Fuel Starve
 

I'm trying to determine if I have a unique fuel starvation issue or if this is common to all RX8's before I tear into the fuel system on the car. Any input/experience would be appreciated.

- We have now had the problem on three different Solo courses this year with 180 degree or greater left hand turns including the Newport Pro event and a test-n-tune at Grissom this weekend. We determined that the car must have 3/4 of tank or more fuel onboard to prevent the fuel starve when accelerating away from the 180+ corner (occurs about 50 to 100 feet after the corner exit). It's consistent and gets worse with successive runs as the fuel load is reduced.

- The thing that really has us scratching our heads is, the car was run at 12 plus events last year plus a tire test which included skidpad work in the counter clockwise direction and no fuel starve was noticed running the fuel level down to 1/8th tank. The fuel starve appears to happen much sooner now?

- I realize it is common for the car to fuel starve once the low fuel light comes on and the pick-up is located in the lefthand saddle tank but I have not found any other instances of fuel starvation on the forum above 1/2 tank. The fuel gauge operation was also checked.

Any thoughts ?

Thanks-

Chris H
2006 RX8 Sport, Base Model

I never run anywhere near that much and have never had it

maybe a weak fuel pump or partially clogged internal fuel pump filter or bad pickup :dunno:

Thanks Mark -

That's pretty much where I'm at. It's just strange that if their was a flow restriction or a weak pump that the car would still perform well under full throttle for extended periods (Pro Solo Launch etc). The only time it occurs is following the hard, sustained lefthanders...
:pat:

We only had a problem if under 1/4 tank and long sweeping left.

^ Agreed,

You must be running a pretty hardcore tire/suspension setup to pull the kind of Gs needed for fuel starvation at 3/4 a tank.

Mine did it when the stock pump crapped out. Hasn't happened since the mazsport pump upgrade.

It got progressively higher in the tank...at first it was 1/4 tank..then 1/2...after a while it would do it at 3/4

I've always used the low fuel light as a "fuel starve indicator" when autocrossing, but I was suprised to find that I could fuel starve the car with about 1/3rd of a tank during long duration left hand turns at track days.

Yours still seems excessive Chris. I'd say it's time to call Mazdacomp and order a new fuel pump.

I have had it at 1/2 tank--replaced pump--no probs.
olddragger

Thanks everyone...sounds like a fuel pump R&R is in my near future.

Chris H

Check out the Mazsport fuel pump.

he has to stick with the OE pump due to class competition rules

be advised that you'll need a special factory tool to get the fastening flange that mounts the pump to the tank off and on, numerous threads on it for a search

Thanks...I found the thread with removal procedure, I'm going to give it a try without the specialty tool first. Hopefully, this is a one time repair.

Chris

be careful with the rubber gasket---its $50 to replace and make sure the pump doesnt turn when you are taking the top off.
its not hard to do.
after you get the old one out take it apart--you will be surprised.
see fuel starvation thread.
olddragger

Update - I installed a new, stock fuel pump sourced from the great guys at Mazdaspeed ($100 for Mazdaspeed members) a couple of weekends ago. Removing the plastic ring is a challenge without the factory tool, but once it's off, everything is very straight forward.

This weekend was the first opportunity I had, at a solo event, to see if the fuel starvation was corrected. With the fuel light just turned on, I am now able to make a 180 degree left turn again (at max g load) without starving out during WOT acceleration. :)

I can only assume that something internally in the pump malfunctioned or became restricted over the winter months.

Chris H

^ Awesome. Glad she's back in tip top shape Chris!

=( i wish i could be a mazdaspeed member so i can buy these pump at cheaper price XD...

i have the same problem, new pump below 3/4 of tank, my car starve

help!