No more Autolite plugs
 

I have had a strange stumble on my '87 for some time, and have been chasing it until this weekend. It would only occur at idle, after fully at temperature. No stumble when holding the brakes and pressing throttle.
I had installed Autolite platinums about 5k ago, and they looked good, so I continued to t/s. built a new set of wires, fully rebuilt the throttle body, and it still stumbled.
Finally, this weekend, I installed a new set of NGK platinums this weekend.
FIXED!

Re: No more Autolite plugs
 

I always use regular NGK Copper plugs in my C5.

Re: No more Autolite plugs
 

I only run delco in my gms motorcraft in the ford and champion in Chrysler

Re: No more Autolite plugs
 

Bought a set of delco R43's for a rebuild. Fought a stumble for hours.
Backed it out of the shop at midnite and noticed a ton of spark escaping from the #1 plug. Replaced it. Fixed all my issues.
Always figured the box had been dropped and cracked the porcelain

Re: No more Autolite plugs
 

Tried a set of Champion plugs on my 83 and it never ran right, went back to AC Delcos and she's been running great ever since, Champions never again ;)

Re: No more Autolite plugs
 

I've tried Autolites in both Fords and Chevys with poor performance in both. AC Delco and NGK have been the most consistant for me.

Re: No more Autolite plugs
 

I run copper core plugs. You know the sparky kind. Either one seems to light my fire all the same. Except those e3 ****s. Those are designed to work on a hemi center plug chamber.

Re: No more Autolite plugs
 

Yeah for ignition problems that watching an engine run in the dark is the oldest good trouble-shooting tip in the book. And it stills works today.

For my trucks that have conventional ignition early HEI, or points I run the cheapest plugs I can buy at the time. And always go a range hotter on the ones that are turning themselves into a 2-cycle.

Re: No more Autolite plugs
 

Can you explain? Is this to check for sparking out? (like when a wire is on the manifold) Not trying to sound dumb, its just something I haven't heard of yet

Re: No more Autolite plugs
 

Just look for abnormal spark around the wires, plugs etc
Do it in pitch black if you can. Mine was an accident that I spotted it.

Re: No more Autolite plugs
 

Its to check for any kind of things that will cause a miss. You'll look for spark jumping from one plug wire to the other. Wires too close in parallel will do this. Sometimes you can spot a plug boot with a crack and spark will jump to the head, or exhaust manifold.

Also in addition to letting the engine idle and looking for problems a quick rev or two might reveal spark jumping.

Re: No more Autolite plugs
 

some may not like this but, with later crate motors in my trucks I have used BOSCH Platinum with real good results.

Re: No more Autolite plugs
 

I've always had problems with autolites. Delcos run just fine for my '96 and '79.

Re: No more Autolite plugs
 

Cool thanks, good tip