Fuel starvation

#1

Fuel Starvation - does it start normally on a right hand turn or left hand turn?

#2

IIRC, right hand turns - usually with less than half a tank.

#3

+1 for long right hand turns. Roebling turn 6-7 is a poster child.

#4

+2 for right handers. What year is your car? Have you replaced The pump(s) yet?

I have an 87 an replaced both pumps, been working fine ever since…until these burn out.:laugh:

#5

If you run your car completely out of fuel you can expect to start having starvation issues. Running out of fuel kills the pump. I ran mine out of gas and shortly after I had starvation issues at rockingham on the last turn and at mid-ohio on the last turn. Not sure what the deal was but they are both left hand turns. I replaced my in tank pump and haven’t had any problems.

#6

I was feeling the hesitation coming out of a long right hand turn but not in the turn. (coming out of T2 and getting ready for T3 at RRR).

The fuel level was slightly below the half way mark (although the fuel level gauge seems to want to change its mind whenever - sometimes a half way mark shows up as 1/4 full when I am coasting in to the paddock.)

Just curious as to where the pick up point was in the tank. Front of my car is 87-is and the back is 85-e.

#7

I was starving out at 3/4 of a tank before I replace all of the pumps, filters, and regulators. The in tank pump is cooled by the fuel. If you run it low very often it can shorten the life of the pump. We all look at them as wear items now.

#8

My car experiences fuel starvation during hard left turns at around the 1/2 tank mark. It’s fine above that. I can see the writing on the wall and have just ordered both the in-tank booster pump and the external main pump (my car is an '87). The fuel filter and all rubber lines around the tank are about 4 months old so I should be good there.

This seems to be a very common problem with these 20 year old BMWs.

#9

My '87 had it’s fuel pumps, filters, and lines replaced, but it still hiccups at a 1/2 tank after long right turns. So replacing the pumps isn’t a sure slam dunk.

#10

I’ve replaced literally everything fuel system related in the car and mine still stutters out after 4 -5 gallons (little more than 1/2 tank).

If you can replace a pump and have it work, count yourself lucky.

#11

Hmmm…

So it must be a fuel pickup issue, no?

#12

I am averaging about 12mpg. The hiccup seems to happen around 70-75 miles of track driving. So, that’s about 6 gallons down from full and about 50 minutes of hard driving.

So for a 3 hour enduro, it seems like it would require at least 3 refills. If you slow down may be on 2 fill ups.

What is the capacity of the tank? 12-14 gallons?

#13

Mine started doing it on Sunday at CMP. Most noticable coming out of turn 8.

John

#14

uh60fixer wrote:

[quote]Hmmm…

So it must be a fuel pickup issue, no?[/quote]

This issue has aggravated smarter folks then I. That makes me hesitant to conclude anything for certain. Maybe God just likes fuel cells.

#15

Anybody in a later model year have issues or is it just the earlier cars?

#16

During the enduro at VIR this weekend, we had starvation but only when it got down to about 2 gallons left in the tank. And I was using third gear in Hogpen, doing everything I could to keep up with James Clay. After it started missing, I only used forth, which reduced the starvation about 50%, and until we did the pitstop.

When I built the car, I had starvation at the 1/2 full mark but replacing the in-tank pump on my '89 fixed it. Evidently, I was one of the lucky ones.

  1. Bentley says the later cars have a 16.6 gallon tank. Does anyone know if this is correct?

  2. At VIR, JP brought up the idea of an update/backdate rule on the tanks so no one has an advantage in enduros. While we are trying to keep the rules stable for now, I certainly don’t want certain cars to have an advantage like this. We are doing more enduros now so it needs to be addressed.

Thoughts from the group?

Carter

#17

Five minute required stop for gas and or driver change should resolve that problem.

#18

Update or back date to any part that was used on an e30 that the owner feels is a better design.

So, if you want to go to all the trouble of putting '91 bumpers on a '84 car…well knock yourself out. Same for the bigger capacity fuel tank.Keeps the rules simple and allows the racers the option of moving to the “best” of e30 design. Keeps the rules guy from having to be in the middle of trivial discussions on bumpers and trunk lights.

I’m partial to big bumpers and the dual fuel pump set-up of the older cars.So I wouldn’t want to change, but would have no complaint/basis with someone that did.

Regards, Robert Patton

#19

I’m for allowing the mixing and matching of the early and late parts and pieces. But as Patton said… it shouldn’t be forced. There should be a maximum prep. Anyone who wants to be “under-prepared” should be allowed to keep the car as it is.

After all… you don’t want to have everyone on the front row.

#20

What about fuel cells? I know the stock location, etc etc.

I’ve replaced literally every fuel related component in my including the tank. It is a 90 IS, one in tank pump. I’ve added a second pump as well, didn’t help.

Still starve out after about 4-5 gallons (45 min.). In the enduros I’m toast. I did 4 pits stops w/ fuel when everyone else did one.

My options at this point, build a new car, or try out a fuel cell. I’m going to the cell.

I have a 12 gal. well cell, the easiest way to go. However I’ve been sent to the CCR 15.4 for fuel cell rules.

Basically they say - no minimum. So theoretically (if I’m reading right) I could add a 22 gal cell and drive forever?

Carter - what are your thoughts on this since I want to stay legal and not have to do rework, at least here since it is $$$$.