Hopper
10-31-2019, 04:32 PM
I'm struggling on two items I was hoping you guys could help with.
I swapped in a 92 tbi 454, 4l80e, harness and computer all out of the same rig into my suburban. It was a 91 tbi 350, 4l80e already. I now have no check engine light. My understanding and the way I remember it is that the CEL should light up when the ignition key is turned on and go out once the vehicle start up and runs. Am I wrong? Being an OBD1 rig, I have even tried jumping the ALDL port to get codes and still no light on the dash. After looking at the wiring diagrams, the cluster has a keyed ignition power supply "pink w/black" that heads into one side of the CEL and then heads to the computer via a green w/ white wire if I remembering correctly on the colors. I don't see any other interruptions in the lines and check continuity through the wires. Am I missing something??? Does the computer ground out the light to make it go off or flash codes?
My other item is I must be back feeding my speedo somehow. When the vehicle is started the speedo starts jumping up and down around 20 to 45 mph. I started chasing wires. My understanding of the wiring diagrams and what I chased is the vss off the tail shaft on the transfercase send the signal via 2 wires all the way to the DRAC or the VSSB depending on what you want to call it. Purple w/ white and green w/ black I'm pretty sure for colors. This signal leaves the VSSB and send the signal to the speedo in the cluster. All I can think is I have messed up a wire or signal to the VSSB. Again, any thought would be helpful. i haven't touch any wiring inside the truck. All my wires addressed have been through the engine compartment.
My suburban starts and runs but isn't usable. It's very frustrating. Upon slow to medium throttle is move and drives but if I try to punch/chop the throttle or punch it, it stalls out, chokes, or falls on its face. However you want say it. I'm hopping the CEL will shed some light on what not working correctly. Thank you.
I swapped in a 92 tbi 454, 4l80e, harness and computer all out of the same rig into my suburban. It was a 91 tbi 350, 4l80e already. I now have no check engine light. My understanding and the way I remember it is that the CEL should light up when the ignition key is turned on and go out once the vehicle start up and runs. Am I wrong? Being an OBD1 rig, I have even tried jumping the ALDL port to get codes and still no light on the dash. After looking at the wiring diagrams, the cluster has a keyed ignition power supply "pink w/black" that heads into one side of the CEL and then heads to the computer via a green w/ white wire if I remembering correctly on the colors. I don't see any other interruptions in the lines and check continuity through the wires. Am I missing something??? Does the computer ground out the light to make it go off or flash codes?
My other item is I must be back feeding my speedo somehow. When the vehicle is started the speedo starts jumping up and down around 20 to 45 mph. I started chasing wires. My understanding of the wiring diagrams and what I chased is the vss off the tail shaft on the transfercase send the signal via 2 wires all the way to the DRAC or the VSSB depending on what you want to call it. Purple w/ white and green w/ black I'm pretty sure for colors. This signal leaves the VSSB and send the signal to the speedo in the cluster. All I can think is I have messed up a wire or signal to the VSSB. Again, any thought would be helpful. i haven't touch any wiring inside the truck. All my wires addressed have been through the engine compartment.
My suburban starts and runs but isn't usable. It's very frustrating. Upon slow to medium throttle is move and drives but if I try to punch/chop the throttle or punch it, it stalls out, chokes, or falls on its face. However you want say it. I'm hopping the CEL will shed some light on what not working correctly. Thank you.