this. I want to put more fuel to it to get it to move and it does after it gets moving, but under 1,500 it is useless. Above that it works ok. guessing around 2100rpm and up it is real good around 2500 rpm I think I am making 6psi boost and then it is fine until max boost and EGT go crazy.
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Anyone find me an adjustable fuel pressure regulator rated for DIESEL that doesn't cost over 100.00?
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Anyone find me an adjustable fuel pressure regulator rated for DIESEL that doesn't cost over 100.00?
diesel is nicer than gas to rubber seals..
anything rated for gas should happily take diesel..
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I don't know. Seems to me like diesel and rubber don't get along. Maybe I have just had bad luck? I have always had trouble unless it was diesel rated stamped on the rubber or stating it was OK
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i used to clean my motorcycle oil filter elements in diesel, forever.. then one day we didnt have any, so i soaked it in gasoline, and destroyed the rubber seals in no time.. it was amazing the difference between the 2 solvents
besides, doesnt gas come from higher up on the evap tower at the refinery?
that means they refine diesel even more to get gas from it..
i dont see how diesel would be any worse than gas.
i can leave a seal sitting in diesel for weeks, with no problems. throw that same seal in a container of gasoline, and BAM! its twice as big, and super duper soft..
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I guess.
I just seem to find if I leak diesel on a rad hose it soaks into it and it turns into a trojan. I don't mess with enough gas powered anymore to remember what it does when that happens. It probably evaporates too fast to mess with it.
I did email some MFG and asked if the regulators would work with diesel and they all said, "no" and that was it. No reason just no.
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I guess.
I just seem to find if I leak diesel on a rad hose it soaks into it and it turns into a trojan. I don't mess with enough gas powered anymore to remember what it does when that happens. It probably evaporates too fast to mess with it.
I did email some MFG and asked if the regulators would work with diesel and they all said, "no" and that was it. No reason just no.
they probably thought you were a retard, and wanted to use it on a common rail engine or something like that..
there are some BRILLIANT people out there, with some BRILLIANT epic fails.. lol.
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(http://www.cs.rochester.edu/~jag/vw/engine/fi/YANMARVESmall2.GIF)
Using the above image for reference, at idle and probably throughout the entire RPM range (possibly not for heavily modified pumps) the feed pump is flowing more fuel than is needed by the engine. This, added to the fact that there is a restriction in the OUTLET banjo bolt creates pressure inside the pump housing. This pressure is the main thing that controls advance. On some pumps it is the only thing. Pressure is regulated by the regulating valve.
The feed pump is a positive displacement pump. What that means is that whatever goes into must come out. Our waterpumps are an example of a non-positive displacement pump (I think that is the term). It basically just spins and will push some of the coolant around. Back to the feed pump. What this means is that flow is related to RPM in a linear fashion. The higher the RPM, the more fuel will be pushed into the pump housing.
At idle, the regulating valve will be partially open. Any fuel that the regulating valve bleeds off to maintain the proper PSI in the pump housing is directed back to the feed side of the feed pump. See below
(http://t1.gstatic.com/images?q=tbn:ANd9GcTv4DfXtpNkFHv0fuBbVjfOOYZL6fH3fH0FnSlk5yj3ayxdfzKUEQ&t=1)
That "extra" fuel is supplementing the amount of fuel that needs to be drawn from the tank. When you mash the go pedal, the balance is upset. More fuel is injected into the engine but the engine and pump RPM has not increased yet. This causes the pressure inside the pump housing to begin to drop. As the pressure begins to drop, the regulating valve begins to close and direct more fuel into the pump housing rather than back into the feed side of the feed pump. The regulating valve is very sensitive so the pressure drop is minimal on our engines.
Yes, the feed pump on the cummins and the VW is the same. When we look at the two engines, the VW has 4800 RPM to make it's power while the cummins has 3000. Going back to the positive displacement feed pump we can see that the VW has an advantage in maintaining internal pump pressure throughout the RPM range. Also consider the fact that a cummins idles around 600 RPM while our VWs are around 800 RPM. That's 30% more flow through the vane pump at idle on our VWs.
Also, on many VE pumps, when you mash the go pedal at idle the amount of fuel injected into the engine is the maximum amount of fuel that will ever be injected into the engine. The exception is starting fuel, or cranking fuel. Bosch has developed many fancy contraptions to modify the fuel curve that make my above statement false, such as the LDA but the point I am trying to make is at idle and WOT a lot of fuel is being injected into the engine.
The above statements are based on a properly calibrated pump. Over the years parts wear and the pump falls out of calibration. Depending on the wear of your pump you may find that a lift pump helps. Like ROR said, it is especially helpful in priming the fuel system for starting.
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besides, doesnt gas come from higher up on the evap tower at the refinery?
that means they refine diesel even more to get gas from it..
Nope, got that backwards... From http://www.emt-india.net/process/petrochemical/Petroleum.htm: "Crude oil is refined into products such as gasoline, asphalt, and waxes by a process called fractional distillation. During the process, the parts, or fractions, of crude oil are divided out successively by their increasing molecular weight. For instance, gasoline has a low molecular weight and vaporizes at a fairly low temperature. This means that at the appropriate temperature, while all of the rest of the oil is still in liquid form, gasoline may be separated out. The remaining oil goes through the same process at a slightly higher temperature, and jet fuel is divided out. Repeating the distillation process several times will separate out several constituents of crude oil, which are then processed and put to a wide range of uses."
Gas is the first (and most abundant) product in crude oil. More than half of each barrel is gasoline, the rest is everything from kerosene to tar. There's only like 3 gallons of diesel in each barrel, so gas is 7 times more abundant than diesel.
I suppose that kind of explains why gasoline is more corrosive... Because it is really kind of the "base" of the crude, and will be able to mix with anything below it in the stack? Whereas diesel is much closer to the rubber products, and less likely to dissolve the rubber? Assuming, of course, it's synthetic rubber (made from petroleum and not from natural latex).
The last paragraph is all conjecture. I hate chemistry. Never was able to understand that magic.
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A lot of diesel sold around here has a small percentage of Biodiesel added (B5)
This would explain the swelling on rubber
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Well, personal experience talking here.
On the VE'd Cummins, the stock diaphragm pump only puts out 5psi max. 3 or so at idle. And only when new. Some people with stock systems and new lift pumps (The old non-intercooled ones. They have a bigger injector) can pull their pressure to 0.
There is a rumor that anything above 16-20psi will blow out the front seal. However, these are on old 20 year old pumps with +200k miles.
I personally ran a Walbro 392 (Max PSI 140, Max flow 85GPH) regulated at 18psi. More power (dropped .2 sec in the 1/4mile), better mileage(+1-2mpgs), less smoke throughout the RPM range but noticed the most @ WOT.
Personal friends run Procomp Black that come regulated at 14psi and the hold up just fine.
If you run the Holley or Procomp black, mount as close to the tank and at bottom or below the tank. They are meant to "push" rather than "pull" the fuel.
If you run greater than 10psi, it does affect the timing piston. IIRC, anything above 13 or 14psi give it full forward advance.
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If you run greater than 10psi, it does affect the timing piston. IIRC, anything above 13 or 14psi give it full forward advance.
Not on a VW pump, and I would be very surprised if the Cummins pumps were different. If you look at the first picture I posted it shows that the added pressure will equally effect both sides of the advance piston, thereby nullifying any effect on timing. I have personally tested this on a test bench with Giles. I forget how high in PSI we went, but it was over 40PSI and the timing gauge did not move.
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besides, doesn't gas come from higher up on the evap tower at the refinery?
Gas is the first (and most abundant) product in crude oil. More than half of each barrel is gasoline, the rest is everything from kerosene to tar. There's only like 3 gallons of diesel in each barrel, so gas is 7 times more abundant than diesel.
Actually if you read the article you quoted a "barrel of crude" (whatever that may be) is only about 25% gasoline. Much more is made by thermal and catalytic "cracking" of the heavier fractions.
The rub here is that "crude oil" is vastly different depending where it is pumped. Venezuelan crude is said to be "heavy" because it is low in lighter fractions like naptha and gasoline and high in oils and tars. Indonesian crude is so "light" that it can be bunkered (burned) in ships w/o being refined. That is why the Japs went into Indonesia very early in WWII. They pumped the crude directly into the Imperial Japanese naval vessels.
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So has anyone yet tried adding a lift pump? I may add a lift pump to my recently acquired Volvo D24 wagon. The vanes appear to be stuck in the feed pump and all it will do is idle. It has an outboard primer bulb between filter and pump and giving it a squeeze will allow the engine to rev up. I am putting off disassembling the pump until I get a clean bench.
That won't answer the question however, but at least I should be able to drive the car.
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I'm running the gas pump in the tank on my mk2 jetta all the time, feeding an AAZ... Did it that way in March this year when I moved the AAZ from the last car it wore out. Haven't had any problems.
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So has anyone yet tried adding a lift pump? I may add a lift pump to my recently acquired Volvo D24 wagon. The vanes appear to be stuck in the feed pump and all it will do is idle. It has an outboard primer bulb between filter and pump and giving it a squeeze will allow the engine to rev up. I am putting off disassembling the pump until I get a clean bench.
That won't answer the question however, but at least I should be able to drive the car.
i got a lift pump, it rocks.
really shines on the top end where the pump would be pulling the most vacuum..
got more power from it, and it seems like better mileage.
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I thought you had a worn out IP though. I was curious about the performance of a lift pump on an otherwise good IP. What is the issue with your IP, BTW.
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I thought you had a worn out IP though. I was curious about the performance of a lift pump on an otherwise good IP. What is the issue with your IP, BTW.
contrary..
my IP was rebuilt less than 15k miles ago. got the paperwork.
it helped out a worn out IP a little bit.
it helped out a brand new IP ALOT!
my issue is that i added a little 2 micron after-filter ahead of the stock filter, and it made the filter work harder to pull fuel thru 2 filters., so i added the lift/primer pump..
holy crap, what a difference it made. the pick up off the bottom end is night and day different. its got considerably more bottom end power, and alot more top end power..
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Maybe I will try adding a lift pump to the 5G while I still have it, and see if there is a difference then..
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its worth a try.
i never even considered it until i had my 2 filters. then i was pleased with the results.
all i used was a cheapo shaker style fuel pump.
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I just ordered a facet 60302 posi flow pump its 5-7 psi and 35gpm shoud work just fine for the old eco. Its gonna be the wifes daily so I'm wiring it to a relay running off the fuel soloniod because i dont trust her to remember to turn it off. I'll post pics when I get it all hooked up. I wont know before and after results though because I just dropped the eco into the original stock 1.6 na jetta. Should be pretty sweet. Oh the pump was 35 bucks shiped from spruce aviation. Way better deal than the pos mr gasket pumps.
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I just ordered a facet 60302 posi flow pump its 5-7 psi and 35gpm shoud work just fine for the old eco. Its gonna be the wifes daily so I'm wiring it to a relay running off the fuel soloniod because i dont trust her to remember to turn it off. I'll post pics when I get it all hooked up. I wont know before and after results though because I just dropped the eco into the original stock 1.6 na jetta. Should be pretty sweet. Oh the pump was 35 bucks shiped from spruce aviation. Way better deal than the pos mr gasket pumps.
You don't need any of that stuff to run your lift pump. There is already a switch 12v source you can tap power from...Its called the Fuel shut off solenoid! I am powering my Mr. Gasket diesel lift pump off of my FSS with out any problems! I also have my Lift pump mounted under the hood, behind the RF strut tower on a bracket that I welded up. They say it MUST be mounted close to the tank...luckily a mk2 GTI is pretty small, technically it is mounted close to the tank! ;D
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How long have you been running that mr gasket.. I was going to use the soilinoid voltage just to power the relay. I'm nervous about putting much added amp draw to that curcuit. That way all that that circuit is running is the fuel soilonid and the relay and then i can run 12vs from the pattery to the relay into the lift pump.
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How long have you been running that mr gasket.. I was going to use the soilinoid voltage just to power the relay. I'm nervous about putting much added amp draw to that curcuit. That way all that that circuit is running is the fuel soilonid and the relay and then i can run 12vs from the pattery to the relay into the lift pump.
ive used the power feed going to the shut off solenoid MANY TIMES..
its a PLENTY BIG ENOUGH circuit.. the solenoid is the ONLY thing it powers..
i would install i right near the tank.. i installed mine under my back seat..
ive just got a normal gasoline pump in my Jetta TD.. its worked great for a LONG TIME..
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How long have you been running that mr gasket.. I was going to use the soilinoid voltage just to power the relay. I'm nervous about putting much added amp draw to that curcuit. That way all that that circuit is running is the fuel soilonid and the relay and then i can run 12vs from the pattery to the relay into the lift pump.
I haven't had any issues and nobody else running them that way has as far as I know. I had a complicated circuit like you wish to use before a well known guru told me better! ;)
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That is awesome news. I will defently do that. I have an after market fuel water seperator on a bracket just below the thank that the new pump will fit on. Thanks for the input guys.
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That is awesome news. I will defently do that. I have an after market fuel water seperator on a bracket just below the thank that the new pump will fit on. Thanks for the input guys.
exactly where i was gonna mount mine. probably gonna pickup a mr gasket diesel unit from oreilly auto.
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That is awesome news. I will defently do that. I have an after market fuel water seperator on a bracket just below the thank that the new pump will fit on. Thanks for the input guys.
exactly where i was gonna mount mine. probably gonna pickup a mr gasket diesel unit from oreilly auto.
O'sh*ttys charges ALOT for the mr gasket diesel pump..
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That is awesome news. I will defently do that. I have an after market fuel water seperator on a bracket just below the thank that the new pump will fit on. Thanks for the input guys.
exactly where i was gonna mount mine. probably gonna pickup a mr gasket diesel unit from oreilly auto.
O'sh*ttys charges ALOT for the mr gasket diesel pump..
I cant find a dzl one anywhere else except at diesel shop charging 100 dollars for one and having to order.
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I had nothing but problems with my mr gasket. I highly recomend facet pumps. I run a bigger facet pump one on my 7.3 idi. Its sold by an aircraft supplier wich i would assume means its good enough for something that defies gravity.
Check out
http://www.aircraftspruce.com/catalog/eppages/solidstatepump.php?clickkey=7286
5-7 psi. 35 dollars and some change.
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would a lower flow one be more ideal for a 1.6?
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they also sell a 2-5 psi. some one mentioned that 5psi was ideal.
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I have never found even used gasoline pumps to have any trouble with diesel. Sometimes they hang up if I leave veg in them.
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I have never found even used gasoline pumps to have any trouble with diesel. Sometimes they hang up if I leave veg in them.
all ive ever used is gasoline pumps..
they work fine as long as your tank doesnt have a bunch of crap in it..
there is no MAGIC NUMBER as to what the pump likes to be fed..
tyler and giles proved that you can feed a pump with 150psi at the inlet, and it changes nothing..
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Facet posi flo arrived today! whats a good filter to run between it and the fuel tank it says in instructions one is required...
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how about no filter. Mine came with a small filter at the outlet of the pump that i deleted with a brass fitting from the hardware store.
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Facet posi flo arrived today! whats a good filter to run between it and the fuel tank it says in instructions one is required...
no filter on my setup..
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Id run it up in the bay after the filter and before the injection pump.
If you insist on having it under the car, some sort of capable in line filter will suffice to keep it clean of tank gunk.
Other people that haven`t used a filter were lucky enough to have a clean tank it seems. Will you be so lucky? Or will the pump die in short order?
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Id run it up in the bay after the filter and before the injection pump.
If you insist on having it under the car, some sort of capable in line filter will suffice to keep it clean of tank gunk.
Other people that haven`t used a filter were lucky enough to have a clean tank it seems. Will you be so lucky? Or will the pump die in short order?
i like putting it BEFORE my filters.. then the filters are pressure fed, and they last soo much longer..
dont remember the last time i changed fuel filters!
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Don't see how it makes a difference? But anyway. lol I have had my filters on the suction side with no issue?
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Don't see how it makes a difference? But anyway. lol I have had my filters on the suction side with no issue?
suction is suction.. vacuum..
pressure pushes stuff thru the filter, rather than relying on being pulled thru..
pressure fed is better yo..
not saying yours was wrong, but that filters last better with a pressure feed..
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pressure pushes stuff thru the filter
So it is not filtering as much? Yikes. lol
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pressure pushes stuff thru the filter
So it is not filtering as much? Yikes. lol
well, there is obviously filter media present, and i doubt 5psi is literally pushing things thru my filter..
my racor 2 micron filter bowl is still spotless, so i doubt anything gets pushed thru the filters..
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do any MAPS sell racor stuff? I think I'm gonna slap my oe filter out back and put a racor 2micon up front.
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do any MAPS sell racor stuff? I think I'm gonna slap my oe filter out back and put a racor 2micon up front.
i run both filters up front, so its easy to get to them..
(http://i702.photobucket.com/albums/ww28/Dubsmoke/P1000546.jpg)
usually, racor filters arent carried at local parts stores, unless they deal with alot of marine or agriculture stuff..
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Run the pump and regular fuel filter up front. It will make your life 100% easier down the road.
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A pre filter like those on Mercedes will work perfect. Just enough of a filter to keep junk out of the pump. Filter are cheap and can be blown out.
Mercedes run three filter, with just the normal IP mounted lift pump. A in-tank strainer, and a pre filter/filter up front. No issues unless you get microbes.
That's my plan atleast. Still have yet to install the walbro lift pump.