The Dodge Challenger Message Board

I've just finished putting 500 miles/800 Klm on my modified 440 and am in the process of doing the 1st oil change and changing the plugs. (I say in the process because with my wife working full time and a 16 month old son time management has a whole new meaning to me!)

A couple of the plugs are light brown on one side and dark brown/black on the other, the other plugs are the normal light brown except #3 and #8, they are wet.

The colour of #3 and #8 are dark brown/black, they are wet not sooty. The light viscosity makes me suspect it is fuel.

I took the plugs to the local speed shop that supplied most of my performance parts and he agrees that there is definitely a problem with #3 and #8.

He has worked on my car and we had some problems with the ignition system that we thought we had sorted out. It is currently the Mopar Orange Box with Balis (spelling?) Resistor and a Mopar coil.

When the engine is running there is no noticeable smoke but there is some black around the tail pipes.

I have not had time to do a compression check yet (that time management thing)

We SUSPECT that there is still a problem in the ignition system and I am debating scrapping the existing system and replacing it with a MSD 6AL (more spark and a rev limiter to boot)

Before I go throwing more time and money at this the Speed Shop owner suggested we do some more research, he is contacting the Chrysler Dealer he deals with and MSD. I am contacting you guys/gals to see if you have any thoughts or solutions.

Thanks in advance:
Ron

Tricky.

You don't say how modified your 440 is but I think the standard Chrysler ignition is fine for most street/strip cars unless it is over 450 hp. Then I would go for a better system for sure. A better system is optional below that level in my opinion unless you are looking for a small increase in fuel economy.

I really don't understand how you can have problems with this system (and you don't say what they were) unless it was installed badly. Electricity just needs good contacts and it will flow through metal wires into your spark plugs. A more expensive system is not the cure for a badly installed system. Make sure things like the orange box and the engine all have a GOOD earth. The orange box is just a switch. There is nothing complicated in it that might fire only 6 cylinders and not the same two. How clean are the spark plug wires to these two plugs? How well connected are they at both ends?

It sounds like you are running rich. At least on some cylinders. The plugs should be all be a light or medium tan. Make sure you do not have fuel leaking into the engine from somewhere on the carb. I am not sure about the 440 but I think it may be possible for fuel to drip onto the plugs if there is a leak. Worth considering anyway as that may be the problem.

I think you are more likely to find you have bad connections in the ignition system or earths myself.

If it was my car I would make sure of every electrical connection in the ignition system. Clean every wire and joint. Solder joins in wires where possible. Fit a new cap and rotor if it has seen more than 6000 miles.

I have written a few fault finding hints in the electrical section of this message board. Work your way through them.

Then make sure the carb does not leak and fit a rich/lean indicator to tune it. Again I have written stuff on how to go about that.

THEN see how your plugs are doing.

Hope this is of some help. It might give you some ideas to work on anyway. Good luck.

Just an update.
Dave thanks for the advive, the owner of the Speed Shop and I spent a fair bit of time going over things, a grounding strap had been added earlier so it was trial and error. Finally (although they were suposed to be new) I suggested we check the distributer cap and rotor. The owner said hey why not we have checked everything else. The cap had green corrosion on the contacts! This seemed strange as it was supposed to be new, the owner did not supply that part and suggested that it was either not new or maybe had beed sitting on the shelf for a long time.

I ordered a new cap and rotor (Accell) and after instalation the, Stumble/Miss that had been occuring at around 2100 RPM was gone.

I haven't had time to drive it much between work, wife and 19 month old son but the exhaust is still irritating to the eyes and has an odor. Would this be caused by unburned fuel?

Since the engine still has only about 550Miles/900KM on it perhaps I should just leave it alone for now and give it more break in time. After all it is just about time to put her in storage for winter.

Thanks again for the good advice, it pointed us in the right direction.

Is it the exhaust at idle or at speed that causes the bad smell?

The strong order is most likely due to the car running VERY rich. This can thin the oil.

The break-in period is very important. If your oil gets very much petrol (gas) in it you can cause a lot of premature wear and in extreme cases even damage to the bearings.

It may be a leak in the carb causing it if normal idle mixture tuning does not put it right. You need to fix this soon. The best way to get a carb right is to fit a rich/lean indicator.

Oil or crankcase fumes can also cause a bad odour and make your eyes water but as your engine is almost new this should not be the cause.