The New Fuel Filter, Filter Head, Lift Pump Thread

dgeist · **Posted:** Wed Jul 18, 2007 1:47 pm

Cowcatcher wrote:

tigafila wrote:

I installed a Racor 245 on Sunday and it has already surpassed the stock unit's time between stalling or no-starts!! Time will tell if there is any air being sucked in at the quick connects by the tank, I'll report more as time goes on. Tigafila

Did you deal with WIF, Temp and heater? How? Pics?

Thanks for being a pioneer.

seconded! Also good to know would be a couple of data points on the electrical characteristics of the factory WIF and temp sensors (in order to match them to the aftermarket replacements).

An Ohmmeter, a glass of water, and an accurate thermometer would be all you'd need for both. Anyone with a spare/damaged unit could do the same (which counts me out).

Dan

bbertram · **Joined:** Mon Dec 19, 2005 4:17 pm **Posts:** 144

With the new filter head and Loctite Gasket Sealent installed in and around the puck o-ring and thread sealent on the bleeder valve I have only had 1 stall and that was today. Took about 600 kms to do it this time, much more time. I wonder though, yesterday my jeep was in the sun and it was so hot out, I started it up and it ran bad for about a block and then all was good. I wonder if the tank pressurized or someplace else with fuel and created air pockets? I'm tracking how many KMs it takes between each stall. So far its far better than every day. Will provide more data as I drive it more.

retmil46 · **Posted:** Wed Jul 18, 2007 6:29 pm

I think we're talking entrained air/vapors literally boiling out of hot diesel fuel.

Diesel fuel, depending on the blend, can have an allowable vapor point of 125 F, but more usually should be 140 F or greater. But when you put any liquid under a vacuum, that can significantly lower the vapor and boiling point.

The other day after a 25 mile run and letting the CRD sit for 45 minutes, the fuel filter head had soaked up heat from the engine to where my infared thermometer read over 130 F. Once I started the beast and let fuel run thru it for 2 minutes, that temp had dropped by 20 F.

Even with zero leaks on my filter head, last week I had to burp the fuel filter again - it took longer than normal to crank, and sure enough I had air/vapor built up in the filter.

Since getting the lift pump operating back on Monday, I've been able to verify no fuel system leaks at 3 to 4 psi, hand primer pump stays hard for hours after shutdown, and zero air/vapor in the filter.

From some research Ranger1 has done, it seems a combination of heat, vacuum, and 2 micron filtration acts to literally boil and strip the entrained air out of the fuel. The recommendations he found to avoid this follow along the path we're already on - a lift pump that can maintain at least 3 psi at the suction of the injection pump, and a fuel cooler somewhere in the loop to keep fuel temp from approaching anywhere near 140 F.

tigafila · **Posted:** Wed Jul 18, 2007 10:39 pm

I should have explained better. I had to connect the fuel temp sensor to get the check engine light off, the connector for the heater looked similar but wouldn't connect. I left the hockey puck in the engine bay tied out of harms way and didn't splice in the pig tail for the heater yet. The filter has a large bowl on the bottom for water seperation so that'll be good enough. I'm out of town now but will post pics when I get back, but the wife says she's still running great and that's good enough for me. Tigafila

Stan Wright · **Posted:** Thu Jul 19, 2007 12:34 pm

Tigafila - Where did you get your Racor unit?

I haven't been driving my CRD as much lately as it has been motorcycle weather, but I've noticed after my Jeep has been left idling for awhile (car wreck, medical scene...volunteer firefighter) when I leave the scene it seems to be in limp mode (sluggish, poor throttle response) for about 30 seconds then returns to normal. Air buildup?

I've been away from the forum for awhile. This is a great thread.

dgeist · **Posted:** Thu Jul 19, 2007 2:35 pm

retmil46 wrote:

I think we're talking entrained air/vapors literally boiling out of hot diesel fuel.
Since getting the lift pump operating back on Monday, I've been able to verify no fuel system leaks at 3 to 4 psi, hand primer pump stays hard for hours after shutdown, and zero air/vapor in the filter.

From some research Ranger1 has done, it seems a combination of heat, vacuum, and 2 micron filtration acts to literally boil and strip the entrained air out of the fuel. The recommendations he found to avoid this follow along the path we're already on - a lift pump that can maintain at least 3 psi at the suction of the injection pump, and a fuel cooler somewhere in the loop to keep fuel temp from approaching anywhere near 140 F.

Here's a thought related to the filter head staying hot: could the factory-recommended cool-down time be a factor here? Also, would the sheer fact that the puck is made of high-density plastic make the factory system retain heat longer than the aluminum head alone (and therein be allowing the above process more easily by indsulating the hot fuel in the system...)?

Dan

tigafila · **Posted:** Thu Jul 19, 2007 9:20 pm

I started by contacting my local Racor dealer to order one, they tried to order one and Racor had none in stock and would be three weeks to make some. I was looking at probably 4 weeks to get it, I told the local dealer it was too long and he offered to call Racor and ask who might have one on the shelf. He called me back and said "you might as well just get it from them, if I get it for you I'll have to mark it up" (pretty nice guy). The company he referred me to is Brookline Machine co. 617-782-4018. It was under $200 with an extra 2 micron filter, heated bowl, and shipping. It's a nice unit with a bleeder, a check valve so air doesn't get back in while bleeding and a hand primer pump. It does bolt right up to the factory studs. Tigafila

Stan Wright · **Posted:** Fri Jul 20, 2007 1:10 am

Here's a nice pdf file describing the Racor 200 series filters:

http://www.parker.com/EAD/Digital_asset ... t_id=28529

bbertram · **Joined:** Mon Dec 19, 2005 4:17 pm **Posts:** 144

Stalled again, I think its heat related. I was at the ND state fair and she died on me in the parking lot. Primed it and not a problem since. It seems to only stall when its blistering hot outside and after its been running. Maybe a heat shield around the filter area would be good. Or some heat reflective tape around the filter?

Cowcatcher · **Posted:** Mon Jul 23, 2007 11:11 am

I wonder if pushing the fuel through the high pressure pump heats the bypassed fuel enough, particularly if you are say at a 1/4 of a tank, to continue ramping up the heat of the fuel to cause this problem.

retmil46 · **Posted:** Mon Jul 23, 2007 5:13 pm

I think it's a combination of heat soak - the filter, filter head, and fuel lines in the engine bay absorbing heat from the engine, particular at idle in park with no air flow, and also for at least a couple of hours after shutdown - and the hot return fuel being pumped back to the tank.

And yes, if you assuming a constant heat transfer rate (ie, driving at a steady speed on a long trip), you're going to continue dumping more heat into a decreasing amount of fuel in the tank. And as the fuel being supplied from the tank goes up in tenperature, the fuel being returned to the tank is going to get hotter as well.

The other day, Ranger1 went for a trip when he was just above 1/4 tank, and stopped to fill up after 45 miles. He left the engine running, and before filling up hooked up to the fuel temp sensor to see what fuel temp was. The fuel being supplied from the tank registered 120 F at the filter! :shock:

After only 45 miles of local driving, enough heat had been transferred into the fuel and fuel tank, to raise the temp of the fuel in the tank nearly 40 F.

And we have an electric fuel heater for WHAT reason?

After he filled the tank, he noticed the engine sounded much quieter. He checked the fuel temp sensor again. With a full tank of relatively cold fuel, fuel temp at the filter now registered 90 F. Dumping in 18 gallons of cold fuel had absorbed enough heat to lower the fuel temp by 30 F.

Based on what I saw on a 50 mile trip a couple of weeks ago, where I checked temps before, during, and after with an infared thermometer, I'd estimate the heat transfer rate to be at least 1500 BTU/hour into the fuel tank.

This is based on a full tank of 20 gallons, vehicle parked for 3 days and at ambient of 85 F, specific heat capacity of #2 diesel being 0.5 BTU/lbm-degF, density of #2 diesel approximately 7.25 lbs/gallon, 20 F rise in temp measured on the surface of the tank, after a 50 mile round trip of approximately 1 hour driving time with a 45 minute stop between legs.

Given that during the 45 minute stop the fuel tank may have given up some of it's heat, the actual heat transfer rate may be higher than what I calculated above.

I know that during the 45 minute stop, the fuel filter and head had heat soaked from 110 F (measured while still idling just after I parked at my destination) to nearly 135 F before I started it for my return trip. After starting the engine and letting it idle for 2 minutes, fuel from the tank going thru the filter had dropped this temp back down to 115 F.

Now you know why I busted my rear last week and put insulation sleeving on the fuel lines and filter in the engine bay, and managed to get a fuel cooler installed in the return line. I've though of the heat shield idea as well, at least for the filter head, and I'm going to try rigging one up when I get the chance.

Cowcatcher · **Posted:** Mon Jul 23, 2007 6:40 pm

Perhaps we need to get that cup holder with the cooler from the Caliber and wrap it around the filter.

Cowcatcher · **Posted:** Mon Jul 23, 2007 7:00 pm

I spotted a British CRD user on Jeep KJ Country with a 2004 CRD and asked him which fuel head his 2.8 had. He has the Racor so we know that it was used at least one year on the 2.8 CRD.

Anomious · **Posted:** Tue Jul 24, 2007 12:59 am

Wow!! I just saw a feral goose run through here!
:lol:

LK

Pablo · **Joined:** Thu Feb 02, 2006 10:06 pm **Posts:** 1201

retmil46 wrote:

I think it's a combination of heat soak - the filter, filter head, and fuel lines in the engine bay absorbing heat from the engine, particular at idle in park with no air flow, and also for at least a couple of hours after shutdown - and the hot return fuel being pumped back to the tank.

And yes, if you assuming a constant heat transfer rate (ie, driving at a steady speed on a long trip), you're going to continue dumping more heat into a decreasing amount of fuel in the tank. And as the fuel being supplied from the tank goes up in tenperature, the fuel being returned to the tank is going to get hotter as well.

The other day, Ranger1 went for a trip when he was just above 1/4 tank, and stopped to fill up after 45 miles. He left the engine running, and before filling up hooked up to the fuel temp sensor to see what fuel temp was. The fuel being supplied from the tank registered 120 F at the filter! :shock:

After only 45 miles of local driving, enough heat had been transferred into the fuel and fuel tank, to raise the temp of the fuel in the tank nearly 40 F.

And we have an electric fuel heater for WHAT reason?

After he filled the tank, he noticed the engine sounded much quieter. He checked the fuel temp sensor again. With a full tank of relatively cold fuel, fuel temp at the filter now registered 90 F. Dumping in 18 gallons of cold fuel had absorbed enough heat to lower the fuel temp by 30 F.

Based on what I saw on a 50 mile trip a couple of weeks ago, where I checked temps before, during, and after with an infared thermometer, I'd estimate the heat transfer rate to be at least 1500 BTU/hour into the fuel tank.

This is based on a full tank of 20 gallons, vehicle parked for 3 days and at ambient of 85 F, specific heat capacity of #2 diesel being 0.5 BTU/lbm-degF, density of #2 diesel approximately 7.25 lbs/gallon, 20 F rise in temp measured on the surface of the tank, after a 50 mile round trip of approximately 1 hour driving time with a 45 minute stop between legs.

Given that during the 45 minute stop the fuel tank may have given up some of it's heat, the actual heat transfer rate may be higher than what I calculated above.

I know that during the 45 minute stop, the fuel filter and head had heat soaked from 110 F (measured while still idling just after I parked at my destination) to nearly 135 F before I started it for my return trip. After starting the engine and letting it idle for 2 minutes, fuel from the tank going thru the filter had dropped this temp back down to 115 F.

Now you know why I busted my rear last week and put insulation sleeving on the fuel lines and filter in the engine bay, and managed to get a fuel cooler installed in the return line. I've though of the heat shield idea as well, at least for the filter head, and I'm going to try rigging one up when I get the chance.

Wow. I have noticed that filling up gives me drastically better performance-- but only sometimes. It would also stop the shuddering (sometimes). That was back before I started burping the air out and back when the heater was still plugged in. This also explains the hot starts and the gutless motor after idling when its hot out.

I suppose when your in AZ and the temp is already 115 outside, that fuel bakes. I think I am going to pull the trigger on some fuel line mods, but I will try and wait till warranty is out. I am going to give Southwest Diesel and Electric a call and see what they say about this whole mess. I might do the fuel cooler, Racor fuel filter and maybe a lift pump and some hood vents (louvers) to boot.

What about wrapping the fuel line in header tape? Does most of the heat transfer come from the fuel line, or the filter? What if I wrapped the outside of the filter too?

Cowcatcher · **Posted:** Tue Jul 24, 2007 2:09 am

If the fuel return is on the high side it may be that too much insulating would actually hurt. As I recall from drharv's situation the return is on the high side since speculation was that the return valve was stuck open an not allowing the common rail to build pressure. If you are taking the the fuel from 3>4 PSI to like 15,000 it will heat up just like air in a bicycle pump. If that is the source of the heat then insulating the return lines will cap the heat in like a thermos.

RFCRD · **Posted:** Tue Jul 24, 2007 6:10 am

retmil46 wrote:

The other day, Ranger1 went for a trip when he was just above 1/4 tank, and stopped to fill up after 45 miles. He left the engine running, and before filling up hooked up to the fuel temp sensor to see what fuel temp was. The fuel being supplied from the tank registered 120 F at the filter! :shock:

Understand your concern about high fuel temps & vaporization but think your efforts may be self-defeating. Detroit Diesel's research in the '80's found hot diesel fuel temps (in the 120* F+ range) is where you will get the best combustion and fuel economy. This computer control package should be measuring fuel temp and adjusting injector pulse/timing to optimize efficiency or emissions. I believe that is a primary reason why mine wouldn't deliver over 24 mpg until the outside temps were in the 90's and would drop off sharply under 40*F. You may see these temps frequently in the South, but it's a mid-Summer only thing in Ohio. High temps may be causing some fuel vaporization but these temps are likely where the engineers want them to be for optimization.

Jeger · **Posted:** Tue Jul 24, 2007 6:19 am

RFCRD wrote:

retmil46 wrote:

The other day, Ranger1 went for a trip when he was just above 1/4 tank, and stopped to fill up after 45 miles. He left the engine running, and before filling up hooked up to the fuel temp sensor to see what fuel temp was. The fuel being supplied from the tank registered 120 F at the filter! :shock:

Understand your concern about high fuel temps & vaporization but think your efforts may be self-defeating. Detroit Diesel's research in the '80's found hot diesel fuel temps (in the 120* F+ range) is where you will get the best combustion and fuel economy. This computer control package should be measuring fuel temp and adjusting injector pulse/timing to optimize efficiency or emissions. I believe that is a primary reason why mine wouldn't deliver over 24 mpg until the outside temps were in the 90's and would drop off sharply under 40*F. You may see these temps frequently in the South, but it's a mid-Summer only thing in Ohio. High temps may be causing some fuel vaporization but these temps are likely where the engineers want them to be for optimization.

Was their fuel under a vacuum though? I dont disagree that hot fuel may produce better combustion in a diesel, but I dont think gulping air is helping anything.

Perhaps a lift pump alone would be best? Get rid of that vacuum and raise the vaporization/boiling point higher than the temps we are seeing? An air trap that you could check at a glance would be nice....gotta finish that little project

tigafila · **Posted:** Tue Jul 24, 2007 6:37 pm

As promised here's the update on the Racor. Nothing to report!!!!! Not one stall, hesitation, no-start, nothing and it's been about 1000 miles. I'm actually driving it on a road trip right now (which is awesome because I never get to drive it) where I'll probably put on about another 1000 miles in the Apalachian and Blue Ridge mountains so that should be a good test. I'll stick my head in the lion's mouth again and say what a great driving vehicle (the last time I said that 5 minutes later the trans temp light came on and the torque converter failed). Tigafila

onthehunt · **Posted:** Tue Jul 24, 2007 7:26 pm

Quote:

Understand your concern about high fuel temps & vaporization but think your efforts may be self-defeating. Detroit Diesel's research in the '80's found hot diesel fuel temps (in the 120* F+ range) is where you will get the best combustion and fuel economy. This computer control package should be measuring fuel temp and adjusting injector pulse/timing to optimize efficiency or emissions. I believe that is a primary reason why mine wouldn't deliver over 24 mpg until the outside temps were in the 90's and would drop off sharply under 40*F. You may see these temps frequently in the South, but it's a mid-Summer only thing in Ohio. High temps may be causing some fuel vaporization but these temps are likely where the engineers want them to be for optimization.

I agree.

The New Fuel Filter, Filter Head, Lift Pump Thread

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