If you have verified that the plug wires are routed correctly, then I would tell you to go back to stock plugs. Since you changed the plugs, which developed these symptoms, then that's the root cause.

 

+1 if you can't figure it out.

 

The problem is fixed. CHanged the plugs with some champion plugs I bought, and it runs fine. So a fiar warning, STAY AWAY FROM AUTOLIGHT!!!!!!!!!111

 

I would not say stay away from autolites because thats what I run with no problems, I would say stay away from their platinum plugs.

It seems some people have a problem running the more expesive platinum plugs thats why I buy the cheap copper ones that work great

 

gotta be champions...

 

so - do you think he had a bad plug, or a bad gap, or a loose plug, or loose wire in the autolite install; or do you think there is actually something inherently wrong with the autolites and that the champion plug is actually different ? my .02 is that all plugs are all pretty much the same and he picked up a mysterious defect in the original plug swap. this is a good reason for only changing one thing at a time - in the event of a problem, you know what to address.

 

Not necessarily Autolites in general, but I have seen repeated complaints on here about Platinum plugs in general.

Iridiums seem to be fine, but they are even more expensive. Last a lot longer though. My previous set were stock-type copper NGK V-powers, and now I am running 3923s. I noticed that occasionally, especially when cold, the truck has more hesitation when i step on it with the 3923s. Also seems to have lost a little bit of "snap" during acceleration. Champions are up next.

 

Yeah I use Autolite 3923's also. I have had them in for about a year now with no issues. Its really hit and miss when it comes to spark plugs.

 

Good job, and might I add that I hate it when I'm right.

I question the both of you, because I stated earlier I tried the Autolites and they made my truck run poor, mileage dropped, and I had a misfire on #5. The plugs are still in my garage, and as far as I remember, they're not the platinum plugs.

About 13 years ago, I had a 1993 Ford Escort wagon with the 1.9L that I swapped to platinum plugs. It ran great and could even get 400 miles to a tank of gas with the A/C running.

 

If I were to guess, which I am, I'd say that he's got either a marginal plug wire or a minor case of operator error (wire not quite properly seated) or both. If the plug manufacturer says that this plug fits this engine, then unless you're pushing the engine into extremes of RPM or heat it's pretty sure to work well enough to avoid problems. The engines we're talking about here have been around for 40 years or more and the big changes have come in the control systems rather than the combustion chambers -- the same darn plugs that worked in 1970 will work just fine in 2010 and the folks who make them have had at least that long to figure things out.



I'd put a six-pack on the bench and say that if he swaps out rotor, cap, and wires on the working plugs without problems, throwing those Autolites (if they're not actually in some way broken) back in won't introduce any new problems. I could be wrong, but I'll bet the price of a locally available sixer on it.