rebuilt engine problems

[k_pro1992]

the engine was just rebuilt but its running really rough and has misfires on multiple cylinders and is idling around 400-500 rpms.

any ideas on what could be wrong?

 

[bigwavedave]

Timing

 

[k_pro1992]

thanks do you know what the timing is supposed to be set on for a 350 vortec

 

[bigwavedave]

Nope....But you are having misfires and strange idle. I would start by resetting everything to TDC and make sure you are not 180 out.....

 

[darren250r]

On the vortecs, you aren't adjusting the timing when you turn the distributor. You're adjusting the cam retard. You need a tech II or equivalent scan tool to set the cam retard. You want to set it to 0+/-2 degrees. That will give you a separate code/check engine light though.

Double check and make sure that you don't have the spark plug wires crossed. There are a couple that if switched will still run, but crappy.

Make sure one of the spark plugs didn't get broken when putting them in.

Scan for any stored codes if you haven't already. Any check engine light?

 

[k_pro1992]

one check code for o2 sensors and one for multiple misfires.

 

[DRAGGIN95]

Yeah I'd say double check the firing order.

 

[k_pro1992]

well i checked my firing order and bought new o2 sensors only to figure out my injectors were sticking so ima change those out and see if it fixes my problem. thanks for the help.

 

[emazingli]

Keep on posting on updates of your rebuilt engines k_pro1992. Much appreciated if there are pics of rebuilt transmissions as well.

 

[Tinbender59]

cyl's 5 & 7 will let it still run, but like crap. and you will get the same issues if timing is off to far, been there!! done that!! O2 codes and all. these Vortec's are real finicky animals.