Alright long winded post.
Have a 2003 lb7 I did a set of injectors in came in needing a set (knocking on 4 and 7). Replaced the set with s&s injectors. I fired truck ran good pulled it out told customer it was ready. Customer shows up we fire it up sounds off and has a noticeable miss.
Number 3 has a +15 rate. So pull it back then it changes to number 2 at +15. This continues to bounce around. I swap my ficm from my personal truck fires up sounds great think I have it fixed. Get a replacement ficm in it fire it up runs fine after test drive rail pressure starts surging
kicks regulator performance code repalce fpr rails happy but now I have random cylinders dropping again. Swap my ficm in same story. So I ohm wiring from all injectors to the ficm all are fine. Ohm to ecm for command wires all check out.
Start the truck and park it outside for a couple days to get other things done.
Now the truck won't even fire builds 23k rail pressure and won't even fire any injectors. Swapped a good ecm in. No change.
I have looked everywhere for what I should see for voltage at the injector plug and I'm getting 14 volts key on and while cranking.
I have verified voltage to every point prior and to the ficm. The grounds from the ficm to the block are good and test fine.
I added another ground to the truck just for kicks to know I had a good ground from the engine to cab and battery.
I have lost my mind trying to figure this out. I have replaced and or swapped everything. It has zero codes between both ecms. Never once has had code for ficm, misfire or voltage performance of any kind this entire time.
Anyone got any ideas before I burn and turn it into insurance
Have a 2003 lb7 I did a set of injectors in came in needing a set (knocking on 4 and 7). Replaced the set with s&s injectors. I fired truck ran good pulled it out told customer it was ready. Customer shows up we fire it up sounds off and has a noticeable miss.
Number 3 has a +15 rate. So pull it back then it changes to number 2 at +15. This continues to bounce around. I swap my ficm from my personal truck fires up sounds great think I have it fixed. Get a replacement ficm in it fire it up runs fine after test drive rail pressure starts surging
kicks regulator performance code repalce fpr rails happy but now I have random cylinders dropping again. Swap my ficm in same story. So I ohm wiring from all injectors to the ficm all are fine. Ohm to ecm for command wires all check out. Start the truck and park it outside for a couple days to get other things done.
Now the truck won't even fire builds 23k rail pressure and won't even fire any injectors. Swapped a good ecm in. No change.
I have looked everywhere for what I should see for voltage at the injector plug and I'm getting 14 volts key on and while cranking.
I have verified voltage to every point prior and to the ficm. The grounds from the ficm to the block are good and test fine.
I added another ground to the truck just for kicks to know I had a good ground from the engine to cab and battery.
I have lost my mind trying to figure this out. I have replaced and or swapped everything. It has zero codes between both ecms. Never once has had code for ficm, misfire or voltage performance of any kind this entire time.
Anyone got any ideas before I burn and turn it into insurance
