FARTING 308 STYLE

It looks like you have an US spec gtsi like mine. There are several quick tests I would run. First I would pull the extenders and inspect them for buns and ensure they were attached to the plugs properly. While the extenders are out, blow out the spark well with compressed air. Alot of times water can get into a well and create a path to ground that can act random. Next check the timing at idle. At idle with vacuum the timing should be 3 deg atdc (this is the latest ignition timing I have ever seen on a car). With the vacuum line disconnected timing should avance to 6 deg btdc. Check both banks. Next is start pulling plugs and looking at them. If that doesn't help PM me. I will be with 2NA tomorrow and we should be able to figure it out.

 

Check your warm-up regulator operation and control fuel pressure.

 

FWIW - check the rotors again - I replaced mine and about a year later on one of the screws on the top of the rotor backed out and cracked the rotor but not the cap - just saying.....

 

If you have what appears to be ignition problems, even thought you have fresh rotors, caps, wires, extenders and plugs, and the problem is still there, it could be RPM sensors, TDC sensors, or the Digiplex units themselves.

I found that my 308 ran crappy for 2 reasons, 1) the RPM sensor was going bad (no output) and 2) one of the 2 Digiplexes was bad, no more advance, not sure if it was a pneumatic problem, a mechanical problem, or an electronic problem.

Since I can't find anyone out there who even claims to know how to diagnose and fix a Digiplex ( I contacted many vendors) I got a distributor-less ignition system out of a Mustang and put that it.

There are a number of legitimate Ferrari-grade aftermarket replacement ignition systems that can replace the tuckered out digiplexes.

If there is anyone out there who can point to a competent digiplex rebuilder, I'd be impressed. I could not find anyone.

 

the ignition system has 4 coils, does not use the Ferrari coils. It's a wasted spark system, when it fires the firing cylinder, it also fires the complementary cylinder at the top of the exhaust stroke at the same time. The spark plug firing at the top of the exhaust stroke does nothing. In theory the plugs may wear faster, but my Mercury with the same ignition system has 80,000 miles and I have never changed the plugs so it really does not matter.

 

I don't know what shop manual you are using, but the 1982 Mondial shop manual has the WRONG firing order. How the Hell did that happen ? I hope they fired that guy.

I went to google images and searched on Ferrari V8 firing order engine plates and found some photos of old Dino engines that had firing order plates on them. For some reason the 308 does not have this plate, but it's very useful.

BTW I have never found a 308 GTSi shop manual so I use the Mondial Manual on line.

I took a huge magic marker and wrote the (correct) 308 firing order on the shop light over my bench. I pulled my hair out for a long time over that incorrect firing order in the Mondial manual.
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That's fantastic