Kidd7
Well-Known Member
- Joined
- January 13, 2014
- Messages
- 307
- Reaction score
- 116
- City, State
- RTP, NC
- Year, Model & Trim Level
- 2000 X AWD EB 5L
Putting the out there as information and open to any input / comments.
This is on a 2000 Ex 4.0 pushrod 4x4 w/ 254k. Some time ago I rebuilt / replaced the fuel injectors in all my cars. All are 16# injectors; 2 vehicles orange, this one white. At that time I installed orange injectors on the X; Of course I got trouble codes, but she ran fine, fuels trims were near max low.
I have since learned that injector flow rate is at PSI; even though orange and white are 16# injectors they operate at different pressure, hence the issues above.
I rebuilt the white injectors, bought some new gaskets and finally got around to swapping back in the white ones. The install went very smoothly, but I ended up rushing some at the end to finish up instead of just finishing the next day. I forgot a vac line so she wouldn’t stay running. I had cleared the check engine codes, but did not reset the ECU. The 10amp PCM fuse #6 under the hood does not remove power from the ECU; the truck actually started with that fuse removed. Bank 2 fuel trims were near 0; bank 1 long term was way low and short term was kind of all over.
Ultimately, I got all the vac lines attached and she still didn’t idle well. I ended pulling the ECU relay fuse and cranking the engine, that did clear the ECU. I reinstalled that fuse and started her up, went for a short test drive and all fuel trims are near 0; she ran and idled well.
My theory is that since I didn’t reset the ECU the low fuel trims because of orange injectors were still in the memory after I installed the white injectors. The truck was running lean at that point and it would take the ECU a long time to correct, need to be in closed loop. That in addition to a vac leak really screwed up the data and cause the engine to run rough even after things were corrected.
Clearing the ECU brought things back to a baseline.
This is on a 2000 Ex 4.0 pushrod 4x4 w/ 254k. Some time ago I rebuilt / replaced the fuel injectors in all my cars. All are 16# injectors; 2 vehicles orange, this one white. At that time I installed orange injectors on the X; Of course I got trouble codes, but she ran fine, fuels trims were near max low.
I have since learned that injector flow rate is at PSI; even though orange and white are 16# injectors they operate at different pressure, hence the issues above.
I rebuilt the white injectors, bought some new gaskets and finally got around to swapping back in the white ones. The install went very smoothly, but I ended up rushing some at the end to finish up instead of just finishing the next day. I forgot a vac line so she wouldn’t stay running. I had cleared the check engine codes, but did not reset the ECU. The 10amp PCM fuse #6 under the hood does not remove power from the ECU; the truck actually started with that fuse removed. Bank 2 fuel trims were near 0; bank 1 long term was way low and short term was kind of all over.
Ultimately, I got all the vac lines attached and she still didn’t idle well. I ended pulling the ECU relay fuse and cranking the engine, that did clear the ECU. I reinstalled that fuse and started her up, went for a short test drive and all fuel trims are near 0; she ran and idled well.
My theory is that since I didn’t reset the ECU the low fuel trims because of orange injectors were still in the memory after I installed the white injectors. The truck was running lean at that point and it would take the ECU a long time to correct, need to be in closed loop. That in addition to a vac leak really screwed up the data and cause the engine to run rough even after things were corrected.
Clearing the ECU brought things back to a baseline.
