ka-t running rich

[Riubens]

Ok was up guys. Heres the problem ive notice that while am in crusing speeds my afr's are in the low 9 to 10 but at idle the car is at a steady 14.54 and WOT the afr's are a high 11's low 12's . so my question why could my afr's be so low(rich) while cruising??btw I have s-afc set -27 set across in LO and 23-26 across in HI,sensor type hotwire,5 in 5out .

things ive done to try to fix the problem:1)change temp sensor2)cleaned maf3)changed o2 sensor4)put new injectors orings5)recalibrated wideband6)changed sparkplugs and gaped them a 34 (runs fine)7)checked my timing is -2 all accros (to be safe)btw I have the intake temp sensor off the car (cant find it)

so does anybody have anymore suggestions ?,the car runs great so It might my wideband could be bad but am still open for ideas..sorry for the bad grammar english is not my first language.my set up is in my sig . except took out the 248 cam and went back to stock.forgot to add that I have an A/T ecu on my 5speed car and also the the engine is from an automatic 240 and it has one plug unpluged thats next to the throtle body cause my harness does not have that plug.

Modified by Riubens at 5:17 PM 3/15/2007
Modified by Riubens at 5:25 PM 3/15/2007

[eazye2000]

I would say turn the fuel down more in the Low throttle range in which you are experiencing the high AFR's. ?

[Riubens]

ive even brought it down to -40 in low it just scares me that I have 370cc injectors and everybody else runs -27 LO with out running so rich.

[eazye2000]

Every car is different. Even with the same setups, it's going to differ. Climate, temperature, altitude, fuel pressure, etc.. You will have to trust the wideband, or else take it to a dyno and have it tuned.

[Edub1]

Idle should be 16:1 or greater - as lean as you can go without stalling.

[Riubens]

come on guys do you have anymore suggestions am running -50 all across in LO in my S-afc and cruising afr's are still 12-13 ,and I only have 370 cc sr20 injectors I dont know what could be causing this car to run so rich??

[S13FX]

What are your throttle settings at?

[Riubens]

10%low & 50% high

low setings are like this -50 all acros in the low ,and thats just to have 12-13 afr's wile crusing and 1000 rpm -24, 2000 rpm -25, 3000 rpm -24, 4000 -24 ..etc

[Riubens]

bump, anyone?

[Florida240sx]

STOP DRIVING!!!!!!!! Smell your oil see if it smells like gas....... sounds like you might have crushed/tore an o-ring.To find out which one unplug an injector and see if car runs better or worse

[Riubens]

tried that already when ever I unplugged one it would hesitate like it is suppose to . I am really bumped????

but I do remember the car was running a little rich when it was N/A,it would blow black smoke out the tailpipe when ever it sat at idle and I would step on the gas,could my FPR be bad,or is my AT ecu causing this ?ive checked all the vac lines no leaks?is there some special wires that am supposed to do to the car since my car is 5 speed and I swapped a AT engine into it???
Modified by Riubens at 5:19 AM 3/23/2007

[Riubens]

OK,update checked the ecu for codes and got the follwing results :code 41 which is intake air temp sensor which I have disconected, code:76 which is fuel injection system funtion, and code:84 which is A/T diagnosis communication line.

am sure the injectors are in good shape and not leaking.

man this sucks!!!!

[Abdo]

your best bet would be to go to the salvage yard and pick out a manual ecu, see if that solves anything. the wire that is unplugged near your throttlebody also could be a problem (only because you're running an auto ecu and harness, otherwise it would plug in somewhere i suppose.), so changing to a manual ecu should fix the problem.

[Edub1]

Did you try plugging the IAT sensor back in?

[Riubens]

yeap put the iat back inn,changed the MAF sensor and changed the ECU to another A/T ecu because my friend couldn't find my 5speed ecu,car runs better.but it still runs rich after the car has run 15 minutes or so, and this new ecu is giving a new code which is code 77(rear 02 sensor) and 84(A/T communication line).what gets me mad is that when the car is cold I have the s-afc -27 across and the afr's are perfect but after the 15 minutes I have to change the LO settings in the s-afc to -40 from 2000rpms forward to get a decent afr ratio while cruising!

so could the rear 02 sensor cause this?? I thought it was for on board diagnosis only. if so could I plug it with the analog out of my wideband cause am not sure it will work for the rear o2 sensor, any inputs on this???

and also would the A/T communication cause this ?? I though this was basically the the speed governor?? or am wrong! any inputs on this also??

thanks you guy's.

[Abdo]

yeap put the iat back inn,changed the MAF sensor and changed the ECU to another A/T ecu because my friend couldn't find my 5speed ecu,car runs better.but it still runs rich after the car has run 15 minutes or so, and this new ecu is giving a new code which is code 77(rear 02 sensor) and 84(A/T communication line).what gets me mad is that when the car is cold I have the s-afc -27 across and the afr's are perfect but after the 15 minutes I have to change the LO settings in the s-afc to -40 from 2000rpms forward to get a decent afr ratio while cruising!

so could the rear 02 sensor cause this?? I thought it was for on board diagnosis only. if so could I plug it with the analog out of my wideband cause am not sure it will work for the rear o2 sensor, any inputs on this???

and also would the A/T communication cause this ?? I though this was basically the the speed governor?? or am wrong! any inputs on this also??

thanks you guy's.

Aha, it's weird that your old A/T ecu wasn't picking up that code 77.. Good job on replacing it though..I am almost certain that you're having an O2 sensor problem (most likely with the rear O2 sensor since you're getting that code 77). Oxygen sensors are required to perform a critical function on your vehicle in the harshest of environments: Measuring the oxygen content of the exhaust just after it leaves the cylinders. The oxygen sensor has to accurately check this hot exhaust hundreds of times per minute and send that data to the vehicle computer. The fuel/air mixture "hangs" in the balance, and the symptoms of a bad oxygen sensor: Black smoke from the exhaust, a rotten-egg odor, and poor performance and fuel mileage are exactly what you’re experiencing, right? A new oxygen sensor should fix the problem.

[Edub1]

Your rear O2 sensor is there to determine how well your cat is working. I'm not sure what problems it can cause but I'd replace it. If your car runs well in open loop but poorly in closed loop it might just be that sensor.

[Abdo]

Your rear O2 sensor is there to determine how well your cat is working. I'm not sure what problems it can cause but I'd replace it. If your car runs well in open loop but poorly in closed loop it might just be that sensor.

Thanks for pointing that out Edub1, what I said holds true for the front O2 sensor, so it might not necessarily be your rear O2 sensor making problems(don't cite me on that), perhaps it could be the cat (clogged maybe? sending weird signals to the rear O2 sensor which causes the car to run rich - don't cite me on that either ). Personally, I'de replace the rear O2 sensor first.

[Riubens]

thanks guys for your responses, I ve already changed the front 02 sensor and I dont have any CAT in the car I do have my rear o2 sensor unplugged because I dont have a bung for it and I lost the rear O2 sensor, so could I run one of my analog out lines from the wideband to my rear o2 sensor plug?

[Alsontime]

I have a similar problem with my s13 ka-t. After changing everything that I though could possibly be causing the problem (o2 sensor, etc.) turns out adding a few extra grounds to the motor smoothed out the problem. Just a thought...

[Edub1]

How close is your MAF to your turbo?