Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
2006 2500hd lq4 gas, gets random misfires on all cylinders, no check engine light. Has all new injectors, coils, plugs, wires. Grounds cleaned, maf sensor cleaned, vac hoses checked, new knock sensors. Suspected crank sensor issues. No access to a scope
Do you have access to Scan Data? What do your Fuel Trims look like?
"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer." I have learned more by being wrong, than I have by being right.
Yes long term was at 9 bank 2 and 6 bank 1, thought everything was pointing towards dirty injectors, replaced them and now fuel trims are about 2 long term both banks. Forgot to mention intake gasket is also new, replaced a year ago. Misfire is mostly at idle randomly on all cylinders. Thanks for the reply
Fuel pressure is at 60 psi, and is only about 3 months old, Delphi unit. I also done my best at a back pressure test suspected a clogged cat on bank 2 which made some noise at times in the past, reading was between 0 and 1 but needle was erratic
Well the 9185 won't do mode 6 so you won't be able to get misfire data from the computer with what you have. How do you know it's on all cylinders if there is no codes for misfires. Could it be on 2? I would start with a load balance test to see if you can isolate which one(s) are the culprit.
Have been swamped with work lately appreciate response will try and check stft and Ltft at 2500 today. Again misfire data is coming from torque pro app, all cylinders not constant just random at idle. Thanks for all the help
Ok it's only 12 degrees here today, at idle stft1 is -1.3, stft2 is -0.8, ltft1 8.6, ltft2 7.8. At 2500 rpm I have stft1 -3.6, stft2 -2.3, ltft1 9.4, ltft2 8.3
