How would I ad fuel ? Bigger injectors or up the fuel pressure some how ?

 

The computer will automatically adjust the fuel to accommodate air mods, to the extent of which it is capable to do so. The stock system will support 250-275hp with no outside changes. If it is lean, and you have strong fuel pumps (no drop in fuel pressure that would cause lean), the next step is a bump in fuel pressure via an adjustable fuel pressure regulator or larger injectors combined with tuning software to calibrate to the new injectors. The former is much cheaper than the latter.

 

so I put a wide band in today and it's running on the lean side on the highway, 15-15.5 should I be worried? Is there an easy way to get some more fuel in there?

 

I'm not entirely certain and hopefully someone will correct me if I'm wrong; I think you can use a SD 460 computer and 24lb injectors from a 460.
Provided you get one that will work with your transmission.

 

Sorry to ask the dumb question, is that reading in the 15s at wot? What rpm?

 

Indeed you are correct, I've been running 460 comp and inj in my 89 for quite a long time now.

 

That is the most important question of course so this reply is directed at the OP.. an A/F ratio should always be accompanied by the conditions under which it is achieved, otherwise it is useless information. 15:1 AFR while cruising under light throttle is exactly what these trucks were designed to do, but if that is with the throttle wide open and accelerating that is not at all acceptable and suggests a weak fuel pump.

And did you calibrate the wideband system during the install?

 

that's crusing on the highway. I took it out again last night, it got pretty close to 16. When I accelerate it goes down to 12-13. No I didn't calibrate it. The instructions didn't say anything about that. I'll double check though. It's an auto meter gauge if that helps ... I haven't changed the fuel filter in the year that I've owend the truck. It's kinda stuck on. I'll try again today

 

The computer can normally easily adjust cruise and light throttle conditions to the target afr regardless of how far from stock the engine is, as a small change in duty cycle goes a long way under light load conditions.....it's the heavy pedal high load wot where the stock injectors, even at high duty cycle, cannot keep up. Watch the afr at wot for a long 3rd pull and see if it starts to creep up to lean as rpm increases. If so, tuning of some form is required. If it stays in the 13s to red line, you have nothing to worry about.

 

The EFI system is working as it should then, you would only have a fuel delivery problem if the AFR goes lean when accelerating at higher rpms.