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6.0 swap exhaust questions.

Clay_Lucas

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Chris Senior Enthusiast

Chris

Posted
Posted

Tuner should have done the relearn then

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Podor Enthusiast

Podor

Posted
Posted

If it is a Gen 4 (cam sensor on the front cover), you have to deal with the difference between a 58x reluctor and the original 24x reluctor. The cam reluctor is different also. Lengenfelter has a conversion module that is designed to convert the signal so the older PCM can handle it, even with the tune.

Clay_Lucas Enthusiast

Clay_Lucas

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If it is a Gen 4 (cam sensor on the front cover), you have to deal with the difference between a 58x reluctor and the original 24x reluctor. The cam reluctor is different also. Lengenfelter has a conversion module that is designed to convert the signal so the older PCM can handle it, even with the tune.

The engine was out of a 04-05.

 

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Podor Enthusiast

Podor

Posted
Posted

It's highly unlikely the lack of charging is causing the misfire. My '05 regulates the charging system to maximize fuel economy. I'm not sure if that's the same for the older ones. Does the light come on? Also, check to make sure all your grounds are back on and tight.

 

If you have access to a scanner with OE live data, you can see misfire history that can help you narrow down the problem. Launch makes an awesome little scanner for about $325, the CRP123P. It has OE level data on engine, transmission, Abs and airbag for all makes and models and free updates for life.

Clay_Lucas Enthusiast

Clay_Lucas

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It's highly unlikely the lack of charging is causing the misfire. My '05 regulates the charging system to maximize fuel economy. I'm not sure if that's the same for the older ones. Does the light come on? Also, check to make sure all your grounds are back on and tight.

 

If you have access to a scanner with OE live data, you can see misfire history that can help you narrow down the problem. Launch makes an awesome little scanner for about $325, the CRP123P. It has OE level data on engine, transmission, Abs and airbag for all makes and models and free updates for life.

All I have is my Bluetooth scanner. The alternator was definitely bad. Didn't fix the misfire, but now the check engine light doesn't come on as fast or as frequently as it did with the bad alternator.

 

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Podor Enthusiast

Podor

Posted
Posted

OK, there is significant history on 1,8,6 and some on 5. They aren't dedicated to one bank or the other. It's good to start with the basics. When it cranks, the starter pulses should be nice and even. That's a good indication of good compression. Pull the plugs and make sure there isn't something obvious, like a closed or excessive gap, or a broken ceramic or carbon tracking. You can also see if they are wet with fuel or if there are any deposites.

 

The thing that is odd is 1-8 and 6-5 are companion cylinders in the firing order. It is possible that there is a crank relearn needed. If the PCM doesn't know where the crank is in it's rotation, it will think there is a misfire condition. It won't really know exactly when and how to fire the cylinder either. It may be a good idea to do a relearn. You don't have to go to a dealer if you don't have the ability. Most high end scan tools can do it. If there is a good shop you trust that has a fairly up to date scanner, they can do it for much less.

Clay_Lucas Enthusiast

Clay_Lucas

Posted
  • Author
Posted

OK, there is significant history on 1,8,6 and some on 5. They aren't dedicated to one bank or the other. It's good to start with the basics. When it cranks, the starter pulses should be nice and even. That's a good indication of good compression. Pull the plugs and make sure there isn't something obvious, like a closed or excessive gap, or a broken ceramic or carbon tracking. You can also see if they are wet with fuel or if there are any deposites.

 

The thing that is odd is 1-8 and 6-5 are companion cylinders in the firing order. It is possible that there is a crank relearn needed. If the PCM doesn't know where the crank is in it's rotation, it will think there is a misfire condition. It won't really know exactly when and how to fire the cylinder either. It may be a good idea to do a relearn. You don't have to go to a dealer if you don't have the ability. Most high end scan tools can do it. If there is a good shop you trust that has a fairly up to date scanner, they can do it for much less.

Is it very harmful to run the engine befor getting this fixed? I won't ha e much spare time for a few days.

 

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Podor Enthusiast

Podor

Posted
Posted

Good question. I don't think it will do any major damage, but I don't want to say for sure.

  • 2 weeks later...
Clay_Lucas Enthusiast

Clay_Lucas

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Crank relearn seemed to fix it for the most part. I still get the code but it only comes up as a pending falt. I did turn the light on once but hasn't come back (as a current fault) sense.

 

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Podor Enthusiast

Podor

Posted
Posted

Crank relearn seemed to fix it for the most part. I still get the code but it only comes up as a pending falt. I did turn the light on once but hasn't come back (as a current fault) sense.

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Glad it's doing better. Drive it for a week or so and see how it does. It may have been trying to compensate for so long it has to re-learn what is normal. If it doesn't get better after a week or maybe 200 miles or so, go back to the basics; spark, fuel, compression. I really think you have it nailed, I wouldn't stress about it.

mjoekingz28 Enthusiast

mjoekingz28

Posted
Posted

Looks like no one is really sure how back pressure effects engine performance.

I'm mainly worried about losing low end hp/tq. Does the lower compression on the lq4 make any difference?

Is a header wrap worth the money or should I just leave the SS bare, with no coating?

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I dont know about back pressure, but the 'speed' (or velocity) at which you move the exhaust out the back increases torque. The amount(or flow/volume) you get rid of increases horsepower. This, I HEARD!

  • 2 weeks later...
Clay_Lucas Enthusiast

Clay_Lucas

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  • Author
Posted

Misfire codes haven't come back yet.

 

I am having a issue with the new transmission. It has a 2000rpm stall. If I get close to 2k rpm it shudders pretty bad. If I drop down a gear or bring the rpm up it goes away and feels/shifts fine.

 

Is this normal? Hopefully I won't have to replace it. I don't think the tunner did anything for the transmission computer.

 

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