well i have an 85 f150 runs great until i put it in gear has new cap rotor plugs etc its backfiring into the intake as soon as i start to go what should i check next please help this poor old fool out

so when i put it under a load it spit and sputers backfires into the intake so now what should i do

 

Sounds like a timing problem, either ignition or valve timing (Timing chain jumped) Also check to be sure the sparkplug wires were installed on the correct sparkplug

 

well i thought i had timing all correct that seems to be otay still backfiring into manifold ugg shouldve gotten a diesel at least i know diesel sytems lol

 

Remove #1 plug and bring #1 cylinder up on compression stroke and see where the timing mark is located on the vibration damper in relation to the timing pointer, if it is not close to TDC mark then problem is timing------------------------ did this problem start all at once or steadily get worse? If all at once probably timing chain

 

its a new engine all seems to be pretty right on

 

I'm betting you either got the rotor on wrong, the cap rotated or the plug wires crossed if i started this after the tune-up. I got a cap one time that the markings were wrong on it and cost me about 4 hrs trying to figure out that the #1 marking on the new cap was in the wrong spot.

Hope that helps.

 

probably need to rotate the distributer 180, has to be something with timing if the engine is new. check the firing order, good luck

 

Look at this, bring #1 up to top dead center, check that the damper matches zero then take the dist. cap off and look at the alignment of the rotor to the #1 post.
It must be aligned to at least the center 1/3 of the rotor terminal, if not when the computer changes the timing it can fire to far off and jump to the next post and causing the back fire that is actually firing the next cylinder with it's intake valve sleightly open.
These engine are batch fire injected so fuel is present early in the intake cycle.