Fuel Starvation Problems
11-21-2006, 10:22 AM
#51
one thing to keep in mind, and this is where it gets confusing to me, with increasing options of mods giving honest increase in power plus R compunds,Plus suspensions,plus drivers getting better--all equals to the need for a stronger fuel delivery system. Once experienced this is an issue I dont ever want again--can be real dangerous on the track.
So which will it be:
1- Replacing the stock pump may solve this problem for a limited time and if no more mods happen to the car etc. cost approx $180-200?
2- go with Mazsports plug and play mod and have no worries up to 400hp--cost approx $400 after core rebate. approx $200 more for no more worries at all.
3- go with a Dannobre oridginal remedy and also it seems no more worries--cost unk but probably less than Scott's.
HMMMMM.
olddragger
So which will it be:
1- Replacing the stock pump may solve this problem for a limited time and if no more mods happen to the car etc. cost approx $180-200?
2- go with Mazsports plug and play mod and have no worries up to 400hp--cost approx $400 after core rebate. approx $200 more for no more worries at all.
3- go with a Dannobre oridginal remedy and also it seems no more worries--cost unk but probably less than Scott's.
HMMMMM.
olddragger
11-21-2006, 08:03 PM
#52
Scott's is $599 plus a refundable core charge.
It might not be the best for a NA car without tuning...as it uses a rising rate pressure regulator. The stock fuel system might not like the variation in FP when it doesn't expect it.
Changing the FP results in mixture changes.......Youi would have to ask Scott if it will work NA with the stock ECU. I'm sure it will work awesome with the IntX and some tuning
It might not be the best for a NA car without tuning...as it uses a rising rate pressure regulator. The stock fuel system might not like the variation in FP when it doesn't expect it.
Changing the FP results in mixture changes.......Youi would have to ask Scott if it will work NA with the stock ECU. I'm sure it will work awesome with the IntX and some tuning
11-22-2006, 09:17 PM
#53
I miss my 'Bu
Join Date: Jul 2004
Location: GA
Posts: 1,243
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by dannobre
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 
11-23-2006, 05:51 PM
#54
good point dannobre--i also realized after i point out that scotts mods really has not been proven to fix this issue. its more of an upgrade for fi.
After all is said and done --you know i am not totally convinced that my problem is fuel starvation. I mean with my pr0blem there is no hiccup, no skip, no sputter, the engine just dies as if the ignition turned off and then no sputter, no hiccup, no hesitation--she is back on full power. Same place on ONE track and I know I am pulling just as many G's in other left hander's. it is really very strange. Before I do anything radical here I have to do more research.
olddragger
After all is said and done --you know i am not totally convinced that my problem is fuel starvation. I mean with my pr0blem there is no hiccup, no skip, no sputter, the engine just dies as if the ignition turned off and then no sputter, no hiccup, no hesitation--she is back on full power. Same place on ONE track and I know I am pulling just as many G's in other left hander's. it is really very strange. Before I do anything radical here I have to do more research.
olddragger
11-23-2006, 06:25 PM
#55
That's exactly what mine did...it just died...and then came back on after the G-load dropped.
Maybe the pump is cutting out?.....It stuttered sometimes as well on less severe corners, and acted more like fuel starvation normally does.
It would only do it on long sustained Lefts at first at 1/2 tank or below. After a while it got worse, and would do it when the tank was almost full.
The new pump fixed it down to about 1/4 tank...and with the second pump Iwas good to almost fumes before it would quit
Maybe the pump is cutting out?.....It stuttered sometimes as well on less severe corners, and acted more like fuel starvation normally does.
It would only do it on long sustained Lefts at first at 1/2 tank or below. After a while it got worse, and would do it when the tank was almost full.
The new pump fixed it down to about 1/4 tank...and with the second pump Iwas good to almost fumes before it would quit
11-23-2006, 06:41 PM
#56
thanks dannodre--good to know. Mines a little stranger as that is the only corner on any track i have ever had any issues with. even with a FULL tank of gas. The 1st lap was uneventful but from that point on well----
A simple T pickup one on passenger side --one on driver side wouldnt work?
olddragger
A simple T pickup one on passenger side --one on driver side wouldnt work?
olddragger
11-23-2006, 09:09 PM
#57
There is no real way to add a pickup tube that goes to both sides...esp with the stock setup.
The fuel level system uses 2 levers...and assumes that the passenger side tank is empty when calculating the level on the lower end of the tank from what i can see.
You will see how it works when you pull it out....the passenger tranfer is a siphon from a venturi that is driven by the fuel pressure regulator outfall.
The fuel level system uses 2 levers...and assumes that the passenger side tank is empty when calculating the level on the lower end of the tank from what i can see.
You will see how it works when you pull it out....the passenger tranfer is a siphon from a venturi that is driven by the fuel pressure regulator outfall.
11-25-2006, 09:36 AM
#59
Also remember the old dirt track and circle track boys used to build a "false mini surge tank" by putting the biggest dang tube they could find for the gas line--effetively adding in some extreme case 1 gal to their capacity. I would not want to go with that big of a line with an fuel injected car but I was wondering if you just added a bigger line would it not give you enough gas to get through our problem area and then the pump could catch up? Could that be a simple fix for us non regulated track guys?
I like your system--seems more solid than others i have read about--but not ready to go that complex route yet. I have to have a solid system --dont mention it(so I post about it--right) but I plan on going with the afsc and with that much on the engine i damn sure i dont want any lack of fuel.
thoughts?
Olddragger
I like your system--seems more solid than others i have read about--but not ready to go that complex route yet. I have to have a solid system --dont mention it(so I post about it--right
) but I plan on going with the afsc and with that much on the engine i damn sure i dont want any lack of fuel.thoughts?
Olddragger
11-25-2006, 10:16 AM
#60
that won't work or fuel injection without a second scavenger-type pump further up stream, once you lose fuel pressure you're done with EFI regardless of the tube size, the NASCAR engines use an engine-driven suction pump to feed an atmospheric carb bowl, what you need is a small reserve tank between the pump and the EFI with an auto air bleed devise, alternatively you could use a small secondary tank supplied by a low pressure pump which then serves as the feed for the high pressure pump but it gets complicated with an in-tank system
Last edited by TeamRX8; 11-25-2006 at 10:18 AM.
11-25-2006, 10:34 AM
#61
Bingo!---thanks team--i complety wasn't thinking of that. Pressure has to be there and if the pump aint sucking fuel --- there will not be any pressure---looks more and more like i too will be doing the bmw fix like Dannobre BUT using Mazsports set up as primary--why isnt anything easy for me---damn.
Appreciate the focus--thinking too hard of a way out.
olddragger
Appreciate the focus--thinking too hard of a way out.
olddragger
11-25-2006, 10:48 AM
#62
You will probably have to run the regulator different on Scotts...ie without the Vac presure adjustor attached??? The Fuel pressure is designed to rise in his setup when the manifold gets pressurized........
Duh...when I was typing this I answered my own question....no positive pressure = no rise in regulator output.....Double DUH for it being way too early on a Sat morning
Duh...when I was typing this I answered my own question....no positive pressure = no rise in regulator output.....Double DUH for it being way too early on a Sat morning
11-27-2006, 07:56 PM
#65
Would be hard to do I think.....Speedsource mods the tanks somehow i think.....but they make the fuel guage inoperative at the same time....might not be a problem that is hard to fix.
I can live with OK down to 1/8 tank......
I'm also not totally sure it's a slosh thing...it might have something to do with how the pump pickup works....It might run the "little cup" out of fuel...and be unable to refill it....you would have to look at your pump to figure that out I think why my 2X pump works is that it has twice the reservoir before the pumps run out of fuel??
I can live with OK down to 1/8 tank......
I'm also not totally sure it's a slosh thing...it might have something to do with how the pump pickup works....It might run the "little cup" out of fuel...and be unable to refill it....you would have to look at your pump to figure that out
I think why my 2X pump works is that it has twice the reservoir before the pumps run out of fuel??
11-28-2006, 08:13 AM
#66
Registered
Join Date: Aug 2004
Posts: 170
Likes: 0
Received 0 Likes
on
0 Posts
Speedsource won't guarantee the fuel gauge working after their mod. They also have said, at least in the past, they provide the modified tank for track cars/track use only. I can say with careful positioning of the parts, one can retain use of the fuel gauge. FWIW, I can now run the car on the track down to almost the reserve line without fuel starvation. Before, with MPSC and Dunlop SSR 255 and 265/35's x 18's I could, would and did have fuel starvation issues with as much as just under one-half a tank in the car. As fast as these cars chew up fuel on the track, i.e. I'm getting something like > 10 mpg under track, being able to confidently run the car without having to refuel every session is well worth the cost of getting this issue fixed. Having your car suddenly lose power or "surge" then lose all power in the middle of high speed sweepers, with other cars in close proximity to your rear bumper is not something to be enjoyed. It's a hazzard.
11-28-2006, 06:10 PM
#67
I concur--I am not tracking my car until this is fixed. It is very puzzleing. Deductive reasoning list
1: I ran the same track(Roebling) several times before and even let a certified driver take it out and had no issues--even at 1/2 a tank.
2- then a few months later another track w/e and sx's show--controllable by lowering the RPM and throttle position--same track--on the same turn --shown 1st when i had about 1/2 tank
3- i did another track even --this time at road atlanta--no issues even at below 1/2 tank. and we were running hard
4- back at roebling a few monthes later and after the 1st lap --even with a FULL tank on one particular turn(double apex left hander immediatly after a short r hander--i go a DEAD engine for about 50 yards as I am exiting the l hander---nothing i could do would stop this--lower rpm, partial throttle---nothing. But it didnt get any worst as the gas got lower in the tank( i contunied to run-- but when traffic was around i would wave them by)
Never have had this problem anywhere else.????????? So in my case it seems to be a progressive problem.
If it is a cup issue why that one spot when other left handers pull more G's and are even longer?
Since it is a double apex there it is a "sudden" change in direction therefore this made me think of the slosh possibility.
still researching this--scotts system may work because it does convert to a return type system and the pump is stronger. if anyone else has any experiences or solutions please join in.
dannobre your system is the only one i know of that fix's this!
saga continues
olddragger
1: I ran the same track(Roebling) several times before and even let a certified driver take it out and had no issues--even at 1/2 a tank.
2- then a few months later another track w/e and sx's show--controllable by lowering the RPM and throttle position--same track--on the same turn --shown 1st when i had about 1/2 tank
3- i did another track even --this time at road atlanta--no issues even at below 1/2 tank. and we were running hard
4- back at roebling a few monthes later and after the 1st lap --even with a FULL tank on one particular turn(double apex left hander immediatly after a short r hander--i go a DEAD engine for about 50 yards as I am exiting the l hander---nothing i could do would stop this--lower rpm, partial throttle---nothing. But it didnt get any worst as the gas got lower in the tank( i contunied to run-- but when traffic was around i would wave them by)
Never have had this problem anywhere else.????????? So in my case it seems to be a progressive problem.
If it is a cup issue why that one spot when other left handers pull more G's and are even longer?
Since it is a double apex there it is a "sudden" change in direction therefore this made me think of the slosh possibility.
still researching this--scotts system may work because it does convert to a return type system and the pump is stronger. if anyone else has any experiences or solutions please join in.
dannobre your system is the only one i know of that fix's this!
saga continues
olddragger
11-28-2006, 06:24 PM
#68
I would think that the stock pump is crapping out...that's about the same chain of events that mine had.....I thought at the time it was me going faster and pulling more G's..but I think it was the pump. You can solve it by putting in a surge tank....A tank that is inline...pressurized with another pump. That will solve it as well.
I would go with the new stock pump and I think that it will probably work.
I also think that the Mazsport pump should work as well.......but until one of us does it and tests it at the track...back to back with the non-working one, we won't be sure
I would go with the new stock pump and I think that it will probably work.
I also think that the Mazsport pump should work as well.......but until one of us does it and tests it at the track...back to back with the non-working one, we won't be sure
12-11-2006, 12:42 AM
#71
Registered User
Join Date: Nov 2005
Location: Melbourne, Australia
Posts: 337
Likes: 0
Received 0 Likes
on
0 Posts
I'd like to include myself in the "fuel starvation problems". LH high G corner had me thinking that I was already hitting the rev limiter. I looked at the revs and it was just showing 7k rpm. Bloody hell... it really sends the car into an imbalance especially when the car is in mid corner. Oh well... time to have the fuel system looked at or getting the fuel pump upgraded. FARK!!!
BTW fuel starvation problem showed up with just 3/4 fuel in the gauge.
BTW fuel starvation problem showed up with just 3/4 fuel in the gauge.
12-11-2006, 06:58 PM
#72
Hmmmmmm--- the more I read the more I think one could really get involved in a fuel delivery system.
Mazsports system is a really good system but I just dont have that amount laying around here at Christmas. And since I dont have FI that volumne of delivery and 1:1 regulator is not really required. It would be a bit overkill for me but for the FI guys its a great setup.
One thing about converting to a return type system is the likelyhood of throwing emissions based CEL's and I really don't want that but I may not have a choice if just a new pump doesnt solve the problem. By the way I won a new pump for $65 on e bay--gotta love it!
I have a freind working on a set up for me. We will see what turns out.
What I would like to have is like Dannobre's system with just a few more features.
that is a dual pump system--nonreturn---with impact/turnover safety features and a high speed only option(for track use only). The safety features may be available by taping into the stock fump pump wiring harness and upping the 15 amp fuse to a 20 or 25. I dont know for sure that is why I am letting an expert think about it.
WHo knows---if we can get a practical low cost kit available--maybe we can even market it?
olddragger
Mazsports system is a really good system but I just dont have that amount laying around here at Christmas. And since I dont have FI that volumne of delivery and 1:1 regulator is not really required. It would be a bit overkill for me but for the FI guys its a great setup.
One thing about converting to a return type system is the likelyhood of throwing emissions based CEL's and I really don't want that but I may not have a choice if just a new pump doesnt solve the problem. By the way I won a new pump for $65 on e bay--gotta love it!
I have a freind working on a set up for me. We will see what turns out.
What I would like to have is like Dannobre's system with just a few more features.
that is a dual pump system--nonreturn---with impact/turnover safety features and a high speed only option(for track use only). The safety features may be available by taping into the stock fump pump wiring harness and upping the 15 amp fuse to a 20 or 25. I dont know for sure that is why I am letting an expert think about it.
WHo knows---if we can get a practical low cost kit available--maybe we can even market it?
olddragger
12-11-2006, 07:05 PM
#73
Originally Posted by olddragger
Hmmmmmm--- the more I read the more I think one could really get involved in a fuel delivery system.
Mazsports system is a really good system but I just dont have that amount laying around here at Christmas. And since I dont have FI that volumne of delivery and 1:1 regulator is not really required. It would be a bit overkill for me but for the FI guys its a great setup.
One thing about converting to a return type system is the likelyhood of throwing emissions based CEL's and I really don't want that but I may not have a choice if just a new pump doesnt solve the problem. By the way I won a new pump for $65 on e bay--gotta love it!
I have a freind working on a set up for me. We will see what turns out.
What I would like to have is like Dannobre's system with just a few more features.
that is a dual pump system--nonreturn---with impact/turnover safety features and a high speed only option(for track use only). The safety features may be available by taping into the stock fump pump wiring harness and upping the 15 amp fuse to a 20 or 25. I dont know for sure that is why I am letting an expert think about it.
WHo knows---if we can get a practical low cost kit available--maybe we can even market it?
olddragger
Mazsports system is a really good system but I just dont have that amount laying around here at Christmas. And since I dont have FI that volumne of delivery and 1:1 regulator is not really required. It would be a bit overkill for me but for the FI guys its a great setup.
One thing about converting to a return type system is the likelyhood of throwing emissions based CEL's and I really don't want that but I may not have a choice if just a new pump doesnt solve the problem. By the way I won a new pump for $65 on e bay--gotta love it!
I have a freind working on a set up for me. We will see what turns out.
What I would like to have is like Dannobre's system with just a few more features.
that is a dual pump system--nonreturn---with impact/turnover safety features and a high speed only option(for track use only). The safety features may be available by taping into the stock fump pump wiring harness and upping the 15 amp fuse to a 20 or 25. I dont know for sure that is why I am letting an expert think about it.
WHo knows---if we can get a practical low cost kit available--maybe we can even market it?
olddragger
beers
12-12-2006, 12:14 AM
#74
Mazports system isn't any more a return system than stock...from what I can see?? the stock system regulator dumps into the same position in the unit as the regulator in the upgrade. It has too to run the venturi. Thje big difference is the capacity of the pump...and the rising rate regulator when the car is in boost.
FYI OD..both pumps run on the stock wiring harness on mine...with the same fuse......never blown on me yet. both pumps will run at low speed...until the ECU says....go fast
FYI OD..both pumps run on the stock wiring harness on mine...with the same fuse......never blown on me yet. both pumps will run at low speed...until the ECU says....go fast
12-12-2006, 01:00 AM
#75
Registered User
Join Date: Nov 2005
Location: Melbourne, Australia
Posts: 337
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by olddragger
WHo knows---if we can get a practical low cost kit available--maybe we can even market it?
olddragger
olddragger