What's up with this A/F reading?

What's up with this A/F reading? - 10/09/11 09:15 PM

I know I don't have any "real" data yet, but why would one side be so far off of the other side? I am reading from the same point on each side of the engine and am getting readings (just idle and intermediate so far) that are 5 whole numbers different from side to side. Any idea where i should start looking? Something obstructed in the carb? Air bleed plugged? Just looking for any thoughts from anyone that has gone thru this.

Posted By: MR_P_BODY

Re: What's up with this A/F reading? - 10/09/11 09:35 PM

First make sure the headers are tight

Posted By: sixpackgut

Re: What's up with this A/F reading? - 10/09/11 09:47 PM

misfiring cylinder

Posted By: bigtimeauto

Re: What's up with this A/F reading? - 10/09/11 10:18 PM

swap the sensors side to side before doing anything drastic

Posted By: Cab_Burge

Re: What's up with this A/F reading? - 10/09/11 11:45 PM

Quote:

swap the sensors side to side before doing anything drastic

Waht intake and carb are you running?

Posted By: 408strokerdart

Re: What's up with this A/F reading? - 10/10/11 01:43 AM

Quote:

Quote:

swap the sensors side to side before doing anything drastic

Waht intake and carb are you running?

Quickfuel 1050 dominator on a 598 casting chapman ported intake.

I kept the sensor with the controller it was calibrated for straight from Racepak. I can swap sides and re-check though.

All valid points to check before tearing into anything. I will hit the exhaust tubes with the infra-red gun to check for mis-fire. Engine sounds to good to be to far out of whack.

Keep the ideas coming though. Thanks.

Posted By: mr2performance

Re: What's up with this A/F reading? - 10/10/11 03:08 AM

What's it look like going down the track. If it has open headers you'll have a tough time making sense of anything except wot. Mike

Posted By: 440Jim

Re: What's up with this A/F reading? - 10/10/11 03:37 AM

Where exactly are your sensors located, and exhaust system configuration?
What are the actual readings?
What fuel are you running? gas, methanol, E85, natural gas (methane), etc.
You said 5 numbers, do you mean 13.0 and 8.0 AFR?

Posted By: nz383man

Re: What's up with this A/F reading? - 10/10/11 10:44 AM

Quote:

What's it look like going down the track. If it has open headers you'll have a tough time making sense of anything except wot. Mike

To get a good reading at lower RPMs you need the sensors 10 times the diameter of the pipe from the outlet, thats 35" foward of the outlet if you have 3.5" pipes. You would be amazed how much reversion you can get with big pipes at low speed.

Posted By: 408strokerdart

Re: What's up with this A/F reading? - 10/10/11 04:20 PM

Will get some WOT graphs asap. I understand that they are the most important on a drag car. This is on C14 fuel, dynotech merge collectors with the sensors in the top of the collector just past the merge. 4" open collector, about 10-12" past the sensor. Sensors are Racepak/bosch tied to a Sportsman data recorder thru individual O2 controllers.

Readings are 22.X on one side and 17.X on the other side. Bring the RPM up some and they come down to 17.X and 12.X respectively.