[RFI] RFI From 2003 Toyota Tacoma

[john heinrich]

I have a 2003 Toyota Tacoma SR 5 Extra Cab truck with a 2.4 ltr 4 cyl. I have an Icom 706MK2G in the truck and the antenna is a tarheel 100 mounted on the driverside rear in a fold over hitch mount. The Antenna  mount attaches to the rear of the frame rail. I have a ground strap going to the antenna. I have tied all the body panels together. I am getting static on 20 and 17 meters when the engine is running.( I think it is presant on all the bands bellow 20 meters as well, but due to the level of static usually presant on these bands I am not possitive) 15, 12 and 10 meters are not effectedThe signal strength is s5 to s7 and does not change when the engine rpm is increased with the gas pedal. When the Idle speed is kicked up via the engine control computer there is a slight change in the static. I have a good ground on the radio. The interferance stops when I disconnect the coax from the antenna. I have tried tracing the source of the interferance using an RFI sniffer and I h
 ave
 found several different locations, and I think the source location is the engine control computer. I am now trying to find a way to trace the exact wire or wires  broadcasting the interferance. I am also not sure how to eliminate the problem once I locate the source wires.
 
 I was able to stop the interferance once when I tried grounding the airflow sencing module. The Check engine light also came on due to the ground. I believe this temporarily shut off the computer. I turned off the engine and waited a few minutes after ungrounding the sensor and then started the engine again. the check engine light was now off and the interferance was back.
 
Any suggestions would be greatly appreciated. 
 
 
John ND6H