Well I let my FC rest over our 2 hottest summer months here so I drove it maybe 2 times over December/January.
Now I've just got back to driving it regularly I've noticed my A/F gauge is reading that I'm running leaner than I was before. It's a autogauge a/f gauge, so it's not the most expensive and therefore accurate gauge but it does get the job done to an extent. The gauge reads something like this
--------
Green
Green
Orange
Orange
Red
Red
--------
The closer to the top, the richer it's running.

Now before I rested it, it would always be on the first green when warmed up under throttle or on idle, but lately it's been sitting on either the first or second orange, holding that under idle and during throttle up to rev limit.

Any suggestions or ideas on what I should look at, or that may be causing this??

I'm running a jap S5t with a chipped kinght sports ecu (better maps, fuel cuts etc)
, bigger fuel pump (walbro), high flow turbo, fmic and some other junk. Still running standard injectors.
I tried pulling the power to reset to ecu as I thought it may of been running a bad set of maps, but it's still running lean.

Thanks fo your help, gotta head to work but I'll have a look at any suggestions when I get back

 

Also thought it might be worth mentioning I don't premix and I ran the old fuel that was in there almost dry and have since topped up twice with new fuel

 

anyone have anything?

 

injector cleaner, some dry gas and change your fuel filter.

 

Don't know if this will work but it doesn't cost anything. So, it may be worth trying. Someone told me to disconnect the battery for about 20 minutes. The theory was that if you let the car sit for long periods of time the computer changes your fuel mixture. Disconnecting the battery resets things. This maybe complete crap, but it's worth a try.

 

Yup..you said 2 Hot months ..no runnin..I would be lookin at changin the fuel filter..the gas could have gone "bad"..and gooey ..doesn't matter if you ran some new stuff through..the CRAP is still there..if you have to park it again..use fuel stabilizer..and all according to the brand you use it will prevent the fuel from going Bad for up to six months..best to ya..

 

Fuel pump resistor circuit might not be switching properly.


-Ted

 

Going to change the fuel filter tomorrow and check the main sensors (vac, o2, tps) and maybe change the plugs while I'm at it

If it's still running lean after that I'll probably take out the injectors and get them cleaned and flow tested.


RETed: How do I check the fuel pump resistor circuit?

thanks guys

 

Monitor the voltage at the fuel pump.
It should be around 9.5VDC at low load, and full voltage (~13.0VDC) at boost.


-Ted

 

Well I changed the fuel filter today and took it for a quick squirt.
Seems to be running richer so i'm assuming the problem was infact from sediment forming in the fuel when it was resting. I'll probably run some injector cleaner through it later on this week and see if it helps anymore.

Oh and the fuel filter that was in there looks like it may be *fairly* old

 

Outside looks mean nothing. The only way to find out is cut it in half and take a look inside - like you do oil filters. ~rich