mx5cartalk.com

My NB8A track car runs the std pump, tank, fuel lines, etc.
For the last four years I have been able to run the tank almost down to vapours before it will (understandably) surge.

However last weekend at PI I had MASSIVE fuel surge in RH corners (pretty bad at Honda, horrific at MG, slight at Hayshed and Turn 1) with still over half a tank of fuel. LH corners were perfect, as was full throttle top gear down the straight, just RH corners. Which to me would rule out fuel filter, dud fuel, or crap in the tank, otherwise would be intermittent or inconsistent at best. This was 100% repeatable lap after lap.. and soooo frustrating..

Seeing as I never used to get it at all, I'm wondering what could have suddenly caused this issue?
Nothing has changed on the car at all since the last two meetings where it ran fine, except for the throttle body which I removed to clean and refitted. Cant imagine this is related cos as stated it drives perfectly in everything bar RH corners..

Ideas????

A loose earth / cable / vacuum hose / sensor connection etc etc that swings around on right hand turns only?

Could be...
I've got the wiring diagrams for my car. I might run around and check all the grounds to start with..

cheers

Has there been an increase in power which inherantly results in the engine using more fuel than it used to?

Just make absolutely sure you have a standard pump and sock because thats what I thought I had but when I had taken a peak into the fuel tank what I found was an aftermarket pump and sock and was having the same issue.

lightyear wrote:Has there been an increase in power which inherantly results in the engine using more fuel than it used to?

well, full throttle in top gear down the straight is perfectly ok so the problem isn't any inability to keep up with the fuel requirements.
Its just on RH corners, prob 4500rpm and once straightened up is also ok and revs out to redline no issue.. LH corners at same revs have no issue.

D-Train wrote:Just make absolutely sure you have a standard pump and sock because thats what I thought I had but when I had taken a peak into the fuel tank what I found was an aftermarket pump and sock and was having the same issue.

I've pulled the pump out to check connections and it's std sock and pump.
Also its been the same setup for four years and its only started doing it so not related to incorrect parts.
Going to check fuel pressure to see if it is fuel related or electrical to help narrow it down..

why not just cable tie a can around it as a make shift surge tank and see if it sorts it?