New spark plugs: loss of power.. huh?? :?

i replaced the autolite A7's with the same plugs (bought on ebay... oem condition new A7's).

The plugs i put in are brand new... the only ones were covered in all kinds of carbon, and now the jeep is running worse! give her some gas and she sputters and backfires.

I'm thinking shes getting too much fuel? (or not enough?) I'm going to go try to find my FSM now to figure out where the adjustment screw is on the carb. any advice? the gaps on the new plugs are ok

 

Damn... just had the engine running to adjust idle mixture.. while i was in the garage grabbing a screwdriver, the engine just quits... no hesitation, no sputter. just quit.
this happened yesterday, and the jeep has had a battery draining problem lately...
now i dont know what to do :?

i just tried starting it back up and it wont fire... sounds like it wants to, but it wont. plenty of gas getting to the carb though. what could that be? coil? rotor? would any of that cause the stalling and the drainage problem combined?

 

The first thing I would do is try wire brushing off your old plugs and put them back in. See if you run better than w/ the new ones. You could actually have some bad plugs, it has happend to me before.

 

ok i figured out the stalling problem.. my fuel gauge just quit working and i was out of gas. put some more gas in the tank and she fired up fine... still backfiring like crazy though and running like crap. oh... the backfire is from the carb by the way.

Glenn it was running great before... a little rich, but no hesitation. Great throttle response.

I guess i'll pick up some champion plugs tomorrow and see what happens. just seems weird... i replaced the plugs with what was already in it, just newer, and it runs bad...

 

You might try some NGK's. I've had a few brand new-bad plugs from autolight and (I think) champion (on other rigs) and have yet to hear a bad thing on the NGK's. They're so cheap (~1.50 each) you can't hardly go wrong.

I had them cross reference the champion J8's at the parts store... and they gave me p/n BR6S. I have no idea if that's the ideal/right plug or not, but I've got 'em and my engine runs pretty good. (btw, If you do a cross reference on NGK's website, you may get a different part number.. depending on how you enter it in, I've gotten B5HS and BR5HS, B6HS and BR6S).

I'm still not entirely sure what a resistor plug is, or whether or not I should be running one. (I think the BR6S is a resistor plug). Any thoughts on that?

 

A resistor plug will help suppress that annoying radio noise you get through your radio.

 

plugs are very easy to damage. Be very carefull not to drop them. Bad plugs from new are very common. As for brand, its the old opinions are like A-holes expression. Iv heard many different things from many different people. its all personal preference

 

Why did you change them in the first place?

 

they looked pretty cruddy... TONS of carbon deposit, and i've been trying to figure out the battery draining problem. just going over one thing at a time.

 

Get some new ones from the FLAPS, regardless of brand. Four spark plugs are cheap, and IMHO buy them at your local store. There's no reason to buy 4 spark plugs on Ebay, fer cryin' out loud! You have no idea how they were handled and stored, and like was mentioned...dropping one on a concrete floor can kill it right there.

Plugs are sensitive creatures and need to be handled gently, but they're cheap enough to replace without question if they give you any crap at all. I don't want to tell you about all the parts I replaced on my old pickup, because "the plugs aren't that old, can't be them". Grrrrr.

 

yup.. heading out in a few minutes to pick them up. the only reason i bought them on ebay was because some guy had some unused original A7's and i thought it would be cool to have something period correct (when i bought them). Now i dont care, i just want her to run good

 

Check firing order. I had my rotation wrong (clockwise) It should have been counterclockwise on my 3B.
It actually ran and I was able to drive it barely, but backfired and was real rough.

 

I second that. Check your wires, could you have possibly mixed them up? With a couple wires swapped they will usually start, they just run like the way you are describing.

 

you guys are the best
I had tried the new plugs... same problem, put the old plugs back in... same problem. I came back in to update this post and saw what you wrote about the wires being crossed... went back out and crossed over the two middle wires (two most likely to get crossed i figured)... fired her up and shes purring like a kitten again

i guess sometimes, the biggest mechanical problem is the nut behind the steering wheel.

Thanks guys. beers are on me if you are ever up in my neck of the woods

 

Woo-hoo!!!

 

Good deal. I've done that before too! Worse yet, one time I was trying to get the dwell/points set just right. Eventually I adjusted them to the point where it would no longer run. So I set the points back (where it did run) and it still wouldn't start. We tried darn near everything to get it to start before I finally noticed that the rotor was still sitting on my fender. R)

 

OMG! Go sit in the corner for that!

 

too funny... i guess the answer is sometime so easy that we dont even think of it. Now if i could only figure out why my battery keeps draining...

 

That's a whole 'nother issue, but the spark plugs won't do it.