Need help. No start, has everything.. ready to smash
Thread Starter
On The Tree
Joined: Aug 2015
Posts: 155
Likes: 1
Need help. No start, has everything.. ready to smash 5.3 rebuild. I’ve replaced all the sensors needed. Crank sensor reading, injectors firing, has spark, pcm getting voltage on crank, fuel pressure constant... on the scanner I’m seeing all the right data.. no codes... no start. What am I missing? I am seeing the cam sensor not read hi to lo and lo to hi on hp scanner but I’m not sure if the 02 pcm OBD protocol can display that like can data does. I’ve replaced that sensor anyways and timing chain is not broken. I’ve copied over the data from a stock 5.3 tune as well as others and none of them will get it fire up.
What am I missing??
What am I missing??
Teching In
Joined: Jun 2011
Posts: 15
Likes: 0
Mods or changes to the setup helps.
understanding that it ran before the transmission was replaced , can an internal trans electrical problem cause this ? I'd actually like to know this .
other than that ....it sounds like the cylinders are washed down , maybe a few squirts of eng oil per cyl. ?
and how did that compression check go.
understanding that it ran before the transmission was replaced , can an internal trans electrical problem cause this ? I'd actually like to know this .
other than that ....it sounds like the cylinders are washed down , maybe a few squirts of eng oil per cyl. ?
and how did that compression check go.
Nothing inside the trans is going to cause a no-start condition for the engine.
Have you verified that the injectors are squirting fuel? Have you tried spraying carb, or brake, cleaner into the throttle body while someone else cranks the engine over?
I've built a few LS engines and it seems the injectors, when left to sit with old fuel in them will plug up in a short period of time. Not kidding. I've had this happen twice on two different builds. At least on the 2nd build, I knew why it would not start.
Also, pull a spark plug out, reattach the plug wire, and hold it against the engine while someone cranks it over.. Watch for spark. If no spark, at least you know where to look.
Have you verified that the injectors are squirting fuel? Have you tried spraying carb, or brake, cleaner into the throttle body while someone else cranks the engine over?
I've built a few LS engines and it seems the injectors, when left to sit with old fuel in them will plug up in a short period of time. Not kidding. I've had this happen twice on two different builds. At least on the 2nd build, I knew why it would not start.
Also, pull a spark plug out, reattach the plug wire, and hold it against the engine while someone cranks it over.. Watch for spark. If no spark, at least you know where to look.
