How to get through to leaner times!

[Guest jjohart]

Hi, I've whitewashed this board over the years with a 83 280ZXT which was running lean,, and the final, simplest band aid fix was to tie the oxy sensor to ground. I was happy for the car's performance, but I put on an air/fuel gauge (S7), and naturally, what everyone told me is the case...that the car is running rich (unless, of course, the oxy sensor is wrong, but that was the first thing replaced!). My guess is somehow the additional intercooler plumbing and CAI made the car run leaner, but this is academic, since I LIKE THE WAY THE CAR RUNS, and the old adage "if it ain't broke, don't fix it!" must apply.

That said, can anyone tell me of any relatively simple tricks to making the car run a bit leaner, such as that potentiometer trick people sometimes use on the exhaust temp sensor (to make it run richer, alas that didn't work for me either!). Please keep it simple (I'd prefer splicing a wire and adding a standard electronics part to opening up the AFM).

Then again, maybe the sensor and or gauge is messed up...seems a bit blingy...the display disappears when the car's turned off...wowee! I am putting on a fuel pressure gauge (sorry, not wideband!), so would adjusting my Bosch AFPR make the car leaner or cause other trouble?

It was set for 37psi.

Thanks to MLK and everyone wanting peace-perhaps not in this lifetime though...

[AK-Z]

You can try running smaller injectors. The ecu doesn't use them to monitor anything so its hsould behave normally, but if the ecu is getting the primary numbers for calc fuel from the o2 sensor then changing the injectors won't make a difference.

 

But most likely the ecu it running in "limp mode." Its a mode that the ecu goes in if if certain sensors are unable to be read or are giving a undesired value. The mode has pre-set values to be able to run the engine without causing and failures (such as pinging) which is why your car is running rich. Most people like to run the car like that and works fine with no problems, but they all run pig rich. So if the car is running in this mode then I say get smaller injectors and see if it runs a little leaner.

[nienberg.11]

Please keep it simple (I'd prefer splicing a wire and adding a standard electronics part to opening up the AFM.

 

Have you messed with the afm yet? It's really simple, and is a great way to alter your AFRs. Jersey made a thread about how to do it complete with step by step pics.