cfi to carb problem

[kelligrew17]

Hey folks!hoping someone out there is familiar with this problem. I swapped out the cfi on my 85, and now it starts and idles just fine but whenever i pick up the throttle to(i'm guessing here)2500rpm the engine starts misfiring and idles very rough. when i kill the ignition and then restart it, it idles fine again. I swapped distributors and have installed the duraspark II control box. i'm stumped? have wired and rewired with the hayes manuel till i'm blue in the face thanks for reading! cheers terry

 

[90stang5speed]

what about fuel pressure? Im not sure how much pressure CFI uses but, fuel injection on a 90 modle is around 40 psi. carb cars are usually 5-10 psi fuel pressure arent they? Im not sure if that will help ya or not.

 

[kelligrew17]

cfi to carb

hi! I've taken the fuel pump out of the tank and installed an inline electric with the required pressure, thanks for the thought! i i've adjusted the carb, played with the timing all to no avail?

 

[Stever89]

My first thought was fuel starvation also, but other things could be a vacuum leak (hoses, tighten the intake and carb) or vacuum advance. Just throwing stuff out there, I also have a carbed motor.

 

[kelligrew17]

hwdy folks! I've had someone tell me i'm one tooth off on my timing, so when i hit the throttle the vacuum advance is tripping over the line? so i'm gonna give that try and double check for tdc. thanks very much for the replies, i'll post the results. cheers