2001 5.3 dead cylinder

[Matt Vardaman]

I recently bought an 01 Silverado and it had been setting up with a blown head gasket. I got the heads rebuilt and reassembled the engine with all new bolts and gaskets. I fired it up last night and my number 2 cylinder is dead. The coil, wire, and spark plug all test good. I believe it’s the lifter on the exhaust. It pops erratically out of the exhaust system, which makes me think the fuel is igniting late and blowing into exhaust. What’s the best way to verify for sure that it’s mechanical failure of the lifer? Anyone run into this? 

[Matt Vardaman]

Also this truck is in the limp mode which makes it stay in second gear. I’ll have to read up on the correct way to diagnose this separate problem. This truck is frustrating 

[sefiroxx]

Compression test, if no pressure , then valve is stuck open.

[Matt Vardaman]

Update:

I ran the engine with the valve cover off to verify valvetrain movement was correct. Compression test showed great compression across the board. Pulled the fuel rails and the fuel pressure regulator had disintegrated stopping up the number two injector. I went ahead and replaced all the injectors when I replaced the regulator. The engine is running great with rebuilt heads and new bolts and gaskets everywhere. 

 

Still have the limp mode problem, reading all the information I can find about it, have started diagnosing the problem, but haven’t found it yet. I have the wiring diagram. 

[sefiroxx]

Limp mode, usually, either:
- sensor signal to the ecu is way off. Use a scanner to see if anything is off
- transmission is reporting a problem, or is not getting any signal from the ecu. (Default setting is 3rd gear)

[dtnel78]

Changed the oil since you did this work? Unknown history on the vehicle prior to you getting it you may want to make sure that's done as well. I know this isn't related to limp mode just recommending. 

 

What's the codes on the engine? Check all your connections, grounds, etc as it could be something simple.