Fuel Starvation Problems
05-20-2006, 03:43 PM
#28
Originally Posted by alnielsen
I haven't had problems with LH corners. I do run into starvation on RH's when the tank is less than 1/2 tank. From the description on how the tank and pickup is designed, I don't understand how this could happen.
In LH..the fuel is pushed to the passenger side tank.........From there I don't know what is the biggest problem....either the suction transfer fronm that tank won't transfer fuel fast enough....or the pump runs out of fuel due to the high fuel requirements....then the venturi quits..and the transfer stops??
I am going to try the pump in the R side port and see if it fits.......if it does I'm going to try the 2 pump setup and see how it works. Worst case scenario I have a spare fuel pump
05-20-2006, 05:18 PM
#29
Just took out the pump and the cover on the passenger side.
Both sides are the same....so I'm going to order a pump and see what happens.
I have a track day next week...so I hope I get the pump in time to try it and see if it will work
Both sides are the same....so I'm going to order a pump and see what happens.
I have a track day next week...so I hope I get the pump in time to try it and see if it will work
06-10-2006, 11:28 PM
#32
OK...been working on this a bit today...
Got the fuel pump, and all the wiring bits...went to the wrecker for some OEM bits...the plug on a Protege tank is the same as ours.........makes it easier to get the plug
I wired the pump to the OEM pump circuit...and installed a switch in the console by the Accessory plug. I figured why have this on all the time when I only need it on the track.
I got looking at the tank from underneath and couldn't find an easy way to run a fuel line that didn't get too close to either the exaust or the drive shaft. They didn't leave a lot of room in there.
What I did find though was that the unibody has a large x-brace that is the major structural member that goe across just ahead of the fuel tanks. It has some 3/4" access holes in it...and it is open all the way across the car. End of a search for a place to run the fuel line. It's in it's own little armored tunnel
All it took was a few minutes with a fish tape and I was good to go.
Ran into a little snag though....didn't have enough high pressure fuel line to run it the car
Couldn't find any today either...so I guess I'm using the wifes car until Monday....she'll be impressed.
All I need to do now is install the fuel pump...and rig some type of pickup for the suction siphon in the Right hand tank that will still transfer fuel to the Left side when the pump is not on ( like OEM ) and re-wire the fuel level sensor in that side of the tank.
So far I'm into it for about $180... Just won't know if it will work....guess I won't know until I hit the first really fast LH corner
Got the fuel pump, and all the wiring bits...went to the wrecker for some OEM bits...the plug on a Protege tank is the same as ours.........makes it easier to get the plug
I wired the pump to the OEM pump circuit...and installed a switch in the console by the Accessory plug. I figured why have this on all the time when I only need it on the track.
I got looking at the tank from underneath and couldn't find an easy way to run a fuel line that didn't get too close to either the exaust or the drive shaft. They didn't leave a lot of room in there.
What I did find though was that the unibody has a large x-brace that is the major structural member that goe across just ahead of the fuel tanks. It has some 3/4" access holes in it...and it is open all the way across the car. End of a search for a place to run the fuel line. It's in it's own little armored tunnel
All it took was a few minutes with a fish tape and I was good to go.Ran into a little snag though....didn't have enough high pressure fuel line to run it the car
Couldn't find any today either...so I guess I'm using the wifes car until Monday....she'll be impressed.
All I need to do now is install the fuel pump...and rig some type of pickup for the suction siphon in the Right hand tank that will still transfer fuel to the Left side when the pump is not on ( like OEM ) and re-wire the fuel level sensor in that side of the tank.
So far I'm into it for about $180... Just won't know if it will work....guess I won't know until I hit the first really fast LH corner
06-13-2006, 08:42 AM
#33
Registered
Join Date: Aug 2004
Posts: 170
Likes: 0
Received 0 Likes
on
0 Posts
It can, and has been fixed with the addition of a small auxillary pump in the fuel tank. Speedsource's solution was for, at least when I contacted them, ".... track cars only..."
Speedsource also advised that their solution would cost you the use of the cars fuel gauge ~ but there's a work around for that.
I was at Heatland park last weekend to watch a couple of friends competing in the SCCA Spec Miata series and Mazda open wheel "platypus" cars. There were a couple of 3 or so Rx8 running in T3. I asked one of the Rx8 drivers if they did anything for the fuel starvation issue. Somewhat to my surprize, he said they weren't allowed under the SCCA rules to modify the fuel tanks, so ..... they just make sure to run with an extra 5-6 gallons minimum in the tank. My guess is T3 must set some minimum weight limit, and the any particular race , test or qulaifying session is never long enough to make drawing the tank down below 1/3rd an issue. I guess the extra 5 or so gallons that has to be carried in the tank is simply chalked up as "dead" weight (? @ 5x7=35#) needed to maintain minimum weight for the class. Go figure
Speedsource also advised that their solution would cost you the use of the cars fuel gauge ~ but there's a work around for that.
I was at Heatland park last weekend to watch a couple of friends competing in the SCCA Spec Miata series and Mazda open wheel "platypus" cars. There were a couple of 3 or so Rx8 running in T3. I asked one of the Rx8 drivers if they did anything for the fuel starvation issue. Somewhat to my surprize, he said they weren't allowed under the SCCA rules to modify the fuel tanks, so ..... they just make sure to run with an extra 5-6 gallons minimum in the tank. My guess is T3 must set some minimum weight limit, and the any particular race , test or qulaifying session is never long enough to make drawing the tank down below 1/3rd an issue. I guess the extra 5 or so gallons that has to be carried in the tank is simply chalked up as "dead" weight (? @ 5x7=35#) needed to maintain minimum weight for the class. Go figure
06-17-2006, 02:24 PM
#34
I completed the install today.....no leaks, the fuel guage works and the fuel pressure stays basically the same with both pumps on For all intentions..the install looks totally stock. A casual observer would not be able to tell that this is done. The mechanics at the dealership came out to look and didn't notice until I pointed it out.
I won't know how it works on the track...but it will have twice the reserve capacity( two pumps, with the small surge built in) and twice the pump output capacity.
There will be no problems supplying more than enough fuel to max out the 5/16 stock fuel lines
I figure that all in all it cost me about $200 to do this. The pump was $160, and the other assorted bits from the wreckers,switch, wire, HP fuel line (4 ft) and hose clamps was less than $40.
I hope this solves my problem......next dry track day will tell
For all intentions..the install looks totally stock. A casual observer would not be able to tell that this is done. The mechanics at the dealership came out to look and didn't notice until I pointed it out.I won't know how it works on the track...but it will have twice the reserve capacity( two pumps, with the small surge built in) and twice the pump output capacity.
There will be no problems supplying more than enough fuel to max out the 5/16 stock fuel lines
I figure that all in all it cost me about $200 to do this. The pump was $160, and the other assorted bits from the wreckers,switch, wire, HP fuel line (4 ft) and hose clamps was less than $40.
I hope this solves my problem......next dry track day will tell
06-17-2006, 10:41 PM
#36
Originally Posted by dannobre
I completed the install today.....no leaks, the fuel guage works and the fuel pressure stays basically the same with both pumps on For all intentions..the install looks totally stock. A casual observer would not be able to tell that this is done. The mechanics at the dealership came out to look and didn't notice until I pointed it out.
I won't know how it works on the track...but it will have twice the reserve capacity( two pumps, with the small surge built in) and twice the pump output capacity.
There will be no problems supplying more than enough fuel to max out the 5/16 stock fuel lines
I figure that all in all it cost me about $200 to do this. The pump was $160, and the other assorted bits from the wreckers,switch, wire, HP fuel line (4 ft) and hose clamps was less than $40.
I hope this solves my problem......next dry track day will tell
For all intentions..the install looks totally stock. A casual observer would not be able to tell that this is done. The mechanics at the dealership came out to look and didn't notice until I pointed it out.I won't know how it works on the track...but it will have twice the reserve capacity( two pumps, with the small surge built in) and twice the pump output capacity.
There will be no problems supplying more than enough fuel to max out the 5/16 stock fuel lines
I figure that all in all it cost me about $200 to do this. The pump was $160, and the other assorted bits from the wreckers,switch, wire, HP fuel line (4 ft) and hose clamps was less than $40.
I hope this solves my problem......next dry track day will tell
beers
06-19-2006, 11:40 AM
#37
Registered
Join Date: Jan 2005
Posts: 86
Likes: 0
Received 0 Likes
on
0 Posts
I just came across this thread and wanted to give a bit of warning with the fuel system setup that you have currently installed (assuming I understand what you did correctly).
How exactly is the 2nd OEM pump plumbed into the fuel circuit? Do you have both pumps feeding to a T-joint on the outside of the tank and then to then feeding the engine? If this is the case I would advise against this.
This would work providing that both sides of the tank drain at the same rate and there was no sloshing of fuel from side to side. We know this isn't the case. If it were we wouldn't be seeing a starvation problems.
Knowing that during cornering we do not have any fuel in one side of the tank we know that the pump will not be picking up fuel on that side. If this is the case the pump will burn up fairly quickly. The carbon commutator and brushes of the pump need the fuel flowing past them to provide lubrication and cooling. Without any fuel present the pump will get very hot and seize. The pump will no longer work and you may have caused more starvation problems then before. Not to mention the fact that a large heat source is now inside your fuel tank.
If you are going to run 2 pumps in the tank. Hook the pump up to some type of logic so that the pump will shut off when there is no fuel present. This can be done by tapping off of the sender gage. I have seen it done before but not sure about the details.
Another option is to put a diaphragm type pump on the secondary side (passenger side of the tank). Diaphragm pumps can run full time without generating lots of heat and burning up. The diaphragm pump is not intended to supply the engine with fuel directly. It would only be present on the secondary side of the tank to transfer fuel to the reservoir on the main side. This would aid the venturi system that is already in place.
Sorry for the long post. Hopefully it helps. I don't post much but you guys finally have a problem that I can help with and I thought I add what I could.
How exactly is the 2nd OEM pump plumbed into the fuel circuit? Do you have both pumps feeding to a T-joint on the outside of the tank and then to then feeding the engine? If this is the case I would advise against this.
This would work providing that both sides of the tank drain at the same rate and there was no sloshing of fuel from side to side. We know this isn't the case. If it were we wouldn't be seeing a starvation problems.
Knowing that during cornering we do not have any fuel in one side of the tank we know that the pump will not be picking up fuel on that side. If this is the case the pump will burn up fairly quickly. The carbon commutator and brushes of the pump need the fuel flowing past them to provide lubrication and cooling. Without any fuel present the pump will get very hot and seize. The pump will no longer work and you may have caused more starvation problems then before. Not to mention the fact that a large heat source is now inside your fuel tank.
If you are going to run 2 pumps in the tank. Hook the pump up to some type of logic so that the pump will shut off when there is no fuel present. This can be done by tapping off of the sender gage. I have seen it done before but not sure about the details.
Another option is to put a diaphragm type pump on the secondary side (passenger side of the tank). Diaphragm pumps can run full time without generating lots of heat and burning up. The diaphragm pump is not intended to supply the engine with fuel directly. It would only be present on the secondary side of the tank to transfer fuel to the reservoir on the main side. This would aid the venturi system that is already in place.
Sorry for the long post. Hopefully it helps. I don't post much but you guys finally have a problem that I can help with and I thought I add what I could.
06-19-2006, 07:25 PM
#38
Thanks for the feedback. I have put a switch on the circuit...and only plan on running the pumps at the track when there is above 1/3 tank of fuel... I left the OEM siphon in place for emptying the passenger side of the tank like normal when the second pump is off. I will see how this works long term. I am aware of the problem with the pump running dry and overheating
06-19-2006, 07:59 PM
#39
I too have had this problem on high G LH turns. Once I had my suspension and R compunds on and the G's went straight up. In turn 5 at roebling -if I am in 3nd gear at 7.5--8K at the apex she flat dies, like you have turned the ignition off, and it lasts to the exit IF I AM AT FULL THROTTLE only. If I take it in 4th--rpms at 6K or so-- even at full throttle--no issues at all. (i was just experimenting --it is a faster turn for me in 4th than in 3nd). Still this is of concern. If the car is at high rpm and runs out of gas--it doesnt do this engine any good(I am also running a pre mix-- still have the MOP). this is the only place i have had a problem
olddragger
olddragger
06-19-2006, 08:05 PM
#40
Mine didn't do it either till I got the wide *** sticky tires
It wasn't a problem at all on the stock setup...just didn't pull enough G's in the corners
The thing i don't like is that the cut off is so fast that it makes the rear end break out......not a nice thing in a long 90MPH sweeper going into a blind apex corner that is a cement wall
I hope this will work...time will tell
It wasn't a problem at all on the stock setup...just didn't pull enough G's in the corners
The thing i don't like is that the cut off is so fast that it makes the rear end break out......not a nice thing in a long 90MPH sweeper going into a blind apex corner that is a cement wall
I hope this will work...time will tell
06-19-2006, 08:23 PM
#41
loose rear end does cause a lot of memories------ But you are right it is a sudden cut off , no skip, hiccup or anything--just DEAD and then it is all the way back ON when it comes back. You would swear it is somehow an ignition thing rather than a fuel problem--weird.
But we are hauling ***---right!
OD
But you are right it is a sudden cut off , no skip, hiccup or anything--just DEAD and then it is all the way back ON when it comes back. You would swear it is somehow an ignition thing rather than a fuel problem--weird.But we are hauling ***---right!
OD
06-19-2006, 08:33 PM
#42
Does yours set a missfire CEL....mine does....( second time around ) and then it doesn't want to run normal until I reset the ECU. It was so bad on the last dry track day that I had to stop driving part way through the last run group of the day... That really pised me off..
) and then it doesn't want to run normal until I reset the ECU. It was so bad on the last dry track day that I had to stop driving part way through the last run group of the day... That really pised me off..
06-19-2006, 09:05 PM
#43
man-- nope mine doesnt throw a code, no cel--just about a 30-40 yard complete loss of power. Really made my passengers eyes open up and grab the Oh S--- handle!!I think HE threw a code. You may need to gear down and use a lower final drive that brings the rpms down?--more dialed in? Just guessing here. Are you over 7K or so when this happens?
Olddragger
Olddragger
06-20-2006, 12:28 AM
#45
It is usually 7-8K at about 80 MPH in a long sweeper. just before you need to upshift to a higher gear. I have tried shifting earlier...but it doesn't have any power then and I loose a lot of speed in the corner.
The instructor almost had a coronary as well when it happened the last time......... just caught the *** end as it stared to come around
The instructor almost had a coronary as well when it happened the last time......... just caught the *** end as it stared to come around
06-20-2006, 09:39 AM
#47
Scaring them is one thing...I had one throw up in a full face helmet at one track day.
I registered late and they put me in a beginners group.....the instructor lost it in a corner
.
Got most of it on his suit.....but he was gone for the rest of the day
They moved me up to a faster run group after that.................without an instructor
I registered late and they put me in a beginners group.....the instructor lost it in a corner
.Got most of it on his suit.....but he was gone for the rest of the day
They moved me up to a faster run group after that.................without an instructor
06-20-2006, 10:35 AM
#48
lol--bet he remembers you. Swoope anyway to go to 17's 40 series r's or 18 --35 series r's on your car so you can possibily go into the turns and exit the turns in 4th? My car behaves the same way full power on 3nd at 7.5-8k(things are happeing fast then--not really watching the tac that much) in 4th --no problem and it ended up being faster for me. Cant go faster until you can upshift!
olddragger
olddragger
11-20-2006, 10:10 AM
#49
I miss my 'Bu
Join Date: Jul 2004
Location: GA
Posts: 1,243
Likes: 0
Received 0 Likes
on
0 Posts
I have started suffering from this issue too. I am on RT615s and expereince it starting even with a full tank. It happened out of the blue on a track I had been to before with zero problems so I am concerned it is a problem that gets worse with time.
Dannobre - I would like to get more details on your solution. Can I contact you? you can PM me if possible...
Anyone else try anything? Is it possible teh stock pump gets weak? My car has 48K on it now. Maybe just a new OEM pump fixes the problem for the next 40K miles?
Dannobre - I would like to get more details on your solution. Can I contact you? you can PM me if possible...
Anyone else try anything? Is it possible teh stock pump gets weak? My car has 48K on it now. Maybe just a new OEM pump fixes the problem for the next 40K miles?
11-20-2006, 07:13 PM
#50
I would change out the OEM pump...it's a relatively cheap thing to try , and it will probably work. The second pump on mine is only needed below 1/4 tank...I would probably not have done it If the new stock OEM pump would have gone in before all the rest of the stuff