I just changed my plugs approx 1000 miles ago and having some missing going on. My car burns oil and blows out a thick cloud at start up if it has been sitting for a while. I think one of my plugs are fouled up. Hopefully will be able to have this fixed over the winter.

Is there an easy way to find out which plug is fouled besides pulling them out and looking at them? Could I just pull the wire off the distributor cap one at a time ultil it hit the one that does not effect the idle speed when it is disconnected?

Sounds like you have some bad valve seals. I would check those before the plugs. I'm sure someone else will validate this info soon :)

Yeah, I got some engine issues that need to be fixed. I spoke to an engine guy by me and he did bring up the valve seals. I am looking to keep the car running as best I can for now until I get some cash to fix the problem the right way.

Just pull the plugs and replace any fouled ones with a hotter heat range plug....that might hold you till you get the seals fixed.

I've always used an ice pick, a pointed screwdriver thing. Hold it against the exhaust manifold/header and punch a hole through the plug wire end where the plug tip is. Might not sound like a good idea but I've done it for years with no problems. Grounding the plug will kill that cylinder and slow down the engine if it was firing ok, no difference if it's fouled. I've heard that pulling the wire is not good on electronic ignitions.

if you have headers its very easy just start it up and squirt water on the header tubes the cyclinder thats fouled will not get hot and the header tube will remain wet

Little Naples
The plugs in now are AC Delco R45TS or R46 (I have to look), which has a shorter electrode. The shorter the electrode, the higher the heat range, correct? I matched the pluges that were in the car when I did the tune up.

Strange thing is, when I went to Pep Boys to get the new plugs, the guy gave me Champion plugs with a longer electrode than what was in the car. He did say the plugs he gave me is what was called out for with the 5.7L 350 engine. I did not take those and found new plugs to match the one I pulled out.

Tom3
I understand the process but knowing my luck I will screw up the plug and wire at the same time. I wasn't sure about pulling the wires off and if it would have any complications in doing that. I will not pull the wires and check that way.

Mwilson
I do not have headers (yet), just the stock manifold. That is definetly a good tip to remember.

I guess I will be pulling the plugs to get a visual on their condition.

Could it be that the plugs I originally pulled out were not right to begin with? I have a repair manual that does list part numbers for the proper plugs. I will have to check it out tonight.

If you're putting in plugs that are too cold they will foul up.

If this is a stockish motor Id put some R46's in and if the blowby is real bad a temporary fix would be some "Non fouler" extensions.

Just pull the plugs and replace any fouled ones with a hotter heat range plug....that might hold you till you get the seals fixed.


that's good advice...;)

Anytime I feel I've got a cylinder that's not performing I use an Infra-red thermometer and aim the laser at each cylinder. The plug that's not firing correctly will be cooler than the other cylinders.

I don't recall the brand I have but here's an example from summit:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2DG1054&N=700+%2D213326+115&autoview=sku

It's a quick, clean, non-invasive way to narrow down the search.

I also use it to diagnose cooling problems in the car.

Chris, that is an interesting instrument. I just looked at the Summit link. How does the headers or exhaust read off that? That would take the guesswork out of diagnosing a cooling problem for sure.

From M,

"a temporary fix would be some "Non fouler" extensions."

Those suckers are REALLY temperary!(Sp?)!!

Just ask me how I know!! I think I bought a handfull as well as pulled a set off a junk engine back then ........

Buy "resistor" Autolites w/ LONGER extended tips and at least two heat ranges hotter and go!!

Been there, had to!!

pdq67

I decided to buy new plugs and replace all of them with the same ones, AC R45TS. I thought I put in R46. After pulling them, I noticed a white powdery looking deposit on the electrode, passenger side only, driver's side seemed OK. None of them appeared to be oil fouled.

My fuel/air mixture needle on the carb was set around 10 o'clock, toward the richer side. After replacing the plugs, I leaned out the mixture to about 12 o'clock (I guess 50/50). Was also listening to the engine idle and this is where it seemed to run the best.

Went out for a spin afterwards, and all I have to say is HOLY S*&T.

I stopped at a light and the engine idle is smoother. I don't feel like I am fighting the engine when braking. AND, the acceleration is noticeably quicker. :D Feels like a new engine, ever better than when I did the original tune up.

This is still a learning experience for me, but I am a little excited that it is running a lot better. Lets just see how long this will last, hopefully until I can get the engine work done.

P.S.
What are non fouler extensions?

if you have headers its very easy just start it up and squirt water on the header tubes the cyclinder thats fouled will not get hot and the header tube will remain wet

Thats what I've always done. You can easily tell wich ones are'nt firing hot enough or at all.

My fuel/air mixture needle on the carb was set around 10 o'clock, toward the richer side. After replacing the plugs, I leaned out the mixture to about 12 o'clock (I guess 50/50). Was also listening to the engine idle and this is where it seemed to run the best.

well, if you're guessing you're a/f ratio based on clock position, you're not being very accurate. what carb you running? i'd suggest getting the timing dialed in and the carb dialed in using a vacuum gauge...

did those plugs look lke this:
http://www.gnttype.org/techarea/images/plugs/champ9.jpg
on the way to ash fouling? symptom of oil burning... the problem will probably come back till you fix the underlying blowby or valve seal issue...