I have a 1979 single distrib with electronic ignition. Having used the car yesterday with no problems I think the magical Ferrari electrical fairy paid me a visit last night. The car revs fine with no load on the engine. However when driving it will only go to 2000 rpm if i push the accelerator to try and get higher the car feels like it is slowing down and eventually will backfire. There is no fuel starvation problem. Wondering if anyone has any suggestions, I have been told that the sensors from the dizzy back to the coils do go bad on these cars frequently, can anyone concur that this is the symptom or do you have any other suggestions Thanks Tom
How about something in the advance not behaving right? Is it a fully electronic system (advance and firing), or is the advance still a mechanical device?
Not sure, never taken the dizzy apart, it has electronic sensors but not sure of the advance, there are many versions of this system apparently and it is impossible to tell without dismantling When I put the engine back together in April I could only get 18 deg advance at 5000rpm using the strobe but everything was running fine until yesterday.
Out of curiosity (I've also got a '79, but in the form of a GT4), what's the "name" of the ignition setup you've got? If a previous owner had it installed, do you have any info on where they had it done? I'm looking at a single-dizzy setup to replace my PermaTune ignition system, and the one I'm looking at is called "Black Stallion", out of Australia but is available locally at Carobu in here in CA or from Superformance in the UK. FWIW, your car sounds like it's doing what mine someetimes does if I sit at a traffic light for a *really* long time with the engine fully warm and then take off. Although I can usually get more than 2k RPM out of it, the other symptoms (a feeling of slowing down, no power, and an eventual backfire) are spot on. Also, my car is jetted really lean right now (still set up to pass emissions), and I probably need to take care of that.
Have to say that that doesn't sound good in any case. I'm not aware of different versions of the "stock" single-dist electronic 308 ign. systems, but it is true that many ign. systems get modified/replaced over time. The schematic and wording in the 155/78 OM would lead me to believe that the stock advance mechanism for this particular set-up is a mechanical system inside the dist., but I don't know that for sure.
Hi, although I've had an European 79 GTS, I guess there's no big difference when one speaks 'bout the Mallory electronic single distr.ignitions of this era. I've restored it before. It has a mecanical centrifugal advancesystem. It is recommended to mark your distributor and rotor. Then take the D.thing off and check out of the mechanism is'nt dried out. It has to be greased and rotate freely. actually there's little that can go wrong with it. It can happen that the greas is fully hardened out and the centrifugal weights are not doing their job anymore. Also check the wires in the distributor in de area of the passage through the housing. They tend to dry out completely en isolation is then gone to heaven. Magneti Marelli has made these parts almost identical for the Alfa Romeo Sprint. Complete with the special connectors. Here (at least in Europe) these parts are easy available. Nobody seems to notice but with slight adaption these parts are interchangable. So try It. Succes !! Marcel
Your advance mechanism is stuck or worn-out as you should achieve 35 deg. BTDC @ 5000RPM. On my distributors, the problem was caused by the spring-loaded pins that had been flat-spotted where they made contact against the advance cup wall. This wear had taken up advance movement and so, it would bottom-out after only a few degrees (similar readings to you). As for the type of distributor, it's basically Magneti-Marelli's version of a Pertronix set-up (hall-effect magnetic triggers in the dizzy send signal to a solid-state processor/controller, which then attaches to the coils. The difference of Pertronix is that it attaches directly to standard coils). If any of these components fail, the car would not run at all. Image Unavailable, Please Login Image Unavailable, Please Login
Thanks guys, I have been playing about with the ignition system and it is definitely a broken sensor to the coil (probably coupled with a stickly advance weight) I have taken it off the car and I amd sending it across to Mike Elliot in Superformance for a rebuild. Cheers for all the advice guys. Tom
