1978 Ford F-150 Cammed 351M

[@davidkehn6960]

My 78 f250 camper special, round headlights.

[@michaelhaslett3742]

Sure you have already fixed this by now but mine was the fuel filter on the carb. Doing the exact same thing as yours. I put a new fuel pump, new distributor rebuilt the carb put a electric lift pump to help the mechanical pump and it still would get warmed up and stall. Thought it was vapor locking so went through and put new fuel line in the engine bay all wrapped thermally and it still did it. Last thing I did was remove the metal fuel filter on the carb and haven't had an issue since.

[@gregoryhathaway4586]

I had a problem with stalling for years, and I finally discover it was the magnetic pickup in the bottom of the distributor. It would only cause problems under load or acceleration. Cost like 10 bucks. However, since you may not have the normal distributor this may not be the problem. Another problem I had with mine for years was the brake booster would draw down engine RPM when pressing the brake hard. That turned out to be the check valve installed backwards on the vaccuum advance. I discovered that by looking at pics in a book!

[@alanmeyers3957]

This is points, so no magnetic pickup.

[@iangoolsby]

That check valve would only be on ported vacuum. I run manifold.

[@karlslomchinski1827]

I have the same truck for 30 years. I fixed my stalling problem, it would not start when hot. It was the pick up coil in the distributor.

[@fukkdasystemxd3759]

I once bought my first ford truck it was a 74 F250 and now I have 12

[@jesiahjakob2180]

You probably dont care but if you're stoned like me during the covid times then you can stream pretty much all of the new movies and series on instaflixxer. Been binge watching with my gf for the last weeks :)

[@omarikobe6629]

@Jesiah Jakob definitely, have been watching on instaflixxer for since november myself =)

[@ghettosled1976]

First I’d check is your accelerator pump on your carb if you’re having issues when you hit the gas hard. Then timing. Then air fuel mix.

[@alanmeyers3957]

I was going to say purple wire, but the box is gone, you need a ballast resister from ignition to coil.

[@wyattwerfel2875]

The 2bbl carbs are harder on gas that a good tuned 4bbl

[@thomaswilson117]

You might want to think about going HEI. I bought an HEI distributor for my 351M and I love it. The one draw back is that you need to buy a separate pigtail for it but it isn't expensive.This pig tail will also have a hook up for your tach. I think Fordication has all the wiring diagrams for all the 70's models.You can trace the red run wire off the ignition switch.

[@patrickmacord8725]

Thomas Wilson , Are you running the Mallory HEI Distributor?

[@thomaswilson117]

Patrick, Not going to lie, I went cheap. I bought an Assault HEI by KMJ. I was skeptical about how good the HEI would work so I bought something that wasn't too expensive so I wouldn't be out too much if it didn't work. Never tried Mallory but if they are anything like KMJ's, you should be able to buy Chevy rebuild kits if they every fail way down the road.

[@davidbabkoff2985]

I'm running the HEI on my 351 and I love it runs grrreeeeeaaattttt

[@obsessedwithcars219]

Love the sound of that. I also have a 2 barrell motorcraft and I love the way it performs

[@vernonknight5827]

It falls on its face because of valve float. Replace the valve springs

[@fordinlinestraight]

I just picked up another project its the same thing 351 m but she aint running good

[@cvfdchief9]

Previous owner didnt bypass anything, they installed an earlyer points style distributor, connect your tach to the negative side of the coil...the same that goes to the distributor

[@robertgabelucio6647]

Hey man I feel you. My ol girl is a 79 f250 with the 351m. She doesn't like to idle she runs like a champ until it i come to a stop. And it sounds good. Now I really want to slap a nice cam in mine, more than before.

[@josephseibert4662]

It could be something in the tank or in the fuel lines I had a truck run great if you were easy on it no trouble soon as you hammered it it would die everytime I ran new gas line from tank to carb and it fixed it the carb had a bunch of rusty stuff from the gas line literally Rustin apart from within

[@leadbullets4life]

sounds like you need to adjust your float it may be a low bowl causing you to stall out due to lack of fuel when you stomp on it the bowl empties out before it can fill up and or fuel pressure is too low caused by a weak fuel pump or worn accelerator pump diaphragm.

[@davefuckinharris]

Sounds great! ! Kinda sounds like it may be low In time

[@ghettosled1976]

Probably not the first to tell you not all ‘78’s had square headlights…. But if I am, now you know. Also, M does not stand for modified. It’s just M. And also, also: these engines barely flow 350cfm without extensive head work, so “I wish it had a 4 barrel” would make it perform worse, not better. That’s why they all came with 2 barrels

[@josephdeffendoll3056]

The head liner is from jc Whitney catalog. It cost 600.00 alone. Nice truck

[@fordinlinestraight]

Cool old truck

[@dennislockhart1972]

My 78 had a similar problem it was the fuel cap didn't have a vent, it was vapor locking. The truck wasn't overheating or anything, just when it was hot out it was building up the vapors but nowhere to go, now it runs and starts no matter how hot it is outside.

[@fordinlinestraight]

Tach green wire goes to positive side of coil. On mine I use the 12 volts from the cigar light for the red wire then ground wire I found good place under dash and green cable put thru fire wall to coil. I would definitely put that module back! He must have switched the distributer at some time to a points and condenser. Or other possibilty is he put the icm some where in the truck

[@fordinlinestraight]

Also check all vaccum lines. Choke should be fully open when warmed up

[@nathanschuchardt2593]

I agree. Go with an hei distributor. Get the timing right and you'll have no further issues. If it misses out at top end, your "total" timing is too advanced. Good luck!

[@redneckred9512]

Nathan Schuchardt I would adjust the timing but recently I did a compression check and one cylinder is dead only 10 psi and now tons of blowby gonna replace engine

[@richmarks726]

Sometimes coils get hot and break down mite check that

[@Catboy.]

I have a 77 f150 with the 351m and I picked it up for $300

[@redneckred9512]

Since making this video I have removed this engine and replaced it with a crate engine no problems now runs great I made a video of it check it out it's on my page thanx everyone tho for all the tips

[@jrvenatkinson7550]

Took the filter out the carburetor on my 79 runs good now

[@Terminxman]

I bought a carb spacer and wrapped my fuel lines with some heat shield stuff. It pretty much fixed the hot start/hot idle problem. Luckily I've never had vapor lock completely but it's still annoying as fuck. I ended up removing the carb spacer though (it's called CoolCarb) don't buy it because mine started leaking and when I removed it the inside of it had started disentigrating. So now I'm back to square one, debating doing an electric pump. I'm gonna try some ethanol free gas too. Also I have a hard time believing the corvette story unless you blew past him and he didn't know he was racing.

[@mschiffel1]

Fuel pump's crapping out at highway speed.

[@1963impala2drWaylonWire]

sounds pretty healthy

[@danderson9881]

set up a Gm Hei module, simple wiring, and hot spark

[@mschiffel1]

Get yourself a new HEI style distributor. All self contained and just a one 12V wire is needed. Check fuel pump pressure and float level.

[@colby1380]

I ended up changing the alternator because the old ones suck and when they get over driven they cut power to ignition so when I upgraded to a 3g it barely stalls now but it still stalls some

[@redneckred9512]

Colby Pettigrew this spring I dropped in a new 400 crate engine runs like a dream now no more issues

[@jimmorrison1553]

Upgrade to GM HEI distributor. Use that wire to the starter as your input and then use the tach output on the distributor.

[@redneckred9512]

Thanx for the tips I'll give em a try

[@RussellBrosGarage]

We are workin on a 77 Stepside F100 w/351m

[@gearhead9943]

I'd love to see a cold start from inside showing us how rough it actually starts. How many times do you usually have to pump it? Would love to see!

[@travisdoedoewhitaker1947]

My 77 4x4 starts first time and idles by itself 9 times out of 10 on it's on.

[@skylarcataldo8723]

@@travisdoedoewhitaker1947 cool

[@israelmoreno3620]

77 was the last yr for the round lights i have a 77 super cab with a 78 grill im looking for 77 grill im installing 1406 carb with a 2166 intake to with the mighty 460 love her video is up if yous like take looks your truck is a amazing i was looking for 250 high boy cant find em i got lucky i found my big gurl

[@jameseanes7192]

That thing sound damm gud

[@trucksntractors7160]

check for a fuel boiling issue, I have had it be a problem many a many times on my 77 ford and my 79 Blazer

[@redneckred9512]

Trucks nTractors yeppers that be my problem fuel keeps boiling after a long drive or idling too long lots of heat from the headers I replaced fuel filter and pump, mechanical, going to try some header wrap see what happens also contiplating an electric fuel pump

[@trucksntractors7160]

I have all that plus the 105° ambiant heat issue from living in south Texas working against me.

[@colby1380]

I had the same exact problem with my Bronco

[@oregonfordguy9812]

someone who knows the 351m vs a 400. liked the video just off that.

[@IsaacSchuler]

nice truck

[@redneckred9512]

I will make one soon

[@MyJm29]

i have 1981 351m f350 dually and i had the same i rebuilt the cab reset the choke and set the timing i think its the choke mine starts like a new motor. try missing with the choke and the carb

[@StroudWorshipTeam]

Definitely a good chance of being the choke. From about 76-86 they were not the greatest chokes especially on the 351m.

[@Porchhonky]

Your exhaust could be to open. If you are running straight pipes try putting cones in your header/manifold. If you dont run straight pipe then it's the carburetor. Too much air and not enough fuel and it is choking itself out on the backstep

[@mitchseibert1484]

Early 78 f250s came with same grill.. I got one that's factory. Nice rig great potential

[@BuzzLOLOL]

My '78 F150 Custom has round headlights...

[@ohnojt]

from what I understand, and what I have always been told, they switched to the squares about half way thru 78.

[@oregonfordguy9812]

@@ohnojt nope. the 78 round headlights 2was a custom trim level . all other trim levels got sqqure and all 79s were sqaure . always a big debate in the 70s ford pages.

[@christophereaves862]

What cam do you have ?

[@gimplife8010]

Rust in tank. Filter at carb

[@jeep2nv92]

Did you ever fix the stalling issue? Mine did the same exact thing. My issue was the mechanical fuel pump. It wasn’t pumping enough fuel. If I drove it hard, it would suck the carburetor bowl dry and stall.

[@redneckred9512]

N8 Morehouse unfortunately no I didn't I replaced my mechanical fuel pump with a new one still same issue I'm not sure if it's vapor lock or possibly timing is off it does have a dead cylinder so it could be that I'm in the process of buying a new engine for it should be done soon

[@opusd2]

If the tank had older fuel in it or maybe the tank is just rusty inside, set yourself up with a couple of see through fuel filters where you can change them easy enough. My 78 had your problem and that's what cured mine. If it doesn't work you tried

[@Fatalimit]

Power valve maybe? for your stalling issue

[@mikekissner7894]

Timing is a tooth off and you have a serious vaccuum issue

[@TheFrameoff]

that's look like a standard distributor not hei and the chrome moulding on the box is not 78 it is earlier

[@redneckred9512]

Wow just wow this guy deserves an award of some sort enlighten me bud when did I say it was a hei? Lil bit of advice watch videos more carefully and get all the facts before you start acting like you know it all

[@TheFrameoff]

Hey I didn't say you did , just curious because the truck seemed to be assembled with different component's like you said the front clip looks to be 76 , the steering column looks to be around 76 . 79 had the plastic that covered around it and the 79 had the wide chrome mouldings with the rubber insert on the cab and box .. but like you said they are great trucks , owned mine from brand new and had a few that I have drove for awhile and stripped them for parts . Your stalling could be a stuck float , the float is not returning to it's proper position and when you hammer on it drains the float bowl and then slowly refills so you can drive it normal .. just a thought

[@patrickmacord8725]

Are you running the Mallory HEI Distributor?

[@sorshiaemms5959]

check for a vacume leak

[@fishhogz6982]

That’s not a 78 it’s either a 76 and a half or a 77..

[@redneckred9512]

It's a 78 with a 77 grille I said that in the video

[@fishhogz6982]

@@redneckred9512 ahh sorry for the inconvenience lol I didn’t hear that part

[@oregonfordguy9812]

@@fishhogz6982 no such thing as a 76 and half anyway

[@fishhogz6982]

@@oregonfordguy9812 your fucking stupid then

[@thomaswilson117]

Also, check the fuel filter and see if it is clogging bad. I know that has caused some of my old trucks to stall in gear but not on idle.

[@porkininc.634]

What mufflers and pipe size are you running?

[@flamertheboss8117]

What size cam are you running on it?