jmcgyver29er
+1y
Thanks guys, I think I'll get it figured out eventually.
As far as the blue wire in the video and the dwell meter hook up. The blue wire is my patch wire inserted into the white diagnostic plug, hooked up to the positive on the dwell meter and the negitive is hooked to the ground(-)on the battery.
I don't get any dwell reading from the green plug. Only a voltage reading on the multimeter. I think there is a way to check the fuel mixture @ idle from the green plug by reading the output volts or ohms or something. Further investigation is required to adjust the idle fuel mixture that way. But that's not my problem right now.
I found the connector on the temp sensor bottom of the rad to be corroded and not hooked up. So that was probably part of the problem for the ECM and running in limp mode (rich). I reconnected it.
So I put a back probe wire in to the connector of the O2 sensor so I could get some readings off that to see if I was still getting the rich condition at high RPM. The O2 sensor is brand new. The default voltage from the O2 sensor is supposed to be 4.5 volts with a max output of 1.01 volts. If the output is close to 1.01 then the O2 sensor is reading a rich condition, closer to zero a lean condition. So I adjusted the idle mixture screw on the carb @ idle to give a reading fluctuating above and below 4.5 volts @ idle.
When I rev the engine the O2 sensor peaks up close to 1.01v. Then while still at high rpm, when I ground the diagnostic plug, to check the Air/ fuel solenoid. The O2 sensor voltage drops down to a lean condition, like close to .01v.
That tells me the Air/ fuel mixture solenoid is good, it's just not getting the signal from the ECM to kick in when the engine revs.
Now I just discovered that when I disconnect the vacuum sensor hose and plug the hose, then rev the engine, the O2 sensor voltage goes high then it starts to give a leaner reading and fluctuates up and down from .01-.09 And the dwell meter reading goes from close to Zero like in the video I made, up to a higher level. Which corresponds with a OEM carb trouble shooting guide found on the web, about checking the DWELL.
So maybe I have found the problem. Faulty vacuum sensor. One of the causes of a low dwell reading from the diagnostic plug according to the OEM carb trouble shooting guide found on the web.
Anyone know how to test the Vacuum Sensor? ie back probing with a multimeter.