I have owned a 400 I 1984 Auto (49829) for 35 years and after an overhaul of the distributor the right cylinder line works randomly On the workshop manual D3 ignition distributor it is indicated: "take care not to exchange the two springs of each centrifugal element since they have different loads" if an error occurs what does this affect the operation of the engine is it possible that cylinders 1 to 6 work less well than the others? and how to recognize the correct position of the springs ?
the ignition curve is two steps: initially, raises fast due to the softer spring then slower advance increase once the second spring kicks-in. If you mix the springs, car will be sluggish but should work. I suspect the leads were put the wrong way, as the second bank is to be 180° apart on the distributor cap. See https://www.ferrarichat.com/forum/threads/distributor-plug-lead-order-and-rotor-direction-help-needed.642979/#post-147933239.
If you mix up the springs, it should have an equal effect on all cylinders. Attached is a photo record I made when stripping down my distributor for the very purpose of putting it back together the same way! What you see are the two centrifugal weights and the springs etc. Image Unavailable, Please Login The parts are as-removed and before cleaning. The measurements shown are in mm and show the overall lengths of the springs and the associated pins. After reassembly I measured the advance curve on a home-brew test rig, and it was very close to specification, so I'm confident the photo shows the correct positioning.
As @pattorpey said : mismatching the spring will not affect a single bank, you will get slightly less advance (on both banks) which would make the engine slightly less powerful in the mid-range. At idle and full throttle there should be zero effect. Given how much work is involved in removing the distributor, you should work on more probable causes (and in any cases it's easy to check with a timing light if the advance is correct at 3000rpm without removing the dist.).
Hello Thank you for your help I have in stock 6 new injectors and a new fuel pump in a first time I will change them maybe it is a fuel injection problem. In a second time i will control again the advance. I will keep you informed of the results Best regards
Hello, After re-adjusting the advance and changing the fuel pump and the 6 injectors on the right side, the engine runs perfectly again, I did not need to dismantle the distributor, thank you for your help
Thank you but this would be difficult, I live in New Caledonia, a French island in the South Pacific, and maintaining my 400 is not easy.
Hello, there is at least another owner of F400 in New Caledonia, a member of Ferrari Club 400 who lives in Nouméa.
