Hello everyone! I have changed a lot of GM Fuel Pumps but this is the first time I've seen a Fuel Pump Pulsator Dampener. Its in my V6 Fiero. Usually there is a short piece of fuel hose with 2 plastic clamps holding the fuel pump in place. So Do I really need a Fuel Pump Pulsator Dampener Installed with my new FP? Also, do you think mechanics are installling this part with a new fuel pump, or just a short piece of hose?
Thanks for you time!!!
[This message has been edited by Alex.07.86GT (edited 09-06-2014).]
Also depends on pump used to replace old one. Some pumps don't use pulsators. Most have this in the install notes.
High or Low pressure? Low pressure units of any type often don't use them. "Old" design high pressure do.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
If you use a modern turbine style fuel pump then no pulsator is needed. I believe that older fuel pumps were primarily gyrator style pumps that used the pulsator to smooth out the flow and reduce noise.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
While not needed with a turbine style pump, the damper is impervious to attack from fuel. The hose that comes with the new fuel pumps? I have seen failures due to chemical attack in as little as three months....... I reinstall the dampener.
I installed the rotary Bosch fuel pump in my 85 GT and did not use the pulsator. Can't even hear the fuel pump running and it works great. Make sure you use hose intended for immersion in gasoline and you will have no worries about degradation.
Originally posted by theogre: High or Low pressure? Low pressure units of any type often don't use them. "Old" design high pressure do.
Would the EP240 pump (ACDelco OEM replacement for L44) be considered high or low pressure?
I just had my tank redone and am changing the pump tonight. I was planning on using the bypass hose provided with the new pump and remove the pulsator dampener, but now this thread has me doubting.
I also read a few posts on here where people used their old pulsator dampener and if failed a few weeks after they replaced the fuel pump (guessing the new pump works better and kills the old pulsator dampener?)
------------------ Ben 87 GT / 88 GT 84 Indy #1863
I am guessing the ethanol used in fuel might be causing the fuel hose problems. The pulsator is not needed on modern fuel pumps and I would think that the ethanol would affect the rubber in the pulsator too. I have only had the new pump in for about a year so I am not sure how the supplied hose will hold up but its working great so far. I wonder if later model cars use a rubber hose in the tank and if so is it a better grade rubber?
I just did a search and found that Gates offers submersible fuel line hose specifically designed for in tank fuel pumps. I would imagine you local parts store would have it.
Would the EP240 pump (ACDelco OEM replacement for L44) be considered high or low pressure?
I just had my tank redone and am changing the pump tonight. I was planning on using the bypass hose provided with the new pump and remove the pulsator dampener, but now this thread has me doubting.
I also read a few posts on here where people used their old pulsator dampener and if failed a few weeks after they replaced the fuel pump (guessing the new pump works better and kills the old pulsator dampener?)
IMO using the old pulsator is not Good!! Especially since it is a fuel passage point with the FP's highest pressure.
Also, will the new pumps always be the correct size for the pulsator? Will it leak fuel?
I am guessing the ethanol used in fuel might be causing the fuel hose problems. ... I would think that the ethanol would affect the rubber in the pulsator too.
E10 fuel had been in widespread use for more than a decade when the 1988 Fiero was manufactured. Ethanol is not the issue.
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I have only had the new pump in for about a year so I am not sure how the supplied hose will hold up but its working great so far. I wonder if later model cars use a rubber hose in the tank and if so is it a better grade rubber?
The issue is that the rubber used in the inner liner of ordinary fuel hose is compatible with pure gasoline and E10, but the rubber used for the outer jacket is not. Submersible fuel hose is what you need for in-tank use; both the inner and outer rubber jackets are fuel compatible. Unfortunately, a lot of people have reported that the hose included with their new fuel pumps apparently was not the submersible kind, because it deteriorated and failed within a couple of years. Submersible fuel hose is expensive.
[This message has been edited by Marvin McInnis (edited 09-08-2014).]
I agree. But a brand new pulsator is about $20 ... far less than the cost of your new fuel pump, and not much more than the price of a foot of submersible fuel hose.
[This message has been edited by Marvin McInnis (edited 09-08-2014).]
While not needed with a turbine style pump, the damper is impervious to attack from fuel. The hose that comes with the new fuel pumps? I have seen failures due to chemical attack in as little as three months....... I reinstall the dampener.
Yes this has happened when std SAE 30R9 fuel injection line is supplied to make the connection. If you use 30R10 submersible fuel injection hose it will last - 3 years on my 3800SC swap and not a hint of a problem. ------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 09-08-2014).]
Yes this has happened when std SAE 30R9 fuel injection line is supplied to make the connection. If you use 30R10 submersible fuel injection hose it will last - 3 years on my 3800SC swap and not a hint of a problem.
Two feet lasted us about 3 years and currently don't keep much here in the shop but you can get on eBay here : http://www.ebay.com/itm/Gat...d207551e2078d%26pid% 3D100005%26prg%3D10073%26rk%3D3%26rkt%3D6%26sd%3D280971433795&rt=nc
$10 should give you enough for a lifetime buy.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I have had the submersible hose go bad too. The main thing that causes the hoses to go bad is bad gas, when gas sits and breaks down it does all kinds of bad things to the tank, sending unit, pump and hose. Just an FYI
Two feet lasted us about 3 years and currently don't keep much here in the shop but you can get on eBay here : [URL=http://www.ebay.com/itm/Gates-27335-Fuel-Injection-5-16-Inch-Fuel-Hose-2FT-2-Feet-225-PSI-MADE-IN-US/400587277495?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D23490%26meid%3De02b32d7fc9c4a658d6d207551e2078d%2 6pid%]http://www.ebay.com/itm/Gat...d207551e2078d%26pid%[/URL] 3D100005%26prg%3D10073%26rk%3D3%26rkt%3D6%26sd%3D280971433795&rt=nc
I have had the submersible hose go bad too. The main thing that causes the hoses to go bad is bad gas, when gas sits and breaks down it does all kinds of bad things to the tank, sending unit, pump and hose. Just an FYI
This is interesting info although I have not experienced it with SAE 30R10 hose. Are you sure that the hose you used had 30R10 submersible fuel injection line stamped on it? What I dislike about the pulsators is that they are not clamped on the fuel feed line. They just slip in place. With a higher capacity/pressure pump they don't give me a warm and cozy feeling against leakage.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I used a neoprene "hose" on mine (white 'milky' looking line available at Home Depot). A friend had some in a Fiero tank that he pulled out of a car & it appeared that it had worked fine without deterioration. You can't tell me that ethanol is not the culprit here. I've never seen this problem before it was introduced, & I've seen a LOT of documentation where it caused all kinds of problems in other vehicles. Search & you'll see - it's especially bad in the '70s & '80s cars & a lot of boats. Gee THANKS Congress for giving us this "gift", that reduces gas mileage & f**ks up our cars & boats! (not to mention all the BS with corn subsidies, shortages, & higher prices!) ~ Paul aka "Tha Driver"
This is interesting info although I have not experienced it with SAE 30R10 hose. Are you sure that the hose you used had 30R10 submersible fuel injection line stamped on it? What I dislike about the pulsators is that they are not clamped on the fuel feed line. They just slip in place. With a higher capacity/pressure pump they don't give me a warm and cozy feeling against leakage.
The higher the pressure, the tighter the dampener seals. Look how it is designed.
Fiero V6 etc working (from pump to engine) pressure ~45psi and is medium to high pressure depending on what doc's. Some current engines run 100+ PSI fuel pressure.
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Originally posted by Dennis LaGrua: What I dislike about the pulsators is that they are not clamped on the fuel feed line. They just slip in place. With a higher capacity/pressure pump they don't give me a warm and cozy feeling against leakage.
Pulsator is made to connect hard lines. Push-on method is use by higher pressure systems then most fuel pump make. Many new cars/trucks have Plastic hard lines w/ push-on connections. Pressure makes these tight in use but easy to work on w/ pump is off and system is bled of pressure.
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Originally posted by Dennis LaGrua: Two feet lasted us about 3 years and currently don't keep much here in the shop but you can get on eBay here : http://www.ebay.com/itm/Gat...658d6d207551e2078d%2 6pid%
$10 should give you enough for a lifetime buy.
That hose is for lines outside of tank. Gates, who packages them for NAPA, has two types of Barricade hoses... Low and high pressure and Both types are not rated for in tank use.
Submersible Fuel Line Hose are on page 3 of same PDF. Available in 1' and 10' packs.
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Ordinary fuel line hose is designed to handle fuel on the inside only. The Gates Submersible Fuel Line Hose Exceeds the SAE 30R10 rating and is capable of handling gasoline, alcohol-extended gasoline or diesel fuel in fully immersed, mobile, stationary and marine applications.
Fiero V6 etc working (from pump to engine) pressure ~45psi and is medium to high pressure depending on what doc's. Some current engines run 100+ PSI fuel pressure.
Thanks for pointing out the error. The hose that I have in my shop, shown in the picture is the correct SAE 30R10 submersible fuel line. The eBay link does not lead to that hose for sale. It is standard FI hose. The three year (almost 4 yr) hose in my tank is the 30R10 hose and its holding up fine and still doing its job. Note that the hose connection sections sold with some fuel pumps are not always submersible fuel line. If the pump is a Chinese import you can bet that it doesn't come with the right hose.
I'm sure it has mostly to do with bad/old gas. I have seen gas last for years, other gas turns bad in a few months. Bad gas kills pumps, kills sending units, rusts tanks, etc. other wise I have seen tanks that are in constant use and look spotless inside. So I would assume it is the bad gas attacking the hose in the tank and turns it to goo. Where gas alone won't do it. Like I saw one Fiero, brand new pump, worked fine, then sat for 4 months, dead pump. Haven't pulled it yet to see what the hose looks like, but we only use the submersible hose and I can't say I would use it twice, where I have yet to pull out a bad pulsator, thus why I went back to one. and as said above the higher the pressure the greater the sealing effect of the pulsator, and the rubber on them always looks nice and clean. I have dropped way too many tanks to count, prob over 50, some hoses look fine some are like gooey tar, but seeing enough hoses get a split in them and not seeing a bad pulsator, my vote goes to the pulsator.
I'm sure it has mostly to do with bad/old gas. I have seen gas last for years, other gas turns bad in a few months. Bad gas kills pumps, kills sending units, rusts tanks, etc. other wise I have seen tanks that are in constant use and look spotless inside. So I would assume it is the bad gas attacking the hose in the tank and turns it to goo. Where gas alone won't do it. Like I saw one Fiero, brand new pump, worked fine, then sat for 4 months, dead pump. Haven't pulled it yet to see what the hose looks like, but we only use the submersible hose and I can't say I would use it twice, where I have yet to pull out a bad pulsator, thus why I went back to one. and as said above the higher the pressure the greater the sealing effect of the pulsator, and the rubber on them always looks nice and clean. I have dropped way too many tanks to count, prob over 50, some hoses look fine some are like gooey tar, but seeing enough hoses get a split in them and not seeing a bad pulsator, my vote goes to the pulsator.
I dont think the bad gas kills the hoses. In my tank the 20yro gas melted the foam FP cover and did no other damage to the other rubber parts & wires. There was a weird coating of sludge or mold or something on everything that came off quickly with the AWESOME product I used. The pulsator cleaned up well too. My new pump came with a short hose that I wont use bcause it doesnt say SAE 30R10. I wont use the foam FP cover supplied either. I dont know if a new pulsator will fit my new pump so I bought the 1ft Gates 27093 Submersible 30R10 hose from Amazon @ $20. **SUBMERSIBLE hose (SAE 30R10) will not dissolve in any kind of fuel or good fuel or bad fuel!***
[This message has been edited by Alex.07.86GT (edited 09-11-2014).]
Just finished replacing the pump on the Indy because of low fuel pressure, and used the connection hose they supply with the new pump. Problem fixed.
Afterwards, I thought that perhaps the new Dorman pulsation damper I installed at the time was the problem. I tested it with a vacuum pump and it holds ZERO vacuum - so it's the source of the fuel pressure "leak" and probably nothing wrong with the pump I took out.
Originally posted by fierosound: Afterwards, I thought that perhaps the new Dorman pulsation damper I installed at the time was the problem. I tested it with a vacuum pump and it holds ZERO vacuum - so it's the source of the fuel pressure "leak" and probably nothing wrong with the pump I took out.
How would one go about testing the pulsator dampener with a vacuum pump? Connect the vacuum on the output, pump and put your finger on the other end to see if suction occurs?
------------------ Ben 87 GT / 88 GT 84 Indy #1863
How would one go about testing the pulsator dampener with a vacuum pump? Connect the vacuum on the output, pump and put your finger on the other end to see if suction occurs?
I honestly don't remember seeing any markings on either Bosch fuel pump I installed. When I put mine in I didn't use plastic clamps on the hose I used stainless clamps.
The pulsator is old technology and is not needed with modern electric fuel pumps, fuel hose degradation is a separate issue.
Would someone here know if the new OEM ACDelco EP240 pumps are turbine pumps?
I'm reading the Bosch pumps are, unsure if the ACDelco ones are as well (can't find any reference on ACDelso's site nor in the pump instruction booklet).
*EDIT*: ACDelco's website mentions: "Pump changed from a roller vane design to a gerotor design." ... gerotor=turbine?
Thanks.
[This message has been edited by benoitmalenfant (edited 09-16-2014).]
*EDIT*: ACDelco's website mentions: "Pump changed from a roller vane design to a gerotor design." ... gerotor=turbine?
I can see how the roller vane would create pulses that need to be buffered.
The rotary vane design, which many brands use for high-volume high-pressure fuel pumps, have multiple sliding vanes (3) that are driven by a spindle (2). As they rotate, each vane slides out, sealing to the wall of the cavity. The fuel gets trapped between two vanes and pressurizes as the cavity gets smaller towards the outlet. The roller vane pump is the same except the square vanes are replaced with rollers.
Here is an diagram of a georotor pump. The spur gear in the center drives an internal ring gear, which pulls the fluid into the cavity, compresses it through the crescent-moon form in the center and pushes it out under pressure. These pumps are the most efficient of all the designs.
I can see how the roller vane would create pulses that need to be buffered.
The rotary vane design, which many brands use for high-volume high-pressure fuel pumps, have multiple sliding vanes (3) that are driven by a spindle (2). As they rotate, each vane slides out, sealing to the wall of the cavity. The fuel gets trapped between two vanes and pressurizes as the cavity gets smaller towards the outlet. The roller vane pump is the same except the square vanes are replaced with rollers.
Here is an diagram of a georotor pump. The spur gear in the center drives an internal ring gear, which pulls the fluid into the cavity, compresses it through the crescent-moon form in the center and pushes it out under pressure. These pumps are the most efficient of all the designs.
Just finished replacing the pump on the Indy because of low fuel pressure, and used the connection hose they supply with the new pump. Problem fixed.
Afterwards, I thought that perhaps the new Dorman pulsation damper I installed at the time was the problem. I tested it with a vacuum pump and it holds ZERO vacuum - so it's the source of the fuel pressure "leak" and probably nothing wrong with the pump I took out.
They will never hold vacuum, they are designed to hold pressure only, and to do it well.
I guess I'll rig something up to test with air then.
IMO if your new pump doesnt need it then dont use it! Its just added weight on the fuel sender or just something else to get rusty, collect dirt! Most interesting, is that it doesnt clamp on! or Will it really work on your new fuel pump(not leak) when the pump came with a hose???
[This message has been edited by Alex.07.86GT (edited 09-22-2014).]
