First off, thank you for the bother of signing up to ask a question. I'm stuck and my mechanics are stuck and I can't find anything with searching the Googles.


Problem -

The fuel-low lamp is on despite the tank being 1/2 full

In-tank sender functions properly - I added 20 litres and the gauge went up accordingly

The car drives well under normal circumstances, but will not boost properly when flooring it. It will cut (fuel or spark) at around 4000 rpm, then allow it back in cycles that will violently shake the car. If part-throttle, I can rev to redline with no problem.

When the car is doing this, the fuel-low light will flicker. When not boosting there is no flicker.


Car info -

1994 FD RX-7 Type RII Bathurst

Original Japan vehicle (in Japan using Japanese fuel)

48,000 km

All boost system solenoids were replaced by the mechanic with no change to the problem.

New fuel was used for the test, but due to low mileage, fuel system blockage is possible.


More details -

I have driven about 50+ RX-7s. I've noticed in the FC and FD that when the fuel is around the E-mark, these cars tend to surge when boosting. Knowing nothing about these cars, I assumed this was a safety system that prevents the combustion from running lean by cutting spark when the fuel is at risk of running out.


It certainly seems like this "safety" feature is kicking in early and I wonder if the fuel low light is sending a signal to the computer to back off.

Does anyone with experience in this have any suggestions on what to test. I don't do the work myself but I want to give my mechanic an idea where to look next.


Thank you anyone that can help and sorry for the inconvenience.

 

the low fuel light is kind of odd, maybe something is bent?

for the bucking and surging, my FD did this, and it would be fine with a full tank and gradually get worse as you used fuel. it turned out to be a plugged charcoal canister. you might try that.

you should also check for codes, there are a bunch that will do fuel cut with boost. with a JDM car you need to plug an LED into the diagnostic box, there is no Check Engine Light

 

Thanks for the suggestion. It certainly seems like the charcoal canister is a potential target.
I'll also tell them about the error codes. I know the drill with that, thanks.