200 running rough

[Anonymous]

my 200 in my 67' stang is running rough.So far I am not driving the car but I am trying to get it ready so when the rust repair is done I can pull out of the garage and not look back..

So, the previous owner was a moron and could have done almost anything to this car. The condensor was missing in the distributor for some reason which took me a day of starting fluid, new plugs, new cap and rotor- before I noticed it was not there.

Also, the air filter was off of a 2bbl carb and was way bigger than the 1bbl opening, allowing it to suck up dirt- it was chrome and looked neat though. I do not believe it was driven like this though.

The carb (and the rubber hoses) were all spray painted chrome. (probably wont affect anything, but what an idiot)


Now that you have the story, I have it running but it bucks and sputters at idle and wants to die if I rev it up too much. I adjusted the timing and for some reason it wants to run well at about 20 degrees. I beleive it is supposed to be like 12-(some idiot spray painted over the engine decal that would've told me)

Once the engine warms up it starts to sputter again and no amount of timing movement will stop it. This leads me to believe thatthe carb is out of adjustment too. All I have touched on the carb is the idle screw so far.

Anyone have a suggestion what I should do next? I dont want to get too many variables going at once.

 

[ludwig]

You might think about rebuilding the carb. It is not very hard and probably will make a difference, even if it doesn't solve the whole problem. You might also just get a modern carb, but this takes more money. Rebuild first.

Barring that, clean it all up with carb cleaner inside and out and blow off with compressed air. Make sure all the slides and levers and such are working right. Make sure the choke butterfly is pulling off completely. If not, either block it open or get it working properly. If it is half closed, you get a stumble when you accelerate and it will idle too fast.

Check your PCV valve if you have one. Replace if all plugged with black soot.

You could have a vaccuum leak around the base of the carb that gets worse as the engine warms. Spray WD40 or squirt some motor oil around there and see if it evens out when the hole is plugged. If this causes a change, the rebuild kit will have the gasket set. Use GaskaCinch or FormAGaset when you put it back together on the manifold seat.
Make sure the throttle plate is working properly too. Again, clean and fiddle until it is running smooth.

Depending on how long it sat, there might be some contamination from the fuel tank that blocks the fuel flow. Pull the fuel line and let the gas flow into a clear glass jar to see if there is crud coming through. If so, replace the filter at the carburetor and put in an in-line fuel filter with a clear vial. On the other hand, if it will idle okay, then starts to stumble as the revs go up you could have a situation where crud is collecting on the screen in the tank and blocking the flow. You'll have to drop the tank if this is the case and clean it out or get a new tank. Cleaning is the first choice.

The ring on the harmonic dampener might have slid on the rubber membrane over the years, so that is no big deal. Just find TDC in the 1st cylinder and put a new mark on the ring.

It could be the fuel mix, although I doubt it. Find the fuel mix screw, turn it in until the motor starts to stumble, then back it out about a quarter turn.

If you want to go modern, replace the stock ignition with a Pertronix ignition. It really changes the starting and the idle quality. It is a major improvement. But I would wait on this until you get the stock configuration tuned up.

There are several things that could be going on inside the carb, like accellerator pump, lack of ball check valve, plugged idle circuit. These will be addressed with a rebuild or cleaning. Personally, I would get a second carb at the junkyard. Fool with it until you understand what moves what and where. Then rebuild this salvaged one, put it on and see if anything changes. I bet something will if you got all the passages and such cleaned out.

 

[Anonymous]

Eventually my plan was to get a distributor from a late 70/early 80s fairmont and use the ford electronic ignition. As far as I've seen, they should interchange without any issues.

As for the carb, I rebuilt carbs before and I dont like it. I do however have a 2v carb off of a mid 80's F250 351W that I would like to use on the 200. If I am going to have to rebuild a carb and re-adjust it, shouldn't I just swap everything now?

I was going to get everything stock working just to try it, and then swap it out later.


I dont have any vacuum leaks and since everything in the ignition is new, I can guess its the carb. I already tried the Seafoam.

 

[fordconvert]

I wouldnt mess with a 2bbl untill you are sure you have a solid good running motor and fairly well dialed in and working ignition. The 2bbls are not just a bolt on and go, they require a fair amount of tweaking and some mods to linkages and air cleaners and such.

What carbs have you rebuilt before? If you have done a Quadrajet I can see why you dont want to mess with another one. The 1bbls (especially the 1100) are easy. With all the problems the po created I would open the carb just to see whats in there and what may be missing. If you dont want to mess with it take it to The Carb shop in Maplewood (just south of 36 on white bear ave) they do great work including throttle shaft bushings. I have had them do several carbs for me and they have always just bolted on and worked with no adjustments. IIRC they told be the 1100 would cost $125 with bushings, kind of a lot for a 1bbl but I at least you will know its as good as it can ever get.

Have you done a compression test and leakdown test? Rock the crank back and fourth with wrench looking at the rotor on the dizzy, this will give you an idea how much slop there is in the timing chain. How were the bearings in the dizzy? With points wear causes the dwell to wander all over the place and can easily cause a miss or roughness. Did you set the dwell with a gauge(gap) or use a meter? A meter is the best way to do it because it shows exactally what the dwell is, the gap method only gets you close and if you set it on a bad lobe or not centered on the high spot it will be wrong. If it has been sitting getting it out for a drive will most likely help it, you need to get it good and hot and run some fresh fuel and oil through it with all the detergents. If you dont want to or cant drive it you can run it without the valve cover on. Some oil may splash out but for the most part it stays in. You can then observe the valve action and use a straight edge to compare how far the valves open. A cam/valve train problem that almost makes the motor die should be obvious just by eye.

 

[ludwig]

Of course you could just have a blown head gasket. That will degrade performance real fast. Happened to me right after the rebuild.

 

[Anonymous]

I rebuilt the carb on my 75 pickup 300 (1 bbl) wasn't too bad but I also own older snowmobiles, so I have to rebuild a carb everytime I stop to use the bathroom. Both are simple but I still get sick of it.

I am not familiar with the point distributors. My truck was the first year they switched to electronic ign. I thought the dwell was set correct but it is probably wrong. I don't have the correct meters and such and I
re-adjusted it a few times by eyeing it up and retightening it. I didn't notice much change and therefor assumed it wasn't a major contributor to my sputtering.

I do not think my head gasket is bad, I changed the water pump and didn't notice any oil. Also the oil doesn't smell. I would assume that if the gasket was bad enogh to cause it to run that rough, I'd see oil/antifreeze mixing.

 

[pedal2themetal45]

points are an important thing >.............. you need to get the right tool... changing the point gap (or dwell) WELL change the timming and it needs to be percise.. with in a few deg's.
tim