Spark Plugs Keep Going Bad - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
 
LinkBack Thread Tools Display Modes
post #1 of 4 (permalink) Old 02-18-10, 08:30 PM Thread Starter
Registered User
 
Join Date: May 2009
Posts: 33
Spark Plugs Keep Going Bad

Hello Again,

I have 302 V8 from a 1985 Lincoln Continental that I have dropped into a 1949 Ford F1 that I am restoring. The engine was rebuilt at a local machine shop. Here are the engine specifics:

Cylinders bored 0.040 over
New stock pistons
Stock heads with 120lb valve springs
CompCams Thumpr Roller Cam with 0.531 lift intake, 0.515 lift exhaust
Funnelweb 7-1/2" rise intake
600cfm Holley carburetor
HEI 50K Coil Disributor

I originally began with stock Autolite plugs. I start the truck occasionally to move out of the shop or a quick trip around the block. I haven't put it on the street yet. It began popping and backfiring on one cylinder and spread to 2-3 more cylinders. I tested everything I knew to test and finally bought a new set of Iridium plugs which cured the problem. However, a couple months later the problem started again. It got so bad the truck won't start now. I pulled the plugs and cleaned them but that didn't help. I pulled the coil, ignition module & pickup coil from the distributor and had them tested at the auto parts store. All checked out OK. I have since put new Accel wires on, tried a new coil in my distributor and finally bought a new distributor which is installed now. If I test a plug straight from the distributor I am not getting a spark. The plugs are gapped at 0.045. I tried one of my old Autolite plugs and I am getting a weak spark. I know if I buy a new set of plugs my problem will be cured once again for a short while. Since I have had 3 different new coils installed, I know it's not the coil, besides I have a new distributor in now. What is causing my plugs to go bad?

Thanks for your help......

patioman is offline  
Sponsored Links
Advertisement
 
post #2 of 4 (permalink) Old 02-19-10, 06:53 AM Thread Starter
Registered User
 
Join Date: May 2009
Posts: 33
Re: Spark Plugs Keep Going Bad

I'm going to assume that the coil in my first distributor was bad causing my Autolite plugs to go bad. When I replaced them with the NGK Iridiums, it ran OK until the bad coil eventually ruined them. No matter how many new coils I put in, even a new distributor, it will not be OK until I get a new set of plugs in. I will do that this weekend and hope and pray my reasoning is correct.
patioman is offline  
post #3 of 4 (permalink) Old 02-19-10, 07:43 AM
2002 F150 XLT
 
Bert's Avatar
 
Join Date: Nov 2008
Location: Oregon
Posts: 10,312
Re: Spark Plugs Keep Going Bad

We haven't had that problem. I hope you're right too. Good luck and let us know the outcome.

Bert
Bert is offline  
post #4 of 4 (permalink) Old 02-20-10, 04:46 AM Thread Starter
Registered User
 
Join Date: May 2009
Posts: 33
Re: Spark Plugs Keep Going Bad

Well I put new plugs in last night. Went back to stock Autolite plugs. She fired right up. Does however sound stronger and the idle was actually higher than before telling me it is getting a lot more spark than before. I am going to replace my power valve today. I am swapping out the number 65 for a number 45 because of the low vacuum as a result of my high lift cam. I am currently running real rich so I will lean out the carburetor today as well. I think my old plugs fouled to the point of no return. At least by cleaning with a simple wire brush. I will put them in a spark plug cleaner and try them again later. I guess I will wait and see if the new plugs last longer.
patioman is offline  
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > The Garage - Tech Forums > Engine Specific Tech > Cleveland Tech


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome