i did a vortec head swap on my 89 chevy truck i have done everything everyone else is doing and and it has no more power then it did before and it runs awful. when its cold it runs ok about like a stock tbi 350 that runs real rich. when it warms up it bogs real bad and seems to be less power then a tbi 350

details about the motor

bigblock TB with afpr
80 lb injectors
vortec heads
custom burnt chip

everything else is pretty much stock

what do you guys think could be the problem?

 

i know a coolant temp sensor problem can cause a rich condition on TBIs. i would double check all the basics and codes. then look into the chip being the problem.

 

thanks i will check that out. thanks for the reply

 

Yeah, it really sounds like the tuning/chip - the new heads are not what is controlling how much gas yer getting. Are your injectors too big?

 

im not real sure about the injectors. the guy who did the chip may be able to fix things up for me but i cant contact him until monday

 

What size are/were the stock injectors? Could you put them back in and see if it runs better or has a better air/fuel ratio?

 

bigblock TB with afpr [/QUOTE]

80 lbs inj with 13 lbs FP should be OK. adding a VAFPR would be a good idea.

You need to datalog and send to burner before you have chip reburned. Unless the burner just errored this is the way to go. Tune is probably the issue.

Ideally you would do burns yourself.

 

Probably a tune issue, however you probably do not need the 80lb injectors and they will make it more difficult to get the tune correct. I would probably go to 61 or 68lb injectors and have the tune redone for them.