Running Rich or Lean?

[FordF350Baby]

I recently had to unplug my battery and I think I my computer on my 1995 F350 forgot its idling. When I got the performance camshaft installed the shop had to raise the idle because it was idling to low, but i think now that i disconnected the battery it lost the higher idle they put in. Also on another note, my check engine light has been coming on before this, and black smoke has been coming out of my tips, and i think its the oxygen sensors are bad or something because i gutted the cats, is that possible? Could that also be causing bad idling?

 

[blacksnapon]

I recently had to unplug my battery and I think I my computer on my 1995 F350 forgot its idling. When I got the performance camshaft installed the shop had to raise the idle because it was idling to low, but i think now that i disconnected the battery it lost the higher idle they put in. Also on another note, my check engine light has been coming on before this, and black smoke has been coming out of my tips, and i think its the oxygen sensors are bad or something because i gutted the cats, is that possible? Could that also be causing bad idling?

UH, the performance camshaft is causing the poor idling.

 

[d-kuzmen]

What codes do you get? There isn't a way to learn a higher idle. There mabe a screw on the throttle body that you might be able to tweak to bring it up some.

 

[FordF350Baby]

O really? They made it sound like they had to raise the idle through the computer, anyway howcome it idles so ruff now? Theres alot of variables here, I just replaced my midship fuel pump, I also disconnected the battery terminal for that job, my Check engine light has been coming on and off, and my idle has been low with black smoke.

 

[d-kuzmen]

We really need to know what the codes are. Also are you running off the mid ship tank? Does it run any better off the rear?

 

[blacksnapon]

Depending on how "competition" your cam is, they work by increasing valve duration (how long they stay open), and valve lift. The down side is that they also increase valve overlap (how long both valves are open at the same time). Excessive overlap reduces the amount of vacuum developed. Less vacuum=poor idle. Less vacuum will affect the hvac mode door functions as well. You might notice a decrease in braking (less vacuum for the booster). I've known guys that had to mount an auxiliary vacuum pump to compensate. The camshaft will affect computer functions as well. Installing a competition camshaft is not just plug and play, theres more work to do to make it street worthy.