ECM question

[Mikes07]

i recently picked up a 2001 Silverado HD with the 6.0. Long story short is my buddy who owned the truck before me had an injector problem, replaced with rebuilt ones from rock auto and one stuck open and hydro locked cylinder 5 and broke rod. He picked up another 6.0 out of an 02. Then he lost interest and bought another truck. So I bought his 01 with the 02 motor waiting to be installed. I have it in and have been driving it for a month or so and it doesn't seem to right yet. It runs great, no code, but seems sluggish and unresponsive at times. It also turns over a lot in the morning after sitting. Car starter cycles three times before it actually stays running, once warm it's fine. I've done new sending unit, fuel pressure regulator, coolant temp sensor, fuel filter, airmass sensor, plugs, wires. I'm wondering if it's because it's not the ecm for that motor?

 

[ccapehartusarmyINF.(ret)]

has the fuel pump ever been replaced my tahoe had similar symptoms when the fuel pump was going out
some times in try to start it and itd just crank id have to turn the key all the way off then on the 2nd or 3rd time itd start up

 

[Mikes07]

I've hanged the whole sending unit and filter, sometimes it starts first crank sometimes it just turns over. I ran live data and it does show a potential lean code on front 02 sensors but I have no ses lights.

 

[ccapehartusarmyINF.(ret)]

do you have an aftermarket intake on it?

 

[ezdaar]

swap fuel pump and get it tuned.

Check it very carefully for any vacuum leaks

 

[southboundchicken]

Im thinking a possible bad fuel pump try another one

 

[Mikes07]

It had a spectra cold air intake on it when I bought it.

I have sprayed it down with carb and choke cleaner to check for vacuum leaks and it was fine.

 

[Mikes07]

Just replaced the complete sending unit last week, one I took out was maybe a year old but I figured the check valve was bad in old one and that's why I was getting hard cold starts.

 

[ccapehartusarmyINF.(ret)]

I've hanged the whole sending unit and filter, sometimes it starts first crank sometimes it just turns over. I ran live data and it does show a potential lean code on front 02 sensors but I have no ses lights.

just for kicks id put the stock intake back on see what happens aftermarket intakes on occasion cuase lean mix

 

[Mikes07]

If I had I would def try it. I still think my issue is the ecm.

 

[01ssreda4]

So that I understand your post correctly, the 01 model truck was swapped with an 02 engine? Do you know (just curious) if he swapped the longblock or the complete drop in engine, sensors, TB and all from the new truck? But let me make one thing clear, nothing significant changed between those two years, and every single motor part should be interchangeable.