Hey everyone, I am new to this forum. I need a little advice here. I recently had to do a cam gear install and had the timing cover removed. I didn't have the timing jump or anything. I had a scissor gear fail and caused some teeth damage to the spring gear on the cam. Anyways, I replaced the injection pump, oil pump, crankshaft gear and timing gear. I also replaced injector number 7 due to me thinking it was the source of the knock. Now that I have it finished, I have injector advanced codes for 2,5,6, and 7 injectors. I also have a dead miss at idle that goes away with a little throttle. I also have injector knock at low rpm. Do you think I maybe got a bad injector? I have triple checked the timing marks and they are spot on. Does a new cp4 pump need any programming? Also, the number 7 injector was a duralast reman. I haven't got it coded yet, but I don't see that causing a dead miss at idle, but maybe it would. I don't have a bidirectional scanner to narrow it down. I just have a cheap scanner. Would a single faulty injector cause 3 more to advance beyond limit?
2016 LML. Maybe a bad injector?
- Thread starter flyinwrenches
- Start date
Here are the codes p02cf, p02d9, p02d5, p02d7. There was 7 codes at the time I scanned it, but the other 3 were because I had a couple of connectors unhooked. It was a MAF, boost code, and a coolant temp code. I plugged in the connectors and they went away. The 4 injector codes have stayed however.
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Check the harness for chafes, breaks or bad connections. Might need to load test it. Also, compression test
If all checks good you might need injectors
If all checks good you might need injectors
Ok, I might have to take it somewhere for further test. I don't have a picoscope or a bidirectional scan tool. What's weird is that I didn't have any codes or run issues before the ip and injector change. I only changed the pump because I was already tore into it and figured I might as well. I pulled the regulator on the old pump and it was clean as a whistle. No metal or anything. It has to be something I did, but I just don't know what. Like I said, I double checked the timing marks and everything was lined up perfectly. That leads me back to the pump and injector change. I have checked wiring and don't see anything messed up. I thought I was doing right by changing new parts, but I reckon I should have left the fuel system alone.
I know the injector timing is set by the crank and cam sensor readings. I suspected a misaligned reluctor or tone wheel, but everything seems to be lined up pretty good. And I reckon if it was something that I reassembled incorrectly on the front gear drive, then all 8 would be advanced wouldn't they? Also, I think the LMLs injectors are controlled in 4 group sets right. So, if injector 7 had an open circuit or something, then only 2 injectors would go down right? And since the fuel trim on 7 is off, then I suppose the ecm balance rates would be off, but would it cause a dead hole?
Edit- when I say "dead hole", I have not confirmed it is dead, but the whole engine shakes at idle and smooths out at higher rpms. When it shifts to overdrive, it also shakes the truck like a misfire or no combustion causing an imbalance. If you just floor it, then all 8 cylinders hit and it will pin you back to the seat.
Edit- when I say "dead hole", I have not confirmed it is dead, but the whole engine shakes at idle and smooths out at higher rpms. When it shifts to overdrive, it also shakes the truck like a misfire or no combustion causing an imbalance. If you just floor it, then all 8 cylinders hit and it will pin you back to the seat.
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You have timing off or an imbalance in the engine. Those codes are set when the computer cannot see an advance or retard from increasing or decreasing timing for the main firing event.
I would verify you don’t have a broke engine crank, no sheared pins in the crank or cam shaft, converter has not drained fluid back to the point it needs to fill back up (put it in gear and see if it moves) or something else along those lines.
I doubt it’s electrical if that’s all the codes you got
I would verify you don’t have a broke engine crank, no sheared pins in the crank or cam shaft, converter has not drained fluid back to the point it needs to fill back up (put it in gear and see if it moves) or something else along those lines.
I doubt it’s electrical if that’s all the codes you got
Ok, well I did replace the reluctor wheel with a used one from ebay and a new cam gear from rockauto. I had a scissor gear fail. There was no broken pins or problems like that. The crank was not broke. I had the trans dropped and removed the upper and lower oil pan. I just don't know what I could have out of time. I even took the cover back off and didn't see anything out of place. All the timing dots were lined up where they should be and the crank reluctor and cam tone plate were lined up where they should be. Wouldn't it be all of the injectors and not just 4 of them? Do you think I should buy a new reluctor wheel?
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So you know for sure the crank gear did not spin on the crank? Does the truck move when put in gear?
Yes, it shifts fine and moves fine....I maybe should take it back apart and check the pressed on crank gear, but the oil pump drive gear/crank reluctor gear still has its pin. If the pressed on gear spun, I would probably hear valve contact and bad noises though wouldn't I?
It runs like a scalded ape when you floor it. It only stumbles at low rpms and idle. I am not sure that helps any
The only gear that I didn't check was the injection pump gear. It came pre-installed on the new injection pump. It was a gm genuine pump. Is there any possibility that the injection pump gear could have been installed without a pin? I just though about that
Sorry for all the questions guys. I just stumbled upon this...
System Verification
1-Verify the proper fuel is used. Refer to Fuel System Specifications and Contaminants-in-Fuel Diagnosis.
2-Verify there are no aftermarket performance enhancing devices installed on the vehicle.
3-Perform the Fuel Injector Correction Reset for the appropriate fuel injector. Refer to Fuel Injector Correction Reset.
4-Perform the Crankshaft Position Reluctor Wheel Learn. Refer to Crankshaft Position Reluctor Wheel Learn.
5-Perform the Fuel Injector Timing Learn to verify that the DTC does not reset. Refer to Fuel Injector Timing Learn.
If DTC resets
Refer to Circuit/System Testing.
If DTC does not reset
All OK."
I changed the crank sensor and reluctor wheel and injector. Do I need to perform a relearn procedure?
System Verification
1-Verify the proper fuel is used. Refer to Fuel System Specifications and Contaminants-in-Fuel Diagnosis.
2-Verify there are no aftermarket performance enhancing devices installed on the vehicle.
3-Perform the Fuel Injector Correction Reset for the appropriate fuel injector. Refer to Fuel Injector Correction Reset.
4-Perform the Crankshaft Position Reluctor Wheel Learn. Refer to Crankshaft Position Reluctor Wheel Learn.
5-Perform the Fuel Injector Timing Learn to verify that the DTC does not reset. Refer to Fuel Injector Timing Learn.
If DTC resets
Refer to Circuit/System Testing.
If DTC does not reset
All OK."
I changed the crank sensor and reluctor wheel and injector. Do I need to perform a relearn procedure?
DDiesel on this forum said this...
"Working on a 2016 lml. Truck had a broken crankshaft. Replaced crankshaft. Does crankshaft position need to be relearned? I know it does on some GM vehicles. Truck runs and drives but has p02CD cylinder 1 injector exceeded limits and p02D3 cylinder 4 injector exceeded limits.
His solution....
I read something about driving the truck from 40-65 and repeating it about 30 times to relearn. I tried it. No codes now and truck runs smooth."
Is there any truth to this?
"Working on a 2016 lml. Truck had a broken crankshaft. Replaced crankshaft. Does crankshaft position need to be relearned? I know it does on some GM vehicles. Truck runs and drives but has p02CD cylinder 1 injector exceeded limits and p02D3 cylinder 4 injector exceeded limits.
His solution....
I read something about driving the truck from 40-65 and repeating it about 30 times to relearn. I tried it. No codes now and truck runs smooth."
Is there any truth to this?
The cp4 doesn’t need to be timed. It was timed from factory to help with harmonics but won’t cause your issue. Wouldn’t worry about that.
Yes I would follow that being that everything else is checking out good
Yes I would follow that being that everything else is checking out good
Ok, I will get it to someone to hook it up to their computer. I may go to the dealership since they have tech 2. Thanks so much!
Hey glad to see you over here. Depending on the problem this forum is a better help and as a whole has better and more techi members. As you probably found out you got better help than the other forum. And by the way im not sure a tech 2 will work on your truck. The newer GMs have a newer system that is used.
Depends on the year. Tech2 will work up to 15 in some cases even though it says it only goes to 13. An mdi2 will work on all LML’s and worse case, you use tech2win through the mdi2. All Chevy dealers will have one of those
Hey, I didn't realize there would be someone familiar on here from the other forum. I appreciate all the help you gave me on the other forum. Thanks for informing me about the tech 2.
Nate's Dmax is correct. I know him from another forum and he already knew my truck is a 2016. Sorry I didn't add that in the description. You sure know your stuff though. I sure appreciate you helping me.