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Re: Need help diagnosing fueling issue from Open Road Race
[Re: Mopar_Rich]
#1613171
04/30/14 08:09 PM
04/30/14 08:09 PM
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Joined: May 2005
Posts: 723
Houston Tx
Uhcoog1
OP
super stock
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OP
super stock
Joined: May 2005
Posts: 723
Houston Tx
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Quote:
There are several mistakes people make with inline pumps - but if you take care of these, inline pumps work fine.
1) They should be gravity fed! That means a bung in a sump welded to the bottom on the tank and the inline pump mounted below that. A bung by itself will still have issues if the bung is not installed in a sump or some other means to keep from sucking air.
2) Since many people don't bother to install a sump or some other means to eliminate the possibility of sucking air - even with a bung - never run the fuel tank below 1/2 full.
The real solution ... buy a good tank with an internal sump and the pump mounted in the tank.
This is in line with my thinking. The walbro GSL392 and the in tank GSS series are both gerotor design pumps. If neither has to lift fuel, neither are run dry, and neither get excessively hot, there shouldn't be a difference in performance, longevity, etc.
-'02 Dodge Viper Ex-World Challenge racecar
-'73 Duster, 6.1 based 392 hilborn hemi, tko600, full floater rear 9", Hellwig custom bars, viper brakes, built for road course
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: Uhcoog1]
#1613172
04/30/14 08:43 PM
04/30/14 08:43 PM
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Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Challenger 1
Too Many Posts
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Too Many Posts
Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
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Quote:
Quote:
Seems like the in-tank pump is the only real solution to this issue.
This is true, external electric fuel pumps are not the answer, no matter how tricked out it is.
Tell me why you believe this to be true.
Because there are too many heat sources to avoid externally, not really a good place on most cars to mount a external electric pump and have it gravity fed the whole time, harder to keep the sump covered when the line exits on one side of the tank verses a internal pump is in the center usually. The column of gas inside the tank helps create a positive inlet pressure for the internal pump. Which is also cooled by the gas in the tank.
There are more advantages to having it in the tank. Safety, cheaper, simpler and more. Good luck.
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: Challenger 1]
#1613173
04/30/14 09:52 PM
04/30/14 09:52 PM
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Joined: May 2005
Posts: 723
Houston Tx
Uhcoog1
OP
super stock
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OP
super stock
Joined: May 2005
Posts: 723
Houston Tx
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Quote:
Quote:
Quote:
Seems like the in-tank pump is the only real solution to this issue.
This is true, external electric fuel pumps are not the answer, no matter how tricked out it is.
Tell me why you believe this to be true.
Because there are too many heat sources to avoid externally, not really a good place on most cars to mount a external electric pump and have it gravity fed the whole time, harder to keep the sump covered when the line exits on one side of the tank verses a internal pump is in the center usually. The column of gas inside the tank helps create a positive inlet pressure for the internal pump. Which is also cooled by the gas in the tank.
There are more advantages to having it in the tank. Safety, cheaper, simpler and more. Good luck.
Have you run an in tank pump in a factory Mopar tank?
I chose the external pumps with accumulator because it's dependable for road course work, it keeps the fuel system out of the trunk, and it's fairly cheap. The options for an in-tank conversion for a factory tank do not look nearly as dependable for what I'm doing.
If you've got a tank designed for an in-tank pump, then of course it's better and cheaper. But for a factory tank, it's not so clear cut.
-'02 Dodge Viper Ex-World Challenge racecar
-'73 Duster, 6.1 based 392 hilborn hemi, tko600, full floater rear 9", Hellwig custom bars, viper brakes, built for road course
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: Uhcoog1]
#1613175
04/30/14 10:08 PM
04/30/14 10:08 PM
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Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Challenger 1
Too Many Posts
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Too Many Posts
Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
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Quote:
Quote:
Quote:
Quote:
Seems like the in-tank pump is the only real solution to this issue.
This is true, external electric fuel pumps are not the answer, no matter how tricked out it is.
Tell me why you believe this to be true.
Because there are too many heat sources to avoid externally, not really a good place on most cars to mount a external electric pump and have it gravity fed the whole time, harder to keep the sump covered when the line exits on one side of the tank verses a internal pump is in the center usually. The column of gas inside the tank helps create a positive inlet pressure for the internal pump. Which is also cooled by the gas in the tank.
There are more advantages to having it in the tank. Safety, cheaper, simpler and more. Good luck.
Have you run an in tank pump in a factory Mopar tank?
I chose the external pumps with accumulator because it's dependable for road course work, it keeps the fuel system out of the trunk, and it's fairly cheap. The options for an in-tank conversion for a factory tank do not look nearly as dependable for what I'm doing.
If you've got a tank designed for an in-tank pump, then of course it's better and cheaper. But for a factory tank, it's not so clear cut.
No I haven't ran it yet, but I have installed one recently, last month in a E body tank.
Check out aeromotive stealth pumps. I invested in the smaller pump at $440 bucks. Everything needed to install it is included including a sump.
I do have a lot of fuel experience, not just talking up this pump because I bought one.
For electric fuel pumps in our old cars, inside the tank makes so much sense. And is cheaper over all and will out perform most external pumps supplied by stock tanks even with sumps road racing.
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: Uhcoog1]
#1613179
04/30/14 11:06 PM
04/30/14 11:06 PM
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Joined: Feb 2011
Posts: 4,302
Nebraska
72Swinger
master
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master
Joined: Feb 2011
Posts: 4,302
Nebraska
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This is my surge tank, if I was building it today I would make it about half as big.
Mopar to the bone!!!
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: ahy]
#1613181
05/01/14 11:46 AM
05/01/14 11:46 AM
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Joined: Mar 2014
Posts: 40
upper So. CA
ntsqd
member
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member
Joined: Mar 2014
Posts: 40
upper So. CA
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I still want to know what the pressure going into the HP pump is during the worst case condition. If the filter is dropping the LP's output to near zero, then the HP will be pulling a vacuum in the line between the filter and it. Lowered pressure on the fuel plus a lot of heat plus winter fuel.....
Could be as simple as that filter is used up and needs to be replaced.
Would also be good to know what the pressure is in the line btwn the LP and the tank is during those conditions.
In 20 years of using Push-Lock/Barb-tite hose and fittings I've never seen that flapper happen, not even when using hose not designed for those fittings. Have seen it happen with generic fuel hose on generic barbed fittings. Condemning the whole system over a single failure is ludicrous.
I used to swerve around my hallucinations, now I drive right thru them.
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: ntsqd]
#1613182
05/01/14 12:02 PM
05/01/14 12:02 PM
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Joined: Feb 2011
Posts: 4,302
Nebraska
72Swinger
master
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master
Joined: Feb 2011
Posts: 4,302
Nebraska
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I didn't condemn the whole system, just the whole fuel system. Fast has switched vendors since this also. My main point here is check your lines, INTERNALLY, because to the naked eye they will appear normal.
Mopar to the bone!!!
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: Uhcoog1]
#1613183
05/01/14 12:30 PM
05/01/14 12:30 PM
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Joined: May 2005
Posts: 723
Houston Tx
Uhcoog1
OP
super stock
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OP
super stock
Joined: May 2005
Posts: 723
Houston Tx
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Quote:
More data.
Did a running test this morning. Outdoor temp was 55 degrees (vs 95 degrees at race where I had the issue).
Temps taken at 0 min, after 10 min warmup, after 10 min hard run (4k-6k in 2nd gear back and forth at full throttle and braking for 10 min).
Accumulator: 76.2. 89. 107(93 within 3 min of sitting)
Carter: 76.2. 94. 113.
Muffler: 76.6. 220. 404. (220 within 3 min of sitting)
Rear: 76.6. 103. 143.
Based on the data, I'm positive heat shielding between the muffler/rear end and fuel system will solve my issue.
Made some heat shielding with some thin sheet metal I had laying around and some leftover heat shielding tape.
Went out to do the same test as yesterday. Looks like I pushed it harder today and built more heat up. Muffler was 455 today vs. 404 yesterday, and it stayed hotter longer.
Here are the results:
Running test with heat shield. Repeat of yesterday. 55 degrees out at start. 0 min, 10 min warmup, 10 min hard running.
Accumulator: 73.0. 82.4. 105. Within 3 min- 97-98. Measuring side today vs bottom yesterday.
Wix: 73.5. 81. 95.
Muffler: 104. 260. 455. 3 min- 360.
Heat shield cover: 103. 270. 505.
Heat shield metal: 0. 107. 175.
Looks like a marginal improvement.
-'02 Dodge Viper Ex-World Challenge racecar
-'73 Duster, 6.1 based 392 hilborn hemi, tko600, full floater rear 9", Hellwig custom bars, viper brakes, built for road course
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: ntsqd]
#1613186
05/02/14 02:30 PM
05/02/14 02:30 PM
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Joined: Feb 2011
Posts: 4,302
Nebraska
72Swinger
master
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master
Joined: Feb 2011
Posts: 4,302
Nebraska
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Try having the high pressure pump suck straight from tank and measure temps. The heat is either coming from the pump or the biggest restrictions. Or the exhaust to I guess.
Mopar to the bone!!!
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: ntstlgl1970]
#1613188
05/08/14 10:15 PM
05/08/14 10:15 PM
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Joined: Mar 2014
Posts: 40
upper So. CA
ntsqd
member
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member
Joined: Mar 2014
Posts: 40
upper So. CA
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Curious that a MAP sensor isn't fluid tolerant given that it's ported to wet flow. I'm expecting there to be some degree of vacuum in the intended sampling spot, not pressure, but a MAP sensor that can read boost wouldn't be a bad call if that is the direction taken and I would suggest mimicking their normal mounting orientation. EDIT: Maybe just something like this? No point in over-thinking things. http://chucker54.stores.yahoo.net/vaprteki.html
Last edited by ntsqd; 05/10/14 01:16 PM.
I used to swerve around my hallucinations, now I drive right thru them.
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Re: Need help diagnosing fueling issue from Open Road Race
[Re: ntsqd]
#1613189
05/24/14 10:31 PM
05/24/14 10:31 PM
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Joined: May 2007
Posts: 553
Sac, CA, USA
ntstlgl1970
mopar
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mopar
Joined: May 2007
Posts: 553
Sac, CA, USA
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I had a combination of problems that contributed to the boiling issue, proximity of fuel system components to the exhaust and the fuel picking up so much heat from the engine. I spent a lot of time and money on insulating tape along with heat shielding around anything near a heat source but the car continued to boil the fuel. After I removed all of the external fuel system parts, I found something in the pre-supply pump inlet screen, some of the fuel tank sealer I had used in my tank came apart (after 5 years and ~4k miles)and was partially plugging the screen. The thing that was weird is that before I added the pre-supply pump, I had checked the pre filter in front of the main pump and it was clean. Maybe there was just enough of that stuff loose inside the tank that it would start restricting the outlet from the sump. Who knows. We were lucky to make it home. I bought a new stock tank intending to put an in tank pump in a boxed sump, but at this point I think I am going to forget the electric pump in a stock tank and get something from Rick's or Fuel Safe so I don't have to worry about this BS anymore.
Last edited by ntstlgl1970; 05/24/14 10:41 PM.
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