Ok I know I need a custom prom it would be nice I could get my laptop to read my car again has not worked since February


Anyway here is the deal I have an 86 L69 305 HO crate engine
Lunati cam .455 intake .483 exhaust 205- 215 .50 duration major ported heads, 454 tbi unit 55lbs injectors installed on ported 350-tbi truck intake
Headman shorty headers ran pretty good with stock tune low 14 sec quarters at 96 mph

I changed the intake manifold to a weiand 7547 single plane blocked the exhaust crossover in the heads
Now it idles ok normal driving is good, however when I get on it
It will take off great than load up, and misfire about 2500- 3500
Than haul *** to 6000. Now here is the weird part if I drive it HARD for 15 -20 min it runs F**n great!

Should I pull the intake and open the exhaust crossovers or just plan on heavy prom tuning
I am thinking of just putting a carb on it and being done with it

 

If you want to stay with TBI you need heavy PROM tuning.

 

Maybe a fuel regulator will help out. The TDS one may be your answer but like everyone says chip burning is essential, just not for me right now.

 

That's funny that you posted this now. I just did an intake and header install on my engine. I'm using the Holley TBI manifold with EGR blocked off. I get the same bogging at the same RPM level you're saying. It just falls on its face at that range. I just figured I needed chip tuning that maybe its picking up some knock in that range and pulling a bunch of timing out. We'll see when I finally get the tuning stuff.

 

I have been without an EGR for years, I do have an adjustable fuel regulator; Holley 255 fuel pump seems to make no difference where pressure is set, I guess something about changing intake manifolds sent our engine calibrations over the edge-- I am thinking of pulling the intake back up today {It has a slight oil leak from the rear seal}
I am going to open up the exhaust cross over maybe fuel is pooling on bottom of intake when engine is hot problem mostly goes away
I wish I could still data log and see what the heck the engine is doing