Thread: sr20ve rich idle only when warm.

i've been hunting down an small annoying issue with my classic. First i noticed my gas mileage was bad only like 25ish mpg mixed. So i did all the basics. Plugs checked cap and rotor. Replaced the dizzy as it was leaking oil. Then i found out the maf was bad so i got another one which is in spec per dc scotty's threads. Last month i redid the main engine harness getting rid of the emissions plugs i don't have and fixing some broken wires.

So know the car runs great. Getting about 33 mpg now. But after a long drive when the car is nice and hot the wideband starts showing like 10-12 afr at idle. Any other time after the intial warm up it's 14-15afr. What gives?

Now i had a code 34 for the knock sensor. Replaced it today expecting for the rich condition at idle to go away. i know the sensor was bad cause it was all rust cracked. But it didn't, the code went away, but the issue still persists.

no codes and you can tell a diffirence when it goes dumb rich. it has the alfred bin with an n60 maf lynchs bin.

only thing i can think of is the stock o2 sensor is going up. I need to upgrade to a 15727 anyway cause of the header.

please help need some sugestions.

cars mods are:
calum basic alfred lynch less timing bibn with n60 maf
thermo spacers
ssac 2.5 header
2.36-2.5 exhaust
3 inch intake
volocity stack and 6 inch filter
Aem for the wideband

Check that coolant temp sensor. The larger two prong one

I didn't think about that as an option.

but wouldn't the fans be acting up? and i read a thread on a sr swaped 240 and on those it's common for the harness to the cts to be bad.

Faulty Coolant temp sensors can cause havoc!

What is your MAF voltage at idle when your AFR is reading very rich ?

haven't checked that. but i did redo the maf wiring and found an almost broken wire at the ignition coil, where my msd is installed. but no change in the issue. Runs much smoother with the repaired wire.

The reason i ask is very important. If MAF voltage goes below 1.000v at idle the car will assume an AFM fault (but NOT register a code) and go into a kind of 'limp' mode and go very rich.

hmm. i need to check that. but i just got a old/new maf. that reads 1.2 at idle normally. it would suck if it's allready bad.

the car does't go crazy like it did when the other maf went bad. it would run rich but have a hard time driving at slow speeds and constantly bucking.