Slight popping out my exhaust

DieselP

DieselP

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Jun 2, 2013
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My truck currently pops just a little around 2500 to 3000rpm at full throttle only.
Not sure what this could be or is?? The injectors are brand new, new fass, only thing still factory is the cp3. Could this be the tuning?
 
Were the injectors recal'd to the ECM? 6.7 injectors when replaced have to be recal'd by using the 5 or 6 digit number on the injector corresponding to what cylinder it's in.
 
MAXTORQ said:
Were the injectors recal'd to the ECM? 6.7 injectors when replaced have to be recal'd by using the 5 or 6 digit number on the injector corresponding to what cylinder it's in.
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I'm not exactly sure what you mean, but the injectors are the stock ones that came out, just sent them to exergy for nozzles and testing.
 
Ok so did the injectors all go back in the same cylinder they came out of?
 
MAXTORQ said:
Ok so did the injectors all go back in the same cylinder they came out of?
Click to expand...

To be honest I don't know I was out of town working and had a shop do it, but if they weren't that can cause this?? And if so can I pull them and is there a way to tell where they need to go??
 
Yes it can. The ECM will have CAL numbers that are published on the injector. These numbers must be written down prior to install. Once installed the tech will have to get his high dollar scanner out and program each injector to the cylinder it came out of. This is ofcourse that he injectors where not numbered on removal and then stuck back into any cylinder after the injectors were freshened up.

Now if the tech understands this and he got all the injectors back in the same cylinders that they came out of the next thing I would look at is valve lash on the exhaust rockers. Being that they are removed during the removal and install process.

This whole thing is called Cylinder Balance.
 
MAXTORQ said:
Yes it can. The ECM will have CAL numbers that are published on the injector. These numbers must be written down prior to install. Once installed the tech will have to get his high dollar scanner out and program each injector to the cylinder it came out of. This is ofcourse that he injectors where not numbered on removal and then stuck back into any cylinder after the injectors were freshened up.

Now if the tech understands this and he got all the injectors back in the same cylinders that they came out of the next thing I would look at is valve lash on the exhaust rockers. Being that they are removed during the removal and install process.

This whole thing is called Cylinder Balance.
Click to expand...

Thank very much, I will look into this! And if I was to drive the truck for a week or so before I did this would it cause issues?
 
Interesting didn't know that 6.7's were sensitive to what injector came out of which hole.

My simple mind says they are new and balanced so it shouldn't matter unless the ECM remembers how the old injectors were balanced in which case couldn't a guy just load a new tune?

If lash was off that much seems like it could be heard at idle.

I'd run a lower hp tune almost sounds like to much duration and not enough cp3.
 
estrada5.9 said:
Interesting didn't know that 6.7's were sensitive to what injector came out of which hole.

My simple mind says they are new and balanced so it shouldn't matter unless the ECM remembers how the old injectors were balanced in which case couldn't a guy just load a new tune?

If lash was off that much seems like it could be heard at idle.

I'd run a lower hp tune almost sounds like to much duration and not enough cp3.
Click to expand...

Yes the ECM remembers the original cylinder balance even if the original injectors were pulled out and not numbers the ECM get confused. Only way to fix the problem is pull the injectors record the numbers on the body of injectors and reinstall. Then input the numbers into the cylinder balance test. The scanner will then recall the ECM. ECM will now start a balance test with the tech enabling the test through the scanner. Test takes about 5 min with the engine at idle.
 
estrada5.9 said:
Interesting didn't know that 6.7's were sensitive to what injector came out of which hole.

My simple mind says they are new and balanced so it shouldn't matter unless the ECM remembers how the old injectors were balanced in which case couldn't a guy just load a new tune?

If lash was off that much seems like it could be heard at idle.

I'd run a lower hp tune almost sounds like to much duration and not enough cp3.
Click to expand...

I have it on the smallest tune I have which is a towing tune with stock duration, the race tune is the same tune with more duration which I haven't ran it the truck hauls ass without it.
 
MAXTORQ said:
Yes the ECM remembers the original cylinder balance even if the original injectors were pulled out and not numbers the ECM get confused. Only way to fix the problem is pull the injectors record the numbers on the body of injectors and reinstall. Then input the numbers into the cylinder balance test. The scanner will then recall the ECM. ECM will now start a balance test with the tech enabling the test through the scanner. Test takes about 5 min with the engine at idle.
Click to expand...

I will look into this Monday and see if they put the injectors in the same hole!! Didn't know this was so important I'm new to the cr, more of a ppumped 24 guy haha
 
Well if they give you a dull look of a trapped animal you will have your answer.
 
Ok guys was messing around this morning and I reved the truck up in park the slight miss/pop happens around 3k then too, and get a little rougher the higher the rpm goes. Also if you just slightly tap the throttle is revs a little rough at low rpm as well. if you mash the pedal its smooth until 3K???
 
Your Sig says EFI tuning. Did you get new tunes written for the bigger injectors?

FWIW, the trim code on the injector isn't the code that the ecm needs, it has to be converted to hex format. The process that MAXTORQ was talking about I've never done before. I know for a fact that you can just change them all to the same code and have no I'll affects. IIRC EFI live has access to that.
 
The tunes were written knowing what injectors and everything I had put on. I had smarty and added the injectors, turbo, fass, and with that I changed to Efi by Ryan
 
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