My 79 Spider started stumbling on acceleration recently, and then she wouldn't start at all. Thankfully she was in the garage when she didn't start.
I checked for fuel flow and I saw that the carb was getting fuel, so I pulled a spark plug, and lo and behold, the 4 part prong (electrode?) at the top of the plug was almost completely gone, burned down to nubs. I pulled the other 3, and I found the same thing. These plugs were the gimmicky 4 prong Lodge Golden with only a few thousand miles on them. The car was running very good before this problem, and since I just replaced the plugs with Champions, she is running fine again, but there could still be a problem.
Cheap plugs? Is the spark to hot? Is it to lean or to rich? My guess is to lean, but there is no pinging, knocking or dieseling. Bad timing?
What say the experts?
Spark Plug Issue
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- Posts: 672
- Joined: Sun Nov 14, 2010 1:13 am
- Your car is a: 1982 131 Superbrava warmed 2.0 litre.
- Location: Tasmania, Australia
Re: Spark Plug Issue
What plugs are you running? Need more information than a brand name. I've only ever run NGK BP6ES in my Fiat motors. We did have a customer with a 1600 pushrod motor that was burning oil and fouling plugs, we tried BP5ES, a bit hotter, to try burning the oil off, but the centre electrode burnt away.
Mick.
'82 2litre 131, rally cams, IDFs & headers.
'82 2litre 131, rally cams, IDFs & headers.
Re: Spark Plug Issue
if the catalyst is plugged, you'll burn the tips right off the plugs
Re: Spark Plug Issue
The cat is long gone Mark.
I don't know the number of the old plugs, just that they were Golden Lodge, 4 prong style. I've heard some bad things about the 4 prong styles. Could they have been a problem? The Champion plugs I just installed are Copper Plus 415/RN9YC, single prong. That's what the part's book called for on a 79 Spider.
I don't know the number of the old plugs, just that they were Golden Lodge, 4 prong style. I've heard some bad things about the 4 prong styles. Could they have been a problem? The Champion plugs I just installed are Copper Plus 415/RN9YC, single prong. That's what the part's book called for on a 79 Spider.
- azruss
- Posts: 3659
- Joined: Sun May 30, 2010 12:24 pm
- Your car is a: 80 Fiat 2000 FI
Re: Spark Plug Issue
I have had good luck with dual pronged plug in an old motor with leaky valve seals. Helped fouling issues. I bought some Golden Lodge plugs but replaced them when i went with Mark's dizzyless ingnition that required a much large spark gap than i could achieve with the 4 prong plugs. With past Fiats, i found Champions to run the best.
Re: Spark Plug Issue
I like the way you think.majicwrench wrote:Don't overthink it, get rid of those oddball plugs.
I took her out for a nice ride today and she felt great. I'll pull a plug after a few hundred miles and see how they look.
- divace73
- Posts: 1380
- Joined: Sun Oct 17, 2010 5:59 am
- Your car is a: 1980 Fiat 124 Spider Silver
- Location: Sydney, Australia
Re: Spark Plug Issue
just to add my 2c worth to this, I bought the Bosch 4 prong plug about 10+ years ago and haven't had an issue with them...unless of course I change them out for something else to see if there is a difference????
Cheers David
-=1980 silver Fiat 124 Spider=-
If you want to see pics of my car (and other random stuff) >>click here<< OR
see my >>You tube channel<<
-=1980 silver Fiat 124 Spider=-
If you want to see pics of my car (and other random stuff) >>click here<< OR
see my >>You tube channel<<
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- Posts: 212
- Joined: Thu Nov 27, 2008 4:03 pm
- Your car is a: 1972 Fiat 124 spider
Re: Spark Plug Issue
The electronic ignition on a 79 puts out a way hotter spark than anything available when those plugs were designed.
- Kevin1
- Posts: 399
- Joined: Tue Feb 17, 2009 8:55 pm
- Your car is a: 1980 Spider 2000 FI
- Location: Maine, USA
Re: Spark Plug Issue
Every time I have ventured into the "better" spark plug experiment for the Fiat I have always come back to Bosch or Autolite, single electrode, boring old vanilla plugs. They seem to work best, at least in my car.
Re: Spark Plug Issue
You might want to check them.divace73 wrote:just to add my 2c worth to this, I bought the Bosch 4 prong plug about 10+ years ago and haven't had an issue with them...unless of course I change them out for something else to see if there is a difference????
My car ran fine until my last ride, when she started hesitating close to home. So I parked it and then it wouldn't start. The end for these plugs came quickly. How the car was running at all was amazing.
I will say though, that the car seemed to be a hair more responsive and even a bit louder through the exhaust with the old plugs. Somehow, the car seems tamer with the Champions. Perception, or real?
Re: Spark Plug Issue
Hmmm, I had no idea.DanD wrote:The electronic ignition on a 79 puts out a way hotter spark than anything available when those plugs were designed.
That would explain why they were so burned-up then.
So are the Champion's that the parts book called for good for this car, or will I wind up with the same problem
Re: Spark Plug Issue
Like Honest Abe said, don't believe everything you read on the internet. Or on this forum
The electronic ignition on a 79 does not put out much more than the points system.
And regardless of system, it will only produce enough voltage to jump the gap. If you gap plugs at .020, even the most high zoot system will only produce enough voltage to jump gap.
Which is why, on a high zoot system, you can run a larger gap, because it will produce the 50k volts needed to jump big gap.
Newsflash, high zoot systems don't cause plugs to fail.
Quit overthinking this and run stock plugs.
I like NGK, but Autolite, Champion, Bosch, they all work.
The electronic ignition on a 79 does not put out much more than the points system.
And regardless of system, it will only produce enough voltage to jump the gap. If you gap plugs at .020, even the most high zoot system will only produce enough voltage to jump gap.
Which is why, on a high zoot system, you can run a larger gap, because it will produce the 50k volts needed to jump big gap.
Newsflash, high zoot systems don't cause plugs to fail.
Quit overthinking this and run stock plugs.
I like NGK, but Autolite, Champion, Bosch, they all work.