4.3 Vortec...I had a used engine with 150,000 km put into my truck. They had to redo the plug wires and a put a new oil pump on as well. Now the truck stutters and coughs and acts hard to crank-mostly when cold, and she shudders alot, when it does start. Had my uncle, a mechanic look at it and he said timing was off..but these trucks have the computer set the timning I believe...

Can someone help here? going back to the shop that put my used motor in is not an option as they did it cash....

starter is brand new too..

 

The distributor can be adjusted (it's a loose fit into the bore through the lower intake manifold), but it requires a scan tool capable of displaying 'CMP Retard' in order to set it to zero.

If they pulled the distributor, it is possible it isn't even installed correctly. Take a read through the Tech Article (DIY) Index link in my signature below for the EDI Engine Timing thread. Run through it all just to be sure.

 

Thanks for the helpful info. Will let you know how things go....