Stumped
Junior Member
Hello all, I’m new here and am helping my neighbor with his truck. It has me baffled. Only shows “rich bank one” DTC code. Cold the truck starts right up then dies. Then second crank I have to hold the gas down for it to fire. It searches for idle between 200 to 800 rpm’s a few times then dies. I can keep it running steady at 1,800 rpms but as I let up it searches for idle and dies. Truck will rev to 5k no problem. So that rules out the catalytic converter being clogged. The previous owner replaced the coil packs and wires. Scanner numbers and what I have done are the following:
Scanner-
1) O2 sensors are pegged rich at .92-.98
2)short and long term fuel trims at (-30) showing computer is trying to pull fuel out.
3)injector pulse width at idle is 9-10 plus while it is only 1.4 at 1,800 rpm’s. I believe it should only be 2.5-3.5 at idle and increase as you accelerate. So this seems backwards and potentially the culprit. But having changed the map sensor made no difference.
Work done-
1) Installed correct plugs. Previous owner had wrong plugs.
2)Installed new valve cover gaskets and checked for broken springs
3) compression test. all cylinders within 10-12 lbs, 168-180.
4) had fuel injectors cleaned. All spraying equal
5) had red lightning bolt light on, so replaced throttle body. Light gone.
6)ruled out evap valve. Is clean and working.
7)replaced map sensor with no change to symptoms
I am completely out of ideas. And need help. Thank you all in advance.
Scanner-
1) O2 sensors are pegged rich at .92-.98
2)short and long term fuel trims at (-30) showing computer is trying to pull fuel out.
3)injector pulse width at idle is 9-10 plus while it is only 1.4 at 1,800 rpm’s. I believe it should only be 2.5-3.5 at idle and increase as you accelerate. So this seems backwards and potentially the culprit. But having changed the map sensor made no difference.
Work done-
1) Installed correct plugs. Previous owner had wrong plugs.
2)Installed new valve cover gaskets and checked for broken springs
3) compression test. all cylinders within 10-12 lbs, 168-180.
4) had fuel injectors cleaned. All spraying equal
5) had red lightning bolt light on, so replaced throttle body. Light gone.
6)ruled out evap valve. Is clean and working.
7)replaced map sensor with no change to symptoms
I am completely out of ideas. And need help. Thank you all in advance.
