Sounds like a fuel delivery problem to me. How full is your tank when your doing these u-turns?

 

This morning (when it happened in U-Turn)... between 1/3rd & 1/2 full. Not an "empty tank" kinda thing for certain.

- Dave

 

Starvation is common for auto-xer and racers w/ less than 1/2 tank of gas.

I'd check your fuel system, espeically the pump and pickup.

 

 

Okay, I'll bite. In the event that the service tech at my dealership won't otherwise know, is there a recommendation to be offered on how to check the fuel pump and pickup? And (pardon my own ignorance here) are these 2 separate items to check out...or 2 parts of one item? Lastly...location of this/these? If I remember reading past posts, I think the fuel pump is housed in the fuel tank. Is it accessible?

krazik...an associated question if you don't mind: If you are suggesting above that "starvation is common for auto-xers and racers w/ less than 1/2 tank of gas", then are you also suggesting that (if they find nothing wrong with my fuel pump and pickup) what I'm experiencing is "normal" under such turning conditions and that I should not worry?

I guess I'll hope they *do* find something. Back where Reignman asked about The Dragon...we're talking about a stretch of road that has 318 turns in 11 miles. This past spring I had this problem present itself easily 20 separate times/turns...yet [roughly 40] other S2000s at the event never complained once. I could have a lemon I suppose...but I guess as you're pointing out, hopefully I have a problem with my fuel pump and/or pickup.

- Dave

 

When I used to work on cars, we would have cars present with the same problem. If the tank has a baffle around the fuel pump area, (don't know if ours does) they can come loose and when going around a corner with 1/2 tank or less, the pump would suck air. We replaced many tanks for this. Also, GM has fixed this on their cars by making the pump assembly hold about a pint of fuel to prevent this. Also, do our cars have an enertia switch for the fuel system that Ford used to use?

 

No what you are experiencing isn't normal because its not at high g's. You really need to rail on the car to get it to starve under "normal" conditons. Tho being that its happening on left turns follows what us speed junkies have found.

In a normally working tank starvation is a lot eaiser to achieve going left than right. But either way it usually takes race speeds and R compound tires.

 

On fresh S-02s the S2000 can pull some pretty good G's in a U-turn, and the known starvation most always occurs on accelerative left handers. In first gear in a U-turn both lateral and longitudinal g's are high.

Solution: run more gas in the tank. If it still does it with a full tank, then there is definitely something else wrong.

This problem appears to be worse on some cars than others. Joe Goeke was experiencing fuel starvation with 3 bars past half full at the Solo2 Nationals last year. We had to run over 3/4 tank to eliminate it. I've experienced it personally with 3/4 tank exiting turn 2 at Laguna Seca on slicks. I found that attempts to be exceedingly smooth would help somewhat, to help keep fuel from momentarily sloshing away from the pickup and causing a starve; a hard 1st gear U-turn is likely anything but smooth.

 

I'd say forget the banjo bolts. Just my opinion.

 

Okay...thought I'd post here with an update.

[I reserve the right to change my tune down the road ]

Fuel pump has been installed for 1 week now. Winter (aka rain, wet roads) have not allowed for too many "romps" for testing. However, I *HAVE* had a few chances to test the livin' heck outta this fuel pump now. Two scenarios come to mind (and that I've therefore tested to):

• Straightline @ 80mph in 6th, drop to 4th & run up to [near] redline on 5th and 6th at full throttle, and
  
• U-turns in 1st at near-full-throttle-to-full-throttle (near-full throt during turn; once on a straight line full throt.).

The straightline 80mph test I've done ~ 4 times now. ...no hesitation / cut out.

The U-turns test I've done ~ 10 times in a row now. ...no hesitation / cut out.

[Hate to jinx myself here......] Looks like the replacement of my fuel pump has, indeed, corrected this particular S2000's hesitation issue. Feels good and strong .

- Dave