I got a 03 and I just had the motor rebuilt and put F1 injectors in it. Anyway, When I start it up after sitting and having time to cool down, it runs like crap until it gets warm then it runs perfect. It idles really rough and spits and sputters. Its really slugish til it warms up. After its warm it runs great until it gets cold again. I did notice couple puffs of blueish smoke out of the exhaust. I also noticed it takes a little longer cranking over til it fires up. Any ideas or anybody had this problem?

 

How cold is it outside when this happens?

 

Prob between 30-50 F. It has been a very warm winter here so far. It never did this before the rebuild. I did have it bored 20 over. Dont know if that will matter much.

 

Check batteries for low voltage, load test them.

 

Don't mean to alarm you, but blue smoke, slow to start (diesels are compression fired) and sputtering....

Sounds like poor compression. You went .20 over, did you put the oversized rings in? Maybe the rings just need to seat. Have you pulled hard with it yet?

 

Havent pulled anything. I put prob bout 8k miles on it since rebuild.

 

Hook that truck up to a 4-8K loaded trailer and run it for a few thousand miles to seat the rings. I have never understood why so few are willing do what rights and work a new/rebuilt diesel engine to seat the rings during its first 5,000 miles.