Grounding issue?
Grounding issue? I taken my car to get tuned and dynoed around Harrisburg, PA, but I am having issues with multiple sensors. The voltages for MAP, MAF, an O2 sensors flucuate consistently while the key is in the run position but without starting the car. The tuner told me that it could possible be a grounding issue. I know there are supposed to be 3 grounds on the back on the heads but I have two onthe back of the driver side, and I think the 3rd was grounded off the bottom of the block for the driver side o2 sensors.
I did a diagnostic on the car with the diablo sport, three of the o2 sensors are flucuating around 420 to 450 mV, the 4th (Bank 1, Sensor 2) started off around 180 and bounced around and gone up to 285 when I stopped. The car was not started and only had the key in the run position.
I currently have a FastToys Air Lid, Lingenfelter 100 mm MAF, Fast 90/90, and work has been done to the heads, and changed out the pistons and connecting rods.
Any thoughts or suggestions would be greatly appreciated. I will also verify the information from the tuner.
I did a diagnostic on the car with the diablo sport, three of the o2 sensors are flucuating around 420 to 450 mV, the 4th (Bank 1, Sensor 2) started off around 180 and bounced around and gone up to 285 when I stopped. The car was not started and only had the key in the run position.
I currently have a FastToys Air Lid, Lingenfelter 100 mm MAF, Fast 90/90, and work has been done to the heads, and changed out the pistons and connecting rods.
Any thoughts or suggestions would be greatly appreciated. I will also verify the information from the tuner.
The voltage for the o2 sensors should move due to the heaters working. Normal. Unless the computer has them shut off. Depends on program. But that sounds normal.map an maf should stay. Check for 5 volt reference across conector.
After a few months of travel was able to have someone relook into the situation. the TPS had a break in the wire about 10 in from the sensor. Found out by pinning out the wires. Also the TB wasn't returning to zero, due to an issue with the return spring. Hopefully will have a new one shortly and can finally get some dyno numbers to post.
