Ok, my friend just bought a early 99 F250 PSD with 180,000mi. When we went to look at it the motor was skipping pretty good but wasnt making any noise or smoking. After it ran for like a hour it kinda smoothed out but was still a dead miss when you hit the gas. I suspected bad injector(s). Ive never done a injector on a 7.3 but I own one myself so it was time to learn. So we bought it (cheap). I scanned it on a OTC Genisis scanner that Ive used before to buzz test a 7.3. When I scanned it I just got a few Exhaust back pressure codes and a low turbo boost code. So I cleaned out the tube to the EBP sensor and swapped the sensor with a known good one. Now on to the buzz test....... All 8 buzzed then in the test the 1st buzz was almost non existant and the next 7 sounded normal. So I was guessing Cyl #1 was our culprit injector. Also when I did a cylinder contribution/balance test cyl #1 AND 4 failed the test?
So today we robbed a injector out of another totalled 7.3 that we have that still runs perfect. We replaced in the new truck and after a while the idle skip cleaned up for the most part but when the throttle is applied you still feel it missing a cylinder. So my question is do you think its just another bad injector or mabey a bad IDM or a valve cover harness? We wiggled and unplugged the VC harness and nothing changed. I know some of these trucks had issues with loose plughs on the harness.......and on the new truck there is a white zip tie on the connector clip on the inside of the VC. Is that stock or was it a fix?
Anyone that has experience in this please help me out