Hi all, I am just trying to tune my car (75 GT4) - coming up against a bunch of challenges and uncovering all sorts of "fun stuff".... I just got through adjusting floats, cleaning the carbs and jets / emulsion tubes, replaced the carb top gaskets. I found a couple possible oil leak sources that I think I have identified and/or addressed. I pulled a couple plugs tonight as tomorrow I want to do the actual tune. I am very upset with what I found. Pictures below. They are all very wet fowled (the term I found as I viewed images of plugs on Google). I pulled the whole rear bank and two from the front - all are the same. I hope this is from the carbs being set way too rich. The whole purpose of my going through this exercise is that I am experiencing a misfire that starts if I am putting my foot in it during the mid-range. Questions 1. Could this come from a "very rich" scenario over time? 2. Is this from an oil leak (around the piston, gasket or valve seats) 3. I tried to clean the plugs (pic 1 vs. pic2) and they didn't really clean perfectly. Is it necessary to replace the plugs? 4 Based on the answer to question 3 should I continue to tune the carbs? In my research there is a leak down test to help figure out the problem. Where should I start? 5 I have white smoke coming out on cold start up. This points to head gasket. It seems to go away after driving but I'm not sure. I'm thinking I should replace the plugs and tune properly. Then see if the fowling continues. See if the white smoke continues. Leak down test, etc. I can't really pull the motor right now - probably moving around the end of the year and I have a very small garage. Besides if I'm pulling the whole thing apart, it will likely be at least a year (if I'm lucky) before getting it all out together. Can you guys help me answer the questions above and my thinking is on the right track. Any suggestions? Thank you in advance! Spencer Edit: And I just realized that I spelled fouled with a W. I can assure you that I have no dirty chickens in my engine bay. Damn you second glass of scotch! Image Unavailable, Please Login Image Unavailable, Please Login
You could run a compression check (or leak down test if available) to get a better idea of your engine's health. If that checks out, it is probably something simple involving tuneup or technique. Also, try the NGK plugs that most 308 folks are using. If you search you'll find the recommendations as I can't remember the number. Your misfire could easily be one or more fouled plugs, so don't immediately fear the worst. I used to have a problem with fouled plugs but resolved it by changing my starting technique. (1978 GTS U.S.). I figured out that I was fouling plugs on my cold starts by not holding higher rpms until every cylinder was firing happily. Now when my engine lights up, I hold it at 2500 to 3000 for a half minute or so which is much higher than I like with a cold engine. However, the owners manual calls for 3000 to 4000 rpm but I can't bring myself to do that! Anyway, my point is that it can be something very simple. Good luck!
I'd agree, start by going to fresh plugs. BPR6EIX is a popular choice. One of many old discussions: http://www.ferrarichat.com/forum/technical-q-sponsored-algar-ferrari/5632-308-spark-plugs-types-recommandations.html While the exotic plugs are good, they're still not immune to fouling. If you still have more fouling issues to sort out after the work you've just done, you can use the spark plug cleaner from Harbor Freight on your air compressor to good effect.
