Matt Swany

Ok iv just replaced a cracked manifold ansolute pressure sensor. Not it runs but I can't give it any gas or it stumbles and dies... and if I advance timing it sounds really good but dies seconds later. I need help. Oh and I replaced cps.

Matt Swany

.ok I have spent way to much time trying to get this truck running. At the moment it will start and idle fine. When its cold I can rev it with no problem. After a wile it will stumble and pop if gas is given. I can drive it around my driveway but either dosent want to go or goes all out, is having problems under a load. Iv replaced a lot on it and am running out of ideas. Also its a new motor in it a 350 over the orginial 305. Do I have to get the computer flashed? What would that do. Cause it seems like its in fine timing but once it warms up it has major problems, would not haveing the computer flashed cause this. I would greatly appreciate any ideas on where to go from here. It doesn't have the pass lock I believe

2wd-K5

yea, the comp may need to be re-flashed, but first try the throttle body off a 350, they have bigger injectors. this may be the problem you have, when cold, it dumps more fuel in then when warm the fuel suply is cut back

tinbender59

Throttle Body??? what the ???? this is a Vortec, ya know CPFI that means that it has independent injectors, 1 per cylinder. throttle body is only going to improve WOT (wide open throttle) and YES YOU need to reprogram 305 takes 19lbhr injectors, and 350 takes 22lbhr units If you are not going to turn over 6Krpm reprogramming is all you need. The 19lbhr units will do fine with stock 350, up to 6000 rpm. Right now you are way to lean and risk burning up valves, quit driving it until you get reprogrammed!!!!!

tinbender59

Ok after rereading your thread, it is most likely the injectors, or rather (CID - Injector - ECM program combo) is incompatible, get the ECM reprogrammed

2wd-K5

whoops my bad, forgot the year, too many of these type of articles for me lol

tinbender59

I understand Been there done that