Here are the readings of my stft and ltft. I think I may have vaccum leak or a fuel delivery problem. The engine is reved up to about 2000 rpm's.

Here is the link. http://www.youtube.com/watch?v=SOgG29-hL6o

 

Does anybody have any ideas?

 

I think I have a vaccum leak somewhere, I think I might have leaking o rings on the injectors since I did use the old o rings. Or I have leaking intake manifold. The reason why I think this is because once the rpm's get above 3000 the engine runs normal and that is when the engine has a very small amount of vacuum. So the leak would not be detected because the vacuum wouldn't be strong enough to detect the leak. When i scaned the fuel trims above 3000 rpm's the fuel trims were normal, stft was at +8 and the ltft was at -9. So looks like I will be buying some cans of carb cleaner to find the leak.
Do you think this theory is right?

 

Thats a good way to check for vacuum leaks. All you can do it try and see.

 

I prefer an unlit propane torch. Doesn't leave the mess that sprays do and will also change the idle if there is a vacuum leak and it sucks in the propane.

 

Well I bought some super tech carburetor cleaner to use to see if I could detech a vacuum leak. When I was spraying the injectors I didn't really notice a change in idle but every time I sprayed the injector it bubble around the injector that I just sprayed. I don't know if that means that there would be a vacuum leak there or if it is just bubbling.

 

New video of stft and ltft warmed up. http://www.youtube.com/watch?v=72w1dk929WA

 

Im sorry if I forgot but at any point recently have you reset your PCM.

 

I reset the pcm by un hooking the negative side of the battery for about ten minutes. I also had the battery out of it for about a month a while ago. Would that affect the pcm anyway? Since I put this new engine in I haven't driven it more then 150 miles, do you think the pcm needs to relearn everything since it was un hooked for so long as hasn't been driven a lot since.

Do you think the fuel filter is clogged?

 

When you reset the PCM, everything the truck has "learned" must be relearned. This included fuel trims. This is why when doing custom tuning and after installing the tune, the truck must be driven for some time for the PCM to learn the tune and adjust its parameters (including fuel trims). It needs to learn the owners driving habits and based off those habits, your FT numbers may be normal.

The goal for tuning is for the LTFT to be at 0.0 which means the PCM is neither having to add or pull fuel. But the only time I have ever seen anyone bother with this is when it comes to custom tuning. I have no idea how a stock tune fuel trims are supposed to look. They obviously will NOT be optimized.

Sorry to ask but what is your issue again other than your FT numbers being off a bit?