Hello all,

Need some help. Just replaced the knock sensors on my 2003 Tahoe 5.3l. While completing the project i go to start the truck and it won't turn over. I noticed some fuel spitting from the fuel rail on the right side of the engine so I replaced the o-ring and it has stopped leaking. I was thinking I didn't connect something but I have gone over the engine a hundred times with no luck. If I had to guess I would say there is a fuel issue because it cranks but just won't turn over.

Any Ideas? thanks in advace!

Joe

 

Project? What has been done?

 

The "project" was the knock sensors and manifold gasket replacement. Apon completing, the truck wouldn't start. Since then I have gotten it started but it now runs horrible and idles sluggish and wants to stall. When I remove the vacuum line to the fuel pressure regulator it seems to go to a normal idle for a moment before going to a higher RPM. I am not thinking the diaphram is torn and Fuel Press Regulator needs to be replaced.

Any Ideas anyone???

Joe

 

My EXPERIENCE with a fuel regulator is LOW idle speeds. I'ts about a $40-50 item easy to change.

 

ok, got it running good turns out both o-rings needed to be replaced on both sides of the fuel rails. now just have to solve my code P1518 problem!

 

That code has to do with throttle control missing data. Reset the ecm. See if it goes away. I wouldn't be surprised if that had to do with the O ring problem.

 

I reset to code and it has yet to come back although there is a decent in RPMs when I am at idle. Usually it idles around 1k-1 1/2k RPMs when idling but now it ranges from 5-800. everything seems normal though, just a really low idle RPM.

 

Idle should be around 800. As I stated earlier MY experience with a fuel regulator is low idle such as 4-500. If there is still an issue it will come back.