351m - Ford F150 Forum

pgf150 · 05-17-2007, 05:30 PM

I have a 1980 f150 with a 351 M and all the vacumm hoses off the carb are unhooked and can anyone tell me where they go? It runs good in park/nuetral but as soon as i **** it into gear it runs ****yy

NGM · 05-17-2007, 06:03 PM

I vacuum line will run from the distributor to a ported vacuum on the carb. this is a port that only has vacuum at idle. Once off idle it will lose vacuum.
One should go to some sort of vacuum tree. Off that vacuum tree is the vacuum for the dash. There is a main vacuum line from the intake to the brake booster. Hope this helps. IS it the stock carburator or aftermarket?

pgf150 · 05-17-2007, 09:06 PM

its a rebuilt carb that i bought from the local autparts dealer

NGM · 05-17-2007, 09:09 PM

So basically its a stock replacement. As long as your dash components work and you attache a vacuum to the distributor and of course to the brake booster, you should be fine. The rest of them can be plugged off.

pgf150 · 05-18-2007, 01:02 AM

k thanks sometimes it'll run good when i first start it for about 30 seconds then it starts backfiring out of the carb and exhaustand has power unless in 1st gear and 4Low

pgf150 · 05-19-2007, 12:10 AM

doesnt have enuff power to even move unless in 4 low 1st gear