Well I guess my old '82 F150 has had all she will take. Going to have to put her down for possibly a couple years.

Was driving home truck running great. Stopped at a red light running great with ac blowing cold. Hit the gas when the light turned green whole truck started shaking itself so bad the dash was trying to bounce out of the truck it was moving that far away from the windshield. Truck took gas so its not gas. I floored it smoothed out some and it took the gas but cruising there was a vibration and at idle there was a horrible vibration. I thought maybe dead cylinders. So I knew the engine burned a little oil from the heads having valve guides knurled back when the engine was rebuilt back in the early 90`s. So I figure replace plugs, 4 of the plugs had ash deposits on it but the gap was not blocked.

Anyways replaced all plugs same thing. So I got my tester out and tested each cylinder at the dist and all cylinders are firing but still running rough. Guess something in the motor is out of balance now so I guess now is the time to start trying to figure out what to do since I don't have the money to buy a engine right off the bat.

I'm looking at this BluePrint 302 HO mustang replacement engine for $1,699 which I might be able to get the cash saved up so I wouldn't wipe myself out in a few months. Problem is its a roller and I am pretty sure I will have to swap my gear on my dist to be compatible.

https://www.summitracing.com/parts/m...view/make/ford

But then I have to buy a new timing cover, new motor mounts, a new flexplate as mine had some grind marks on the face of the ring gear. So looks like I got a lot a head of me. Just wish I could find a reasonably priced crate engine that would make me 200 hp with the stock intake and 351CFM motorcraft 2150 2bbl carb.

 

Sorry to hear that.
You did a compression test show and what were the readings?
Could the harmonic balancer ring moved? Check the timing with the light would tell quickly.
Last thing I would do it pull the valve covers and check that all the rockers are working when running.
They are all easy things to check and fix (cheap) if you find it is one of them.
Dave ----

 

I would check the engine mechanically with a compression test before replacing it. If you have good compression, I would keep looking till you found the problem. How many miles since it was rebuilt? I would guess the timing chain was replaced back then, and hopefully not with a plastic coated sprocket.

 

Nope I didn't go any further than verifying all cylinders are firing. When I was driving home with it shaking if I floored her it smoothed out but there was still some roughness. Accelerating normally at 1500 rpm from a stand still it was horrible shaking the dash out of the truck.

The balancer ring moved, I don't know but I don't think Ive ever seen one move and cause a vibration like this.

I think the compression is fine cause when I went to crank her up after changing plugs, the engine spun over smoothly there was no dead holes where the engine tried to spin differently due to a change in compression.

I am now wondering if a balancer could cause this. It is a 50 oz imbalance but I want to say I changed it on this truck already when I did my timing cover housing. But I guess I could grab my light and see if the timing is just way off.

 

How did you check that all holes were firing?
I would still do everything I listed to see if something pops up.
Dave ----

 

I had a shaking problem like this on a car I had awhile back, and I could pump the gas pedal and it would smooth out. But hold the pedal steady and it had what seemed like dead cylinders. It turned out to be a piece of dirt in only one jet in the carb. You have two jets, one feeds one set of cylinders, the other jet feeds the others, since you have dual plane intake. When I was pumping the gas pedal, I was mechanically adding fuel to the engine and it would smooth out. I took the carb apart and pulled the jets, a piece of rust floating around the bowl had lodged itself in one of the jets plugging it up.

See if pumping the pedal smooths it out, but holding it constant makes it miss.

 

Well I went out and checked the timing just for ****s. I cleaned the balancer off and applied some fresh white paint to the 0 mark and used my adjustable timing light with vacuum advance pulled I moved from 0 to 50 degrees advance and didn't see the mark. Looks like the balancer has slipped on me.

Ive never had one slip and I wanted to replace the old one on the '69 El Camino at work the other day cause it had a groove worn in it, boss said he never had a balancer slip but hes had the rubber rot out. So I guess I will have to keep this in mind for next time.

With vacuum advance disconnected the engine was idling around 500 rpm and was almost dead smooth no vibration. I also noticed it looks like the weight is up at the timing point for cylinder 1 instead of the thin side that has the markings.

After seeing this I remember I replaced the dist a couple years ago and set the timing back to 12* and noticed my rpm was way too high and had to turn the idle adjustment down. Thought nothing of it. Balancer must have slipped a little then.

So I am hitting up advance right now to place a pick up order for tomorrow so I can pull it and replace it tomorrow.

When I got home I was thinking it feels like something is out of balance in the motor didn't feel like a dead hole miss to me.

 

I have one of those inline bulb spark testers I hooked it between the cap and each spark plug wire and it was flashing steadily and brightly for each cylinder I tested. This way I tested spark plug wires as well as spark plug themselves for spark.

 

well guess I will have to order it cause this ****ed up city here doesn't seem to have a balancer for my truck. Advance has none its a order item. Napa doesn't have them other than $200 performance balancers. Oreilly shows one but no spec on the weight of the balancer. Autozone has two listed as fitting but state they are street performance and 28 oz imbalance.

So looks like I am order my balancer from Rock Auto and just I guess have to take time off from work till it comes in and I get it fixed.

 

Dumb question, where do you buy a 50 oz balance balancer for a '82 302?

Ive checked autozone nothing, Oreilly nothing, Napa nothing, just checked rockauto and they have only race/performance balancers.

So I am at a loss right now.

 

I would not rule out the timing chain.
TDC the engine using Number 1 cylinder and check the balancer if it lines up you got a timing chain issue.

 

Well that is good for checking spark only not if all the holes have compression and why producing power.

As for the balancer slipping are you sure you had the #1 plug hooked to the light? IIRC it is not the same as the '69 El Camino motor is on the other side right?
It still could have slipped I just want to make sure you are checking it right.
Now I am also thinking if it moved a little it may move again. Mark the outside & inside with a line then run the motor moving the RPM up & down. Then check if the line still lines up.
Dave ----

 

I was on number 1. passenger side front most spark plug wire, the ford racing wire was also marked 1 as well. With the timing light I advanced it to 50 degrees advance and I never saw any marks all I saw was the thick side of the balancer telling me the balancer did slip.

As far as compression goes, the motor is running dead smooth ignition wise the tach is not bouncing around its vibrating a little due to the engine shaking the whole truck. Once I pulled the vacuum advance and the truck smoothed out some at 500 rpm the tach was showing the ignition was pretty smooth.

My problem is finding a balancer right now. Every thing I find like the Dorman 594-024 is listed as 50 oz imbalance, summit says '84 and up. but Dorman`s site says '81 and '84 and up. Skipping over '82 and '83. I look up for a '82 and places like Oreilly only brings up for a 200 6 cylinder. Then other places bring up a replacement balancer but states its a 28 oz imbalance but I know mine is a 50 oz imbalance cause it is the big balancer not the small one.

I keep looking at the Dorman 594-024 which I can get local but I am reluctant since Dorman says it doesn't fit an '82 and when people ask about '82 and '83 the reply from the online store says it doesn't fit. I thought the balancers when they made the switch to 50 oz were all the same.

As far as moving a little I think it moved a lot cause I advanced timing 50 degrees and it didn't show up any marks on the balancer. I think the balancer slipped to the point of being 180 degrees from where it should be.

 

Again verify that the chain did not jump. You disconnecting the Vac advance should not make ANY difference to how the engine runs if the balancer slipped. But it will make a difference if the T-chain jumped.
It takes 2 mins to pull number 1 spark plug and double check. Cause vibration like you are describing can happen with the T chain jumping. Plus it happened accelerating from a stop another indication it may be the T Chain. Balancers tend slip at shut off.

 

How do you do that if the balancer slipped?
I know you can feel for the piston at TDC and check it the balancer marks line up. That would confirm if it slipped or not and the better way now that I think of it.
Because the timing light does not light at the right "time" and because the balancer did line up from the above test, would that show the chain jumped?
Being the dist./spark is run off the cam and the cam from the crank by the chain I guess that would show right?

You are making me think to hard too early
Dave ----