Vortec 305 running super lean

[ralmo94]

I think the only thing left then is injectors. They can be cleaned and new orings installed. Also you mentioned fuel pressure under load, so I don't think it's it, but what about fuel filter?

 

[nauju]

I think the only thing left then is injectors. They can be cleaned and new orings installed. Also you mentioned fuel pressure under load, so I don't think it's it, but what about fuel filter?

It has brand new injectors and new fuel filter

 

[ralmo94]

Seems just about everything is ruled out.... I really don't like to suggest this ever, but can you possibly swap another pcm in for diagnosis?

Just making sure all things are covered, stock replacement injectors used?

Do you have any way to Data log?

How did you rule out vacuum leaks? As what method?

 

[nauju]

Seems just about everything is ruled out.... I really don't like to suggest this ever, but can you possibly swap another pcm in for diagnosis?

Just making sure all things are covered, stock replacement injectors used?

Do you have any way to Data log?

How did you rule out vacuum leaks? As what method?

They are the better style injectors and I currently have no way to data log, I ruled out vacuum leaks by spraying brake cleaner all over the intake and vacuum hoses

 

[ralmo94]

I ruled out vacuum leaks by spraying brake cleaner all over the intake and vacuum hoses

It can be inconclusive in EFI, to be sure you don't have a false negative, you should unplugg o2 sensors and IAC. I would also do that on a fresh reset after unhooking the battery. Can be hard to spot with IAC compensation. You might look up propane method, supposed to be a lot safer than starting fluid and doesn't ruin rubber hoses.

They are the better style injectors

Was it lean before the injector swap?
They could have a different slope time than the stock ones. I'm not real familiar with the 305, but if they are a different lb per hr, that could definitely cause a lean condition.

 

[Dropped88]

Also where are the injectors from I've seen some of the cheaper options not flow the proper amount

 

[nauju]

It can be inconclusive in EFI, to be sure you don't have a false negative, you should unplugg o2 sensors and IAC. I would also do that on a fresh reset after unhooking the battery. Can be hard to spot with IAC compensation. You might look up propane method, supposed to be a lot safer than starting fluid and doesn't ruin rubber hoses.

Was it lean before the injector swap?
They could have a different slope time than the stock ones. I'm not real familiar with the 305, but if they are a different lb per hr, that could definitely cause a lean condition.

It was lean before the injector swap

 

[Schurkey]

I ruled out vacuum leaks by spraying brake cleaner all over the intake and vacuum hoses

DO NOT use brake cleaner to check for vacuum leaks.
1. Some brake cleaner is not flammable. If it doesn't burn, it doesn't give a reliable indication of a leak. Best you can hope for is the liquid sorta-kinda reduces the air flow through a small leak.

2. Some brake cleaners produce poisonous gasses when burned, this can cause long-lasting nerve damage or even death.

I use carb spray. Some folks use propane or starter fluid. The carb spray cans come with a red "straw" to direct the spray to a very limited area that I find more useful than propane or starter fluid.