RegisterSearchFAQMemberlistUsergroupsLog in
Reply to topic Page 1 of 1
7.4 Vortec Sporatic trimmers
Author Message
Reply with quote
Post 7.4 Vortec Sporatic trimmers 
I have 97 dually 454 vortec that i just had rebuilt. now that its back in and running, it has trimmers, like it has a dirty injector maybe? but its not consistent, and it only spits and sputters when its under load or acceleration. if i downshift and run it up to about 3k or more it sounds clean, but as soon as i give it more gas, it sputters. i ran a tank of 93 through it with two bottles of lucas. no change. does that sound like an injector problem? if so, how would i troubleshoot? FYI its not throwing any codes to my knowledge. no CE light. for those two sroke guys out there, it feels like it needs cleaned out and i just cant get it to blow through.

View user's profile Send private message
Reply with quote
Post  
I once had a VERY similar issue with my bored out 454/460 after coming back from the machine shop.
I think they put the crank position sensor in the acid bath with the other parts. I replaced the crank position sensor and all went well..... if not that.....
For diagnostic purposes I would replace your distributor cap. Those are known to send the spark to incorrect cylinders. It's a cheap and easy elimination. Then check your air filter, fuel filter(replace) check fuel pressure under load.
Those injectors are complete shit anyway. I upgraded my stock injectors to modified LS1 injectors and changed the flow rate in the ecm and the motor ran a whole lot smoother(granted there was nothing wrong technically with the stock setup, just was upgrading to a more efficient injector) there are stock replacement 19# injectors on eBay (but better spray pattern design than stock)
Good luck

View user's profile Send private message
Reply with quote
Post  
stroker97k1500 wrote:
I once had a VERY similar issue with my bored out 454/460 after coming back from the machine shop.
I think they put the crank position sensor in the acid bath with the other parts. I replaced the crank position sensor and all went well..... if not that.....
For diagnostic purposes I would replace your distributor cap. Those are known to send the spark to incorrect cylinders. It's a cheap and easy elimination. Then check your air filter, fuel filter(replace) check fuel pressure under load.
Those injectors are complete shit anyway. I upgraded my stock injectors to modified LS1 injectors and changed the flow rate in the ecm and the motor ran a whole lot smoother(granted there was nothing wrong technically with the stock setup, just was upgrading to a more efficient injector) there are stock replacement 19# injectors on eBay (but better spray pattern design than stock)
Good luck


Thanks, that's good info, I'll look into the crank position sensor. That's one of the few electrical parts i didn't replace in the reassembly. unfortunately, the entire distributor is new (from Auto zone) along with plugs, wires, knock sensors, EGR etc.. I did just buy a fuel filter but haven't had a spare second to change it. What injectors did you upgrade to? I've been thinking I'd like to do an injector upgrade anyways, but I'm not that familiar with what's involved?

View user's profile Send private message
Display posts from previous:
Reply to topic Page 1 of 1
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum