Ok, so I just "finished" my 6.0 swap, and it does run.

The current setup is an LQ4, with a 216/224 .561/.568 114, and open LTs (trying to get the y-pipe modified later today), TT3000, and an FLT level 5.

If it idles for more than a few seconds, it starts misfiring, and the SES light flashes.

If I start driving before the misfire appears, the light doesn't come on, and it seems to run right for the most part, but as soon as I stop and let it idle, the misfire comes back/SES light flashes. If I start moving again, it misses like crazy.

If I shut the truck off and start it again, and start driving before the misfire(s) appears, the light stays off.

I am about to go out and buy a code reader, so that should provide some more info soon, and yes, the truck is tuned for the modifications (probably not perfectly, but I sent the PCM down to Justin at Black Bear, and he adjusted for everything the best he could without the truck there).

Basically what I'm wondering, is has anyone else had this issue, or can you see anything that stands out in my setup that would cause this?

Thanks a bunch for any help, I need to get this thing running right, I go back to school on Monday.

EDIT: I've also been told that I may need a crank relearn done, but if that were the case, wouldn't the misfire be constant?

 

Bummer Dan...I'm glad you got the engine in, but the misfire part sucks. Is it actually missing or just the flashing light? Maybe a loose connection somewhere?

 

That's what I was gonna say, check the harness for the ignition coils. I had a similar problem after swapping in 6.0, turned out the harness was connected good enough.

 

It's noticeably missing, especially under load.

I sprayed some carb cleaner around the intake manifold, and everywhere else that could cause a leak after the MAF, and no change, so I don't think it's a vacuum leak (just trying to eliminate as much as possible).

Just got back from picking up a code reader, I'll find out exactly what code it's throwing and report back in a few.

 

ya id say before anything go back and check every connector on the motor..i had a loose ground that gave me troubles for a week after i swapped mine

 

Just read the codes, getting P0300 (random/multiple misfire), and P0174 (bank 2 too lean).

The one common cause between those two seems to be a vacuum leak...

 

Just checked all of the connectors and grounds on the motor, and everything is good.

Can anyone verify whether the crank relearn (or CASE relearn) needs to be done or not?

 

could it be the tune since u upgraded motors? and after all u did put a cam in it. so i t should of affected alot on tune

 

isnt getting a misfire code after a cam swap pretty common?

 

I believe it should all be tuned properly (or at least pretty close), Justin reflashed the PCM, according to the specs on everything I'm running.