Hey everyone I'm new here this is my first post! I have a 1986 f150 with a 4.9l 300 cui 4 speed. It has an offenhauser 360 intake with a Rochester Quadrajet. Now i rebuilt the carb last week because all the jets got clogged and the float had too be replaced but after all that now it won't idle? I'm not sure what the problem is any help would be great!!!
Thanks

 

So let me understand, you put a 4 barrel carburetor on a 300? I have to admit I am a stock kind of guy so I do not have the experience to help. But assuming all things are right on the carburetor I would look for a vacuum leak or line disconnected. Exactly what was the problem prior to the carburetor rebuild. Just to give us a little history.

 

Yes it has an offenhauser 4 barrel intake on it. The reason I rebuilt the carb was that it was leaking through the top bowl gasket and the primary jets weren't spraying. After the rebuild if new gaskets and jets it still runs terrible. I've checked all vacuum lines as well. Is it possible that the carb has been rebuilt one too manny times and it just needs too be replaced?

 

i take it u did the whole duraspark conversion? and havent messed with anything else? rockers? vac advance distributer? hasnt overheated? etc no other goings on?

 

I'm not sure what the duraspark conversion is. I got the truck with the offenhauser and 4bbl on it already and it ran fine until the carb went

 

Well, the duraspark is the older ignition system before they started puting computers in these trucks, i believe your truckis the first year they put a computer in it. Generally you should have a vacuum advanced distributer and a seperate ignition box mounted under the hood or under the dash with a blue duraspark label on it. If not, i would start by finishing the conversion, which a simple google search will give you all the details. Second, check ur fuel filter and make sure its not gummed up too if you havent replaced it already. But troubleshooting the whole ignition system may reveal an issue that was hiding before you worked on the carb

 

Just looked under the hood this morning and it looks too have the blue durapspark module and vacuum advance dizzy. I have already replaced the fuel fliter and pump. I'm wondering if it's the carb. It has a quadrajet on it I was looking at the holley 390? What would you recommend?

 

Also I'm wondering if there's anyway too remove all the AIR injection stuff?

 

390 would be a good choice, but so long you dont drive it like a race car any 600 would work as well. by air injection i believe you are referring to the egr? in which case ya you should be able to pull all that out, just make sure you cap any vacuum. but that kinda opens up all sorts of other possibilities if you still have all that...

 

Okay and no I know there's the egr then the whole AIR injection system with the air pump and that rail that goes over top of the head