Ok, my 420a keeps stuttering when Im under 3 grand, and sometimes at high speeds, it feels like a plug isnt fireing, but I replaced the plugs and spark wires, even tried dry gas. Idk what it is, I know it can be many different things, but anyone have ne ideas.

 

does it idle ok?

 

check compression.

 

It idles fine, but then it will some what "skip"

How i check the compression?

 

im pretty sure you can buy a compression checker thing at any parts store...im not sure, i borrowed my friends when i checked mine. It just screws into where a spark plug goes, and you turn it over for a few seconds. you should unplug 1 or two other plug caps too just so it doesnt start on 3 cylinders.
I cant remember what good compression is...someone on here will know...

 

ok....Think it could be idle timing or timing belt? has 75000 miles on it...

 

Ok, so I ran it home from my buddys house...and it didt do it til half way home? Like when it finally got warm? For some reason I think its a fuel filter...

 

that would be a good thing to check (fuel filter).

 

Can someone tell me where the fuel filter is?