200 I6 is goin through plugs like crazy

R

random hero

Active member
ok so i got my car on the road a week ago, and we adjusted the carb, and timed it(by ear...gonna use a light soon) and i changed all the fluids. now less than a hundred miles after the plugs were done, there pretty much shot, they spit and sputter at high rpms, and has a hard time warming up. it's been burning a lot of oil, any ideas what could be going on here? the plugs aren't completely black, there black and brown with a lot of carbon build up...would a lead addative help this?
 
Lead was used as an octane booster and turned out to have the side benifit of being a lubricant that mainly helped the valve seats in the head last longer. Shot valve seats will not cause an oil consumption problem. If your seats are worn adding lead now wouldnt help. Many of these/our earlier engines have had valve work done at least one time by now and if it was done any time after the mid 70's would most likely have hardend seats so the lead is not an issue anymore as far as lubrication. Oil consumption is usually a combination of worn rings and cylinder walls. Sometimes could be valve guides leaking oil into the chambers but that doesnt tend to be enough of a voulume that you notice it, it can mess with the plugs and smoke but without more info I would think its more likely just general wear on the walls and rings.

At idle remove the breather cap and try to feel if there is air being sucked in there or if you are getting air and fumes out of there (assuming you have a new enough setup to have a PCV system) If you feel a draw thats a good sign and how things are supposed to work, if you feel stuff coming out there that means there is a lot of 'blow by' which is an indicator of worn rings and such.

Whats your ignition system? What carb? Stock engine? What type/ how often do you drive it? What type of climate do you live in? What plugs and gap are you using? How long have you had this motor? Do you know the history of your motor?
 
stock points ignition system, carter yf carb 1bbl, yea, stock engine(72 maverick) mostly around town, i just ogt it on the road a week ago, i live in lower new york, but it's been off and on lately(60 degrees 3 days ago, 18 inches of snow on the ground now), i'm using bosch yittrium with a .035 gap, i've only had the car for a month or 2. i dont know the history of this specific motor, now where am i checking for air (on the pcv valve, or the valve cover) because the pcv valve pulls in a lot of air, but the valve cover does neither
 
On the valve cover is where you check but its hard to tell since you have the fan blowing. On a 72 is there a breather tube that goes from the valve cover to the air cleaner or is it just a combo filter/ filler cap like on the earlier engines?

If the thing has not been run for a long time or has done a lot of short trips its possible that things just need to get un stuck and reseated. I picked up a car in the fall that had been sitting for 10 years and before that looked like it had been used for a lot of short trips. It used oil and ran rough for the first few hundred miles. I changed the oil 4 times in that 1000 miles and added a 1/2 quart of ATF (or seafoam) the morning of the changes to help clean stuff out a bit. The first 3 times the oil came out nasty thin and black, the last time it looked like normal dirty oil for a 100K mile motor.

Drive it a bit more after you check the timing and such keeping an eye on the plugs and oil, if it keeps trashing the plugs maybe try a more agressive oil flush product but if that dont help you may have to do some internal motor work. A few hundred miles of steady crusin and some frequent oil changes will knock things loosen and reseat things if they are going to loosen and seat. The reason for frequent changes is to get fresh additives and detergents in there to do their thing, in this aspect the oil is kinda like a handy wipe that gets full of crap and no longer cleans it just moves the crap around. If you have done all you can do and its still a problem and you cant afford the time or money to pull the motor and have it freshend or rebuilt you could try a 'hotter' spark plug. A hotter plug is what it sounds like and runs hotter therefore tends to burn the crap(oil) off better than the standard plug. THere are other downsides and dangers if you get too hot of a plug so dont go more than one or maybe 2 ranges hotter than stock and remember this is just sort of a patch that is only going to help a bit to make the plugs last longer and is not going to help the oil problem.
 
my 200I6 used to foul the 5 and 6 plugs quickly, it was running rich, I went thru 2 sets of champions in a week, I got a set of Autolite 46's and ran them, still fouled ( took longer tho ) but I just rotated the plugs around when those cylinders fouled the plugs and started missing. always worked, never did get the carb tuned, decided I needed a turbo and a engine rebuild more.
 
i had the same problem with my 200.No 5+6 plugs would foul in a matter of days.A change to positive type valve seals changed that.I used the simple on
motor,compressed air method.3000mls on the same plugs since then...
OldSchoolOlli
 
When valve guide seals leak that bad your valves could look like this:
valve1.jpg
 
fordconvert":2xi3574z said:
When valve guide seals leak that bad your valves could look like this:
valve1.jpg
Click to expand...

none of mine were that bad, I did have a valve seal problem ( cracked/ non existant, most of them were fragments in the oil pan ). the 1st '78 head I got had that kind of crud on the intakes
 
If you don't fix the cause of the soot deposits from carb tuning or blowby etc, an MSD box will help treat the symptons. My engine has never had a bottom end rebuild and I suspect some blow by from some cylinders. (I also have another car with a carb that runs rich). Both cars fouled out plugs very quickly. Anyway, an MSD box on both vehicles has eliminated the plug fouling problems. It also picked up in performance and idle quality, no doubt from not having fouled plugs. You can use your stock points setup to trigger the MSD box if you like.
Doug
 
You must log in or register to reply here.
Back
Top