My 351m has a new intake manifold and a holley four-barral carb on it. I was wondering if there are any vacuum diagrams available for this? i bought the truck not running b/c the motor(not origonal) was not completly hooked up(carb, & wiring). There was previously alot of little gadjets that came with the stock setup that im not shore what there purpose was. now im not sure where to plug in what. so far its running alright after changing the vacuum lines around until it ran its best, but it doesn't want to run smooth unless i play with the choke, even after its at normal opperating temp. Im pretty sure the vacuum is the problem, any advice/help is appreciated.

kevin
1980 F-250 4x4

 

how much of the emissions junk do you have still hooked up? (egr, air pump,ect.)
i scrapped all of mine so the vac lines are minimal. 1 line from dist. to spark port on carb. at the passenger side rear of the manifold mine has a vac "tree" that screws into the manifold. off this tree-1 line to the power brakes and 1 line to the automatic trans. the only vac lines left are for the pcv system. mine runs great like this. could post some pics in my user gallery if you think it would help. or try using the search feature in this group. good luck.

 

i found some helpful info on the holley.com site under instalation instructions. I also read through the haynes manual under emissions chapter and leared a bunch of stuff that helped me understand how the vacuum mess worked.

 

i probly wouldn't have thought to look through the emission section if it wasn't for sparky69. Thankx

 

did you get it running good yet? surprised no one else helped out.

 

I did get it running alot better, but the only problem left is after it warms up it doesn't have a consistant idle. it runs smooth for a few seconds then almost stalls out(somtimes it does stall)Im thinking the timming might need to be fine tuned.

 

Some times a little help is better than too much, sounds like you have made progress. What condition is the carb in?? If it is of an older era like the one I have on my 351c it might just need to be scrapped, rebuilding is not even an option. You might want to check and make sure you have good manifold vacuum. Sounds like it might be flooding out(floats too High or bad needles and seats) Good Luck
DD