I am have a 77 302 and its kind of mis-firing

It doesn't do it all the time just depending on the Rpm ,just Intermittently so I know its not a valve

It sounds like a small pop, and if I rev it up it gets louder but not as often.
I have a small exhaust leak, but I don't think it is big enough to cause my problem....

I bought the truck in september and it sat for 2 months before I drove her home.

I first started her up and had to adjust the timing because it was way off and I had a 4 hr drive to my house.
So after I got her running good (set timing by ear) and drove her up, I only made it halfway and then found out the gas gauge was stuck.
I ran out of gas & sat in the cold for hours trying to figure out what was wrong...
I put some gas in the carb and vvrroom... Got home ok.

A week after that I replaced the spark plugs and wires,cap and rotor.
It ran fine until one day I started her up and she started
mis-firing really bad again.
I found out that I had a bad EGR valve, so I took it off and blocked it off the port. She ran much better but still not the same.

I attempted an upgrade and it did not fix my problem. I put in a Power+Plus Intake and Edelbrock 600cfm carb, I got her running as best as a beginner could,


So, Once again I started on working with it.

I got a vacuum guage and everything else I needed.

I got her running almost perfect,

1) I set the mixture perfect

2) timed the engine with a light got it set perfect.

When I went to take out the spark plugs to see what they looked like, one of my plug wires broke!
So I grabbed an old wire and put it on so I could still start the engine to work on it.

I pulled all the plugs and they were black with carbon.

I am going to replace the plugs and wires again with better ones, Plus,I'll replace me cap and rotor again,but this time I am going with brass contacts.
Last time I did not know the difference,I just put a cap with aluminum contacts on because that's that it had.

I was almost going to replace the distributor, but I ran out of money and have to wait untill I get paid next.

Does anyone know what this problem could be?

Is there anyone else out there have a 77 302 that has had this problem ?

 

I got a little lost in your post but one thing I would check is the dizzy drive gear shear pin. Some times an older dizzy will start to drag and shear the pin but have the shaft seize again a few degrees later.

 

I did not understand what you ment by (and shear the pin but have the shaft seize again a few degrees later.) ???? What do you meen?Everything is running in great shape now, my engine does not shutter when I hear a pop, so I know all the cylenders are fireing at the correct time and all... I just went outside today and hoodked up the vacuum guage and set my mixture to get the highest possible reading, everything is in the normal, but as soon as I get enough cash I am replaceing the Dizzy, I think the vacuum advance is going out on it anyways, because if I stomp on it, it stutters (only somtimes tho) I believe it is sticking. But the next thing I am buying is a Dual Exhaust system, but I want to upgrade to headers later, is there a bold on system I can buy that I can swap from manifilds to headers without alot of trouble? Or should I take it to a shop and have them put a system on and when I want to upgrade to headers I can just take them to the place and have them do the swap? Because I know a guy who did that on his truck and it cost him an arm and a leg.... He told me to do it myself because its not worth paying somone else the labor..? I dont weld and dont have access to a welder..... So I would nee a bold on system, can anyone recomend anything?

 

I was having similar problems with my F350, every now and then it will make an assortment of noises that will stop your heart cold. Apparently, trucks that haven't been used much like to make noises when they are started to be used again. Continue to run that truck and I guarantee that you will find more of it. Same thing happened to me - started at the carburetor - six months later - still having problems. About the headers, I was going to do the same thing, hedman headers and a custom dual exhaust. I looked at catalogs to buy kits for the exhaust, looked at flex line so I didn't have to put bends in, stainless steel pipe. I finally decided to get a bid, $540 just for labor & materials, not including the headers ($250) so I just canned it and decided to put the money elsewhere and have not looked back.

 

Colossus, these posts are almost a month old! If the user was still having that problem they would have replied to their own post with something like "Anyone??? "

btw, please turn on your email function.

 

I went back to the shop today and took back the distributor I bought the day befor and the plate didnt move for the advance. and they gave me a rebuilt one (with single vacuum advance) unlike the other one. So I installed it after about 1hr tinkering arround with the oil pump shaft.... damn thing slid out with my dizzy and almost lost it .... Had to search for it with a flashlight and then I got it and put her back in... Thank god... But I put in my new dizzy and figured I would start fresh, instead of installing it where the marks I made were, I took out my #1 and found TDC and put her in so I can adjust it good both ways and I wont hit my water neck/radiator hose with the vacuum advance (that sucks and it looks retarded)so my vacuum advance is in line with my engine, new/rebuilt dizzy and clear cap match the new polished intake and edelbrock carb very well. It all looked good so I figured I would try to start her up, got in turned her over and Vroommmm.... jumped under the hood to keep her from dieing and adjusted the timing a bit (by ear) (light comes tomarrow when I drive her over to somone who has one) and she ran strong and great, hooked up the vacuum advance and gave her some gas and let off suddenly..... no pops or misses. I am one happy camper! I love ford and all of there die hard relyable trucks. Also I am beting I will get much better gas mileage out of a rebuilt dizzy and especialy since I have my advance hooked up! Next thing to replace are my plugs and wires. Maybe even some new valve covers to make everything prety .If any one has any recomendations as for what spark plugs or wires I would like to hear them. I am not puting champion in my truck tho.... I did that and it ran like crap.... So I clean'd up the old autolights and put them back in and they are much better. And as for wires, I want somthing under 60$ but not somthing that sucks... Any ideas?

 

Glad to hear the new Distributor worked for you! Sounds like you got the right one this time.

For plugs use Autolite.

For wires use Motorcraft. They have a finished OEM look to them that others may not have. The Motorcraft wires will go 50,000 miles or more b4 replacement.

 

I have always liked Bosch. For wires, Excel makes a wire kit can be had for under $40. Use to have to use these in the fireterd I used to have because it put off way to much heat.

 

Glad to hear it's running good for you, Dave. Now it's time to have some fun with it... doing things you want to do as opposed to things you "have" to do.

 

Motorcraft, plugs are your best bet. woody

 

sweet.. I got some new autolite plugs, and as I was installing them I pulled off the #3 plug wire and the connector came out of the boot and was stuck on the plug..... Nice wires eh? I dont know what they were but I had 4 choices to chose from and I got the #2 choice for 60$.... Too bad I didnt save the box or I would know if they had a warntee...... Oh well.. I went to my parts store today and they said I can only get the motorcraft plug wires from ford? How much are they going to run me?

 

Try a different parts store.

I just love those parts store guys that figure if they don't have it, -then it must be a dealer only item...

 

Bingo! I went to National Auto Parts (the best place in the world in my opinion) and I know 2 of the guys there (from always hanging around and askin questions) and I said I needed motorcraft plugwires and he said "is that it?" I said yep and he said come back in 1 hr ill go drive to the delarship and get them. I said ok and came back in 1 hr and he handed them to me and I said how much? He said well.... it says 66.72 ... but... thats to much.... give me 45.72... and then he goes wait..... nevermind just give me 45.... And then he said oh and by the way, as long as you dont burn the wires on the manifold they have a lifetime warente.... I said " I didnt think ford did that?" and he said "they dont we do..." I was like sweet... So I walked over to the engine spiffing up section (chrome watter necks, brackets and carb spacers) and was lookin at a wire loom for my plug wires and bought a nice shiney one for 21.00...Now I know why my uncle stands by them, they also have a damn good machine shop from what ive heard..... I told them about everyone at Shucks and they said "You know what Shucks is good for?" I said what. and he said " Anything to make your car look or smell nice - Cleaners, air fresheners, floor mats, and steering wheel covers." And when I thought about it, and out of everything that I have bought there thoes were the only things I havent taken back... So I went home and put the new Motorcraft plug wires and Autolite plugs in. Started her up and she ran like crap !!! I was like what the hell!!! So I thought I must have put a wire on the wrong sparkplug... So I whiped out the manual... nope.... (this was the same thing befor I replaced the dizzy) So I did the same thing that fixed my problem befor (unhooked and pluged the vacuum advance) Started her up... Vrooommm runs fine..... With no vacuum advance? I dont know what to do now? It runs great with no vacuum advance hooked to the dizzy... I am totaly thrown off... I drove her to the parts store to get somones opinion and one guy asked do you have EGR? I said I useto but I bought an intake that didnt have it so.... And he said he has done the same thing to his mustang and it runs bad with the advance hooked up and runs fine but uses alot of gas (town driving) without it hooked up. And mine gets alright mileage town driving and Exelent on the freeway, I went 130 miles on 1/2 tank of gas... And thats with a 600 CFM EDL Carb with Power+Plus Intake and 1" carb spacer..... I still havent calculated my MPG but its hard to when I only need to drive 5 min to get to everywhere...

So does anyone know what the heck my problem with my vacuum advance is? I have tryed adjusting it and everything?I just dont understand? I have hooked it to every port possible? And still the same or worse results (random missfireing)????

 

The best place to hook up the vacuum advance is on the tree on the intake manifold in the back. I do have to ask this question because it has happened before; Did you disconect the vacume advance, plug it and run the motor to 2000 rpm and time it?
Neighbor down the street had similar problems and he forgot to disconnect the vacuum advance.

best of luck.

 

I don't know how far you are from pittsburgh Pa. and I don't know it it can be shipped easily but I have the dual exhaust system off my 76 f-100 2wd 302/c4

I upgraded to a 351w and put bigger dual pipes on it, so I have the old pipes laying in the back yard. they went to the stock manifolds. You can have them if you can get them.